Identification Information

Citation:

Originator: Stanley A. Mertzman, Richard W. Hazlett, Stephen G. Weaver, Isaac P. Weaver, Andrew J. Gavin, Martha S. Gilmore, Caitlin Gorman, Lindley F. Hall, Hal H. Newell III, Karyn E. Powers, James T. Rowe, Jonathon F. Stiehl, and Benjamin Surpless

Publication Date: 2011

Title:

Open-File Report O-11-03: Preliminary Geologic Map of the Lake of the Woods North 7.5′ Quadrangle, Klamath County, Oregon

Publication Information:

Publication Place: Portland, Oregon

Publisher: Oregon Department of Geology and Mineral Industries

Description:

Abstract: This data set contains the information used to create the Preliminary Geologic Map of the Lake

of the Woods North 7.5′ Quadrangle for Open-File Report O-11-03. This map is one of a series of geologic maps created for quadrangles in south-central Oregon in the area of the Cascade Mountains just to the west of Klamath Lake in Jackson and Klamath Counties (and and including a small area of northern California at the Oregon and California border).

The digital raster Graphic (DRG) of the 1985 provisional edition of the U.S. Geological Survey (USGS) 7.5′ Lake of the Woods North quadrangle provides the base map on top of which have been placed geospatial vector format layers of the geologic units, unit boundaries/contacts, and faults; and point data format layers of the analyzed rock sample collection locations and volcanic centers. The geologic units and their boundaries were determined based on a combination of observations from the field and of hand-sample, thin-section, and geochemical analyses of 114 samples collected from within the Lake of the Woods North USGS 7.5′ quadrangle as well as of relevant samples collected from surrounding USGS 7.5′ quadrangles. Although the chemistry data and thin-section observations were used in creating the map, the units are meant to be field-mappable, that is, recognizable by the study of outcrops in the field.

The various layers (geologic units, samples, etc.) of the map were digitized in MapInfo Professional v.7.0 from drawings on paper quadrangles, UTM coordinates, or maps from student research reports. Rock samples were collected and analyzed by X-ray fluorescence (XRF) in 1984, 1986, 1991, 1992, 2002, and 2009. A total of 14 samples from within the Lake of the Woods North 7.5′ quadrangle, plus several from surrounding quadrangles (but from units found in the Lake of the Woods North quadrangle), were dated using K-Ar (13 specimens) or 40Ar/39Ar (two specimens) dating methods. The major and trace elemental chemistry data and ages (if dated) of specimens collected within the Lake of the Woods North quadrangle are made available in the samples table of this data set.

Purpose: These data were collected and compiled in order to better understand the local geology and

geologic history, to create a field-mappable geologic map of the U.S. Geological Survey 7.5′ Lake of the Woods North quadrangle to be published as Open-File Report O-11-03, and to make available the collected chemical and age information that may be useful in various forms of study of this volcanic region. The map is intended for a diverse audience with varying amounts of geologic understanding. This is one of a series of geologic maps of USGS 7.5′ quadrangles in the south-central region of Oregon to be published by the Oregon Department of Geology and Mineral Industries.

Supplemental Information: There are several different files and file formats in this data set. The geologic

units table, unit boundaries/contacts table, samples table, faults table, and volcanic centers table were created in MapInfo Professional version 7.0 and the .TAB files can be opened using MapInfo software. These data were later translated to ESRI compatible file formats using the MapInfo Universal Translator extension. These translated files were then arranged and set up to properly display the data when opened in the ESRI ArcMap software.

There is a MapInfo workspace (.WOR) file that opens the georeferenced USGS Lake of the Woods North 7.5′ quadrangle raster image and the other Lake of the Woods North quadrangle tables mentioned above (LOWN.WOR). There is also an ArcMap file (.MXD) which contains the georeferenced USGS Lake of the Woods North 7.5′ quadrangle and the geologic units, unit boundaries, samples, faults, and volcanic centers shapefiles and accompanying attribute tables (LOWN.MXD).

Time Period of Content:

Multiple Dates/Times:

Calendar Date: 1984, 1986, 1991, 1992, 2002, and 2009.

Currentness Reference: ground condition and 2011 is the publication date

Status:

Progress: Complete

Maintenance and Update Frequency: Unknown

Spatial Domain:

Bounding Coordinates:

West Bounding Coordinate: -122.25

East Bounding Coordinate: -122.125

North Bounding Coordinate: 42.5

South Bounding Coordinate: 42.375

Keywords:

Theme:

Theme Keyword Thesaurus: none

Theme Keyword: geologic map

Theme Keyword: map of surface geology

Theme Keyword: surface geology

Theme Keyword: volcanoes

Theme Keyword: Oregon volcanoes

Theme Keyword: volcanic flows

Theme Keyword: lava flows

Theme Keyword: units

Theme Keyword: formations

Theme Keyword: formation boundary

Theme Keyword: contact

Theme Keyword: samples

Theme Keyword: rock samples

Theme Keyword: geochemistry

Theme Keyword: chemistry

Theme Keyword: age-dated

Theme Keyword: volcanic center

Theme Keyword: geospatial vector format

Theme Keyword: digital raster graphic

Theme Keyword: drg

Theme Keyword: topographic map

Theme Keyword: topographic quadrangle

Theme Keyword: USGS quadrangle

Theme Keyword: Open-File Report

Theme Keyword: Open-File Report 11-03

Place:

Place Keyword Thesaurus: none

Place Keyword: Oregon

Place Keyword: south-central Oregon

Place Keyword: Southern Oregon

Place Keyword: Klamath County

Place Keyword: Oregon volcanoes

Place Keyword: Lake of the Woods North USGS 7.5′ quadrangle

Place Keyword: Lake of the Woods North quadrangle

Place Keyword: Lake of the Woods North

Place Keyword: Rainbow Bay

Place Keyword: Pearce Point

Place Keyword: Rye Spur

Place Keyword: Lake of the Woods

Place Keyword: Long Lake

Place Keyword: Fourmile Lake

Place Keyword: Badger Lake

Place Keyword: Woodpecker Lake

Place Keyword: Lake Aphis

Place Keyword: Lake Clovis

Place Keyword: Lake Bernice

Place Keyword: Lake Janice

Place Keyword: Bull Swamp

Place Keyword: Wolf Lake

Place Keyword: Lake Malice

Place Keyword: Dry Creek

Place Keyword: Billie Creek

Place Keyword: Seldom Creek

Place Keyword: Fourmile Creek

Place Keyword: Lost Creek

Place Keyword: Long Creek

Place Keyword: Horse Creek

Place Keyword: Camp McLoughlin

Place Keyword: Fourmile Rock Pit

Place Keyword: Lost Creek Cinder Pit

Place Keyword: Pelican Butte Road

Place Keyword: Oregon Route 140

Place Keyword: Fourmile Lake Road

Place Keyword: Winema National Forest

Place Keyword: Mountain Lakes Wilderness

Stratum:

Stratum Keyword Thesaurus: none

Stratum Keyword: surface

Stratum Keyword: surface geology

Stratum Keyword: surficial

Stratum Keyword: surficial formations

Stratum Keyword: surface formations

Stratum Keyword: surface units

Stratum Keyword: surficial units

Stratum Keyword: upper strata

Stratum Keyword: surface strata

Stratum Keyword: volcanic strata

Stratum Keyword: volcanic

Stratum Keyword: surficial volcanic deposits

Stratum Keyword: lava flows

Stratum Keyword: surficial lava flow

Stratum Keyword: Quaternary sediments

Stratum Keyword: Quaternary landslides

Temporal:

Temporal Keyword Thesaurus: none

Temporal Keyword: 3.6 Ma

Temporal Keyword: 3.6 million years

Temporal Keyword: present

Temporal Keyword: 3.6 million years ago to the present

Temporal Keyword: late Cenozoic

Temporal Keyword: upper Cenozoic

Temporal Keyword: Quaternary

Temporal Keyword: 3.600 Ma

Temporal Keyword: 3.600 million years

Temporal Keyword: Less than 3.600 million years

Temporal Keyword: 3.600 million years ago to the present

Temporal Keyword: Middle Pliocene to Holocene

Temporal Keyword: Pliocene to Holocene

Temporal Keyword: Pliocene

Temporal Keyword: Tertiary

Temporal Keyword: Neogene

Temporal Keyword: Pleistocene

Temporal Keyword: Holocene

Access Constraints: none

Use Constraints: Acknowledgement of the authors and the Oregon Department of Geology and Mineral Industries would be appreciated in products derived from these data.

Point of Contact:

Contact Person Primary: Stanley A. Mertzman

Contact Address:

Address Type: mailing and physical address

Address: Stanley A. Mertzman, Franklin and Marshall College,

Department of Earth and Environment, PO Box 3003

City: Lancaster

State or Province: Pennsylvania

Postal Code: 17604

Contact Voice Telephone: 1-717-291-3818

Contact Electronic Mail Address: stan.mertzman@fandm.edu

Contact Instructions: contact via electronic mail is preferred

Browse Graphic:

Browse Graphic File Name: LOWN30x36.pdf

Browse Graphic File Description: The LOWN30x36.pdf file contains

the Preliminary Geologic Map of the Lake of the Woods North 7.5′ Quadrangle, Klamath County, Oregon of Open-File Report O-11-03. This map was made from the data provided in this data set. The basic image in this map (the 1985 Provisional Edition USGS Lake of the Woods North 7.5′ quadrangle overlain by the formations, formation boundaries/contacts, faults, and sample symbols) was created in MapInfo Professional version 7.0 using the data available in this data set (LOWNQuadforTransparent.TAB, LOWNUnits.TAB, LOWNUnitBounds.TAB, LOWNFaults.TAB, and LOWNSamples.TAB). This image was exported from MapInfo Professional v. 7.0 as a Photoshop Document (.PSD) at a zoom of 1 inch = 1.4 miles, a window size of 7.99 miles (in the export options, the actual window size was doubled from 5.72 inches to 11.44 inches), and with a resolution of 600 pixels per inch. The colors of the resulting .PSD file were adjusted in Adobe Photoshop CS3 to match USGS CMYK color standards. The image was then opened in Adobe Illustrator CS3 (and in CS5 during later edits) where its size was increased by 184.7999% to make the map scale 1:24,000. The scale was then checked manually within Adobe Illustrator CS5. The samples’ map numbers, the formation labels, and the rest of what is seen on the map sheet, such as the time rock chart and the legend, were added to the map sheet in Adobe Illustrator CS3 and CS5. The resulting 30 inch x 36 inch Adobe Illustrator image was saved as a Portable Document Format (.PDF) file and the result is the image of the geologic map seen in the file LOWNMap30x36.pdf.

Browse Graphic File Type: PDF

Native Data Set Environment: The majority of the data files in the data set used to make the Preliminary Geologic Map of the Lake of the Woods North 7.5′ Quadrangle, Klamath County, Oregon of Open-File Report 11-03 was originally created using MapInfo Professional software version 7.0 running under a Microsoft Windows 2000 Professional operating system. The data that were digitized in this environment were the geologic units, the unit boundaries, the faults, the sample locations, and the volcanic centers layers. These files were modified using MapInfo Professional software version 7.0 running under a Microsoft Windows XP Professional version 2002 Service Pack 2 operating system. The USGS 7.5′ Lake of the Woods North quadrangle digital raster graphic (drg) was obtained from an external source (the University of Oregon Libraries website, http://libweb.uoregon.edu/map/map_section/search.html) and was produced in a different and unknown environment. However, in order to make a version of this USGS quadrangle drg that would make its white and green areas transparent (so that the map could overlay the formations layer and the formations could show through) the digital USGS quadrangle drg was modified from the state in which it was originally obtained. This modification was done using Adobe Photoshop version 5 and the resulting image of the quadrangle was manually georeferenced in MapInfo Professional version 7.0. The data were at times accessed and modified in MapInfo Professional version 7.0 running under a Microsoft XP operating system, and the final files were made on such a PC with Windows 7 Ultimate running MapInfo Professional version 10.5. The data from the Lake of the Woods North quadrangle samples table have been exported from MapInfo Professional version 7.0 and version 10.5 at least one time and opened in Microsoft Excel for addition or modification of certain attributes, particularly chemistry data. The Microsoft Excel file was then reopened in MapInfo Professional version 7.0 or version 10.5. The files of this data set have been saved and backed-up on various hard drives at various times. The most up-to-date MapInfo Professional formatted files (DAT, ID, MAP, PSD, TAB, TFW, TIF, and WOR) have a total size of 9.85 MB.

After the data set had been produced in MapInfo Professional version 7.0 or 10.5, the files were converted using MapInfo’s Universal Translator extension to produce files that could be opened with ESRI ArcMap software version 10.0. This was done by converting the MapInfo TAB files into ESRI SHP format files. The USGS quadrangle drg was reopened within ESRI ArcMap. Further modification of the data files occurred within ESRI ArcMap, such as adjustment of attribute names in the attribute table, adjustment of symbol shapes and colors, and setting of the formation regions’ colors to make these features similar to how they appear in the MapInfo Files and on the Open-File Report geologic maps. The ESRI-formatted files (MXD, DBF, PRJ, SBN, SBX, SHP, SHX, AUX, RRD, TFW, and TIF) have a total size of 17.3 MB.

Data Quality Information

Attribute Accuracy:

Attribute Accuracy Report: The attribute accuracy was tested in several ways. For sample, unit boundary,

fault, and volcanic center location attributes (UTM coordinates), accuracy was assessed by comparison of on-screen representations of the location (digital maps on the computer screen) to hard copy versions (hand-drawn or similarly-demarcated locations and boundaries on top of paper USGS quadrangles [when available]). On several occasions, the digitized versions of the Lake of the Woods North 7.5′ quadrangle were printed out on paper with the symbol locations, formation/unit boundaries, and faults demarcated. The print-out was then assessed by the chief geologist of the project, Stanley A. Mertzman. The final digital version was also assessed by Stanley A. Mertzman.

The UTM coordinates of the samples provided in the attribute table have a precision that does not reflect that with which their locations on the map were determined. The precision reflects the values that were assigned using MapInfo Professional version 7.0’s or 10.5's Coordinate Extractor extension after manual placement (digitization) of the sample locations on the drg of the USGS 7.5′ Lake of the Woods North quadrangle based on comparison with the original paper quadrangles or other maps on which locations were drawn, or in some cases, based on previously-rounded (to the nearest 10 m) UTM coordinates for samples not shown on the original paper map(s). The accuracy and precision of the locations drawn on the original paper maps may vary. Prior to the year 2000, sampling locations were originally determined by use of a Brunton compass in the field and these data were later translated to the 1:24,000 USGS 7.5′ quadrangles using plastic overlay cards marked with 1:24000 scale UTM coordinate grids or tick marks at relevant, repeated intervals. After the year 2000, Magellan GPS units were used in the field to determine a sample’s collection location, and again these coordinates were placed on the 1:24,000 scale USGS quadrangles using the appropriate plastic overlay card with UTM units.

The Public Land Survey System (PLSS) attributes (Ľ of Ľ Section, Ľ Section, Section, Township, and Range) in the Lake of the Woods North samples table were created in a manner so as to be as accurate as possible, but have not been tested for accuracy beyond the checks that occurred during their production. Typically the Township and Range attribute values were assigned by selection of all samples that occurred within either manually created or downloaded polygons of the Township and Range boundaries. Samples near a Township or Range grid line were more carefully studied on the screen to check that the sample really did lie within the supposed Township. The Section attribute was assigned based on a sample’s location in relation to the PLSS section grid as represented on the drg of the Lake of the Woods North quadrangle in MapInfo (the sections are the small quadrangles demarcated by dashed red lines with the section numbers in their centers [where possible]).

The Ľ of Ľ Section and Ľ Section attributes were assigned for each sample based on downloaded grids (http://www.geocommunicator.gov/GeoComm/lsis_home/home/index.shtm) which displayed the boundaries of the Ľ of Ľ Sections and Ľ Sections of Townships. Because the Section and Township boundaries did not always line up perfectly with those of the underlying quadrangle DRG, at times attributes of samples close to lines in this grid had to be assigned based on mental adjustments, or at times the use of MapInfo Professional version 7.0’s Ruler tool, by a technician. For this reason, the accuracy of the Ľ of Ľ Section and Ľ Section attributes may be questionable in some cases, particularly in those samples which lie close to the boundaries which demarcate these location descriptors.

The accuracy of a sample’s Unit attribute was tested by a visual check of the sample’s location in relation to the unit boundaries as displayed in MapInfo Professional version 10.5 and by analysis of the chemical data.

The accuracy of the chemical data is dependent on many factors not discussed here. The samples were analyzed by X-ray fluorescence (XRF) at various times and possibly by different machines. All that will be said is that the accuracy of the XRF chemical data is monitored and assessed during the measurement procedure by using an instrument monitor (to account for local climate and machine conditions on the day of measurement), by running several well-measured standards in every batch, and by analyzing the totals counts. That the chemical attributes of each sample in the data table match the originally assigned data from the XRF instrument was insured by copying the data from the original Excel data files that contained the chemistry information provided by the XRF spectrometer and pasting them into an Excel spreadsheet which eventually became the attribute table of the LOWNSamples.TAB MapInfo table. All of the chemical data were derived from these original Excel files, except for those of several of the age-dated samples, which may have values copied from a previous publication in Oregon Geology by Stanley A. Mertzman (2000). That the chemistries of the dated samples were correctly copied into the data table was checked by comparison of the digital data to the data printed in the publication. In cases where there were differences between the values in the original XRF results and those in the 2000 publication (Mertzman, 2000), the values in the data table were changed to match those of the 2000 publication.

The colors of the units are consistent between adjacent quadrangles mapped in this project and were created as the RGB (only color mode allowed in MapInfo Professional version 7.0) equivalents of standard USGS CMYK colors.

Logical Consistency Report: The boundaries of the Lake of the Woods North unit polygons within the units table (LOWNUnits) have been checked for self- intersections, overlaps, and gaps using MapInfo Professional version 10.5 and no self-intersections, overlaps, or gap problems were detected. The edges of unit polygons have also been checked against those mapped in adjacent USGS 7.5′ quadrangles as part of this project, but available in other data sets (the incomplete Pelican Butte quadrangle to the north [unpublished at the time of editing this document (01/08/11)], the Lake of the Woods South quadrangle to the south [OFR O-07-13 (Mertzman et al., 2007)], the Mt. McLoughlin quadrangle to the west [unpublished at the time of editing this (01/08/11)], and the incomplete Pelican Bay quadrangle to the east [unpublished at the time of editing this (01/08/11)]). All of the boundaries (where present) were found to fit, and all of the points at the quadrangle corners were found to align perfectly if unit layers were present (including those of units in the Aspen Lake quadrangle to the southeast [OFR O-07-17 (Mertzman et al., 2007)] and the Brown Mtn. quadrangle to the southwest [OFR O-07-09 (Mertzman et al., 2007)]). The unit boundaries polylines (from the file LOWNUnitBounds) were drawn in a separate layer on top of the formations/units layer using the trace function that is available in the MapInfo Professional version 7.0 software.

There are seve pairs of samples with duplicate coordinates in the Lake of the Woods North samples data table (LOWNSamples) due to the collection of more than one sample from the same location or possibly from multiple XRF analyses of different parts of the same sample.

Completeness Report: All field-mappable units (and thus unit boundaries) in the USGS 7.5′ Lake of the Woods

North quadrangle have been mapped. At least one sample (not necessarily within the USGS Lake of the Woods North 7.5′ quadrangle) from each volcanic unit present in the quadrangle has been age-dated (except for the Andesite of Brown Mountain [Qabm]). All known faults and volcanic centers within the Lake of the Woods North quadrangle have been mapped and the layer containing the volcanic centers’ locations have been included in this data set. All samples known to have been collected within this quadrangle and analyzed by X-ray fluorescence (XRF) by Professor Stanley A. Mertzman, students, or a lab technician have been mapped and are included within this data set. All chemistry results from the XRF analyses have been included in the attribute table of the samples data file (LOWNSamples). All map numbers, sample numbers, ages (applicable only to dated samples) in millions of years (Ma), Public Land Survey System (PLSS: Ľ of Ľ Section, Ľ Section, Section, Township, and Range according to the Willamette meridian and base line), UTM coordinates (North American Datum of 1927: Zone 10), unit membership, and lithology (based on the total alkalis versus silica [TAS] classification method for volcanic rocks described by Le Maitre [2002]) have been included in the attribute table of the samples data file. The unit's symbol, name, geologic time scale age, and radiometrically-determined age(s) are the attributes of the Lake of the Woods North units table (LOWNUnits). The number attribute in the LOWNUnits table allows the stratigraphically accurate listing of the units in the table. The attributes of the faults table indicate whether the fault’s location is approximate or concealed and inferred (Appr_or_Conc); describe what kind of fault it is (Type_of_Fault); and indicate the relative direction of the hanging-wall/down- dropped block to the fault (Notes). The attributes of the volcanic centers table provide their UTM Easting and Northing locations (UTM_E_m and UTM_N_m) according to the North American Datum of 1927 for the US: Zone 10 (NAD 27: Zone 10) as determined using the Coordinate Extractor extension in MapInfo Professional v. 7.0. As with the sample location coordinates, the precision of the UTM coordinates of the volcanic centers is greater than that with which the locations were assigned due to the precision of the results the Coordinate Extractor produces.

Positional Accuracy:

Horizontal Positional Accuracy:

Horizontal Positional Accuracy Report: The horizontal positional accuracy of the digitized data

with regard to the original paper maps has been checked by visual comparison of the digitized sample locations, formation boundaries, faults, and volcanic centers to the original paper maps when possible. The positional accuracy of the original sample locations on the original paper maps may vary depending on the location-determining methods used as discussed above (Brunton compass before 2000 or Magellan GPS thereafter). The positions of the unit boundaries are approximate and their accuracy has not necessarily been field tested. Analysis of the collected samples (chemistry, hand-sample, and thin sections) and familiarity with the area from lots of time spent in the field by experienced geologists ought to ensure reasonable accuracy of the mapped unit boundaries, although this is not quantifiable.

Lineage:

Source Information:

Source Citation:

Originator: U.S. Geological Survey

Publication Date: 1985

Title: Lake of the Woods North Quadrangle: Oregon–Klamath Co. 7.5 Minute Series (Topographic)

Edition: Provisional Edition 1985

Geospatial Data Presentation Form: map and raster digital data (digital raster graphic [drg]) of map

Series Information:

Series Name: U.S. Geological Survey 7.5 Minute Series Topographic Quadrangles

Series Issue: Lake of the Woods North, Oreg.: Provisional Edition 1985: 42122- D2-TF-024

Publication Information:

Publication Place: Denver, CO or Reston, VA

Publisher: U.S. Geological Survey

Other Citation Details: A drg of this map can be downloaded from the University of Oregon Libraries website.

Online Linkage: UO Libraries website:

http://libweb.uoregon.edu/dc/24k_lookup/displaymap.php?ohio_code=42122d2

Source Scale Denominator: 24,000

Type of Source Media: Paper and Online

Source Time Period of Content:

Time Period Information:

Multiple Dates/Times:

Calendar Dates: 1980, 1982, 1985

Source Currentness Reference: 1980 corresponds to the year in which aerial photographs were taken; the map was field checked in 1982; and the map was edited and published in 1985. The year of production of the particular drg used in the data set is not currently known.

Source Citation Abbreviation: 42122d2

Source Contribution: The USGS Lake of the Woods North 7.5 minute paper quadrangle was used as the base map on which the geology of the quadrangle was mapped by Stanley A. Mertzman, his colleagues, and students (the exact version[s] of the map[s] used as the original base maps is not currently known). A downloaded drg of the Lake of the Woods South 7.5 minute quadrangle (42122d2) was used as the base map for this data set onto which the sample locations, units, faults, and volcanic centers were copied (digitized) from a paper version (or versions) of the map(s) produced by the geologists involved in this project. It is also possible that the sample collection locations came from UTM coordinates provided in a report by one of the geologists.

Process Step:

Process Description: The first step in the production of this data set was the collection of rock samples and observations from the field. The samples’ chemistries were determined by X- ray fluorescence (XRF) spectroscopy (see http://fandm.edu/x7985.xml for an overview of the XRF spectroscopy preparation and analysis procedure at Franklin & Marshall College’s XRF laboratory). The hand-samples were carefully analyzed and described. Thin sections of the rocks allowed further description of certain samples by analysis with a petrographic microscope. A sample’s collection location was determined in the field using a Brunton compass prior to 2000, and with a Magellan GPS unit after 2000. The sample locations were marked on paper versions of the USGS 7.5′ Lake of the Woods South quadrangle (and in some cases, only the UTM coordinates were recorded or retrievable for use in digitization). These locations were digitized using a georeferenced (to the North American Datum of 1927 [NAD 27] zone 10 horizontal datum) drg of the quadrangle in MapInfo Professional version 7.0 by placing a point (node) in a layer above the drg at the location identical to the sample’s location on the paper map. If a sample was not present on a map, but the UTM coordinates of its collection location were known, these coordinate values were used to plot the sample’s collection location in MapInfo. This process was the first step in the production of the Lake of the Woods South samples table (LOWNSamples); it produced point data from which the UTM coordinates, if not already known, could be extracted to the attribute table. Please note that the precision of the UTM coordinates does not necessarily reflect the precision with which they were originally obtained, but represents the precision obtained when extracting the coordinates of the points (with MapInfo Professional version 7.0’s Coordinate Extractor tool) after they were digitized from the paper maps.

The LOWNSamples attribute table was exported from MapInfo Professional v. 7.0 at least one time to Microsoft Excel, where other sample attributes were added and or modified (such as lithology and chemistry data). These Excel spreadsheets were then imported back into MapInfo Professional version 7.0 or 10.5 and the previously extracted UTM coordinates were used to re-plot the sample locations over the 7.5′ quadrangle drg. The drg of the quadrangle was also used in assigning some of the Township, Range, and Section attributes to the samples. Downloaded PLSS grids also aided in assigning these and other PLSS attributes (Ľ of Ľ section, Ľ section) to the samples table.

The combination of the analyses of collected samples and a familiarity with the area from a lot of time spent in the field allowed Stanley A. Mertzman to determine and discriminate between the units present within the Lake of the Woods North 7.5′ quadrangle and to draw the approximate locations of their boundaries on the paper USGS 7.5′ topographic maps. These boundaries were then digitized in the same manner as sample locations, by copying their locations from the paper map to a MapInfo layer on top of a drg of the same map (USGS 7.5′ Lake of the Woods North quadrangle (42122d2)). This was done using the polygon tool in MapInfo Professional version 7.0. The boundary of the unit on the map (contact) (LOWNUnitBounds MapInfo Table) was digitized as the boundary of the polygon in MapInfo. The unit polygons were colored based on RGB equivalents of standard USGS CMYK colors. The unit ages, names, and symbols (abbreviated names) were added to the attribute table at a later stage of the process. It was decided that a separate layer (file) should be made for the unit boundaries (contacts) within the quadrangle because the edges of the unit polygons did not necessarily correspond to the actual unit boundaries. The edges of the unit polygons were limited by the quadrangle boundaries, so although many units extend beyond the boundaries of the Lake of the Woods North USGS 7.5′ quadrangle, the polygons for this data set were limited to the area of the quadrangle.

In order to make a layer (LOWNUnitBounds) that corresponded to the actual unit boundaries (ground-surface contacts between two rock units), the true unit boundaries (not those cut off at the quadrangle’s edges) were made by tracing (using MapInfo’s trace function) all of the unit polygons’ edges, except those that corresponded with the 4 sides of the quadrangle. This process created the polylines that now represent the unit

boundaries/contacts in this data set (LOWNUnitBounds).

The volcanic centers’ locations (LOWNVolcCenters) were originally determined from field observations and sample analyses. Their locations were marked on a paper version of the quadrangle with temporary stickers and then digitized by copying the location to the identical spot on the drg of the quadrangle. The UTM coordinates of these locations have been extracted into the volcanic centers attribute table using MapInfo version 7.0’s Coordinate Extractor tool. Please note that, like the precision of the samples’ UTM coordinates, the precision of the volcanic centers UTM coordinates does not reflect that with which the location was determined, but is the result of using MapInfo v. 7.0’s Coordinate Extractor Extension that outputs the data in a certain format.

The faults’ locations were primarily determined based on field observations, but in certain locations were inferred based on the local topography and geology combined with the consideration of the location of faults that went to the edges of adjacent 7.5 minute USGS quadrangles.

After the creation of final forms of all of the necessary files in MapInfo, the MapInfo Universal Translator Extension was used to convert the MapInfo-formatted data set to ESRI-format files. This involved converting the mapinfo TAB files of the unit polygons, unit boundary (contact) polylines, sample points, fault polylines, and volcanic center points to shapefiles (SHPs). These files were opened and adjusted in ESRI ArcMap version 9.2. It should be noted that two additional fields (attributes) were created when the MapInfo TAB files were converted to ESRI-format files. These two fields are the “FID” and the “Shape*.” The “FID” numbers all of the objects in the data tables and the “Shape*” attribute tells what kind of data an object is (i.e., multipoint, polyline, or polygon). These added fields are not discussed with the rest of the attributes below. It should also be noted that certain attribute names of the ESRI-format files were changed by the program during their creation and were not able to be modified by the technician. In such cases, the alias of the attribute was changed to fit the original attribute titles (as shown below), but the names had to be left as they were converted.

The digital versions of the sample collection locations; units and unit boundaries; faults; and the volcanic centers locations were checked by visual comparison of the digital data on the computer screen (in MapInfo) or on printed copies to the original source paper maps. Furthermore, final printed or digital (PDF) versions of the resulting map(s) were assessed by the chief geologist of this project, Stanley A. Mertzman.

Source Used Citation Abbreviation: 42122d2

Process Date: 2011

Process Contact:

Contact Information:

Contact Person Primary:

Contact Person: Isaac Weaver

Contact Position: Research Assistant

Contact Address:

Address Type: mailing and physical address

Address: Isaac Weaver, Franklin and Marshall College, Department of Earth and Environment, PO Box 3003

City: Lancaster

State or Province: Pennsylvania

Postal Code: 17604

Contact Voice Telephone: Unavailable

Contact Electronic Mail Address:

isaacweaver@hotmail.com

# Spatial Data Organization Information

Indirect Spatial Reference: This data set contains the drg of the USGS 7.5′ Lake of the Woods North quadrangle and files with point data locations at which rock samples were collected from outcrops, polygons of the geologic units, polylines of the unit boundaries (contacts), polylines of the faults, and point data volcanic center locations for the U.S. Geological Survey 7.5 minute Lake of the Woods North quadrangle.

Direct Spatial Reference Method: Point, Vector, and Raster

## Spatial Reference Information

Horizontal Coordinate System Definition:

Planar:

Grid Coordinate System:

Grid Coordinate System Name: Universal Transverse Mercator

Universal Transverse Mercator:

UTM Zone Number: 10

Transverse Mercator:

Scale Factor at Central Meridian: 0.999600

Longitude of Central Meridian: -123.000000

Latitude of Projection Origin: 0.000000

False Easting: 500000.000000

False Northing: 0.000000

Planar Coordinate Information:

Planar Coordinate Encoding Method: coordinate pair

Coordinate Representation:

Abscissa Resolution: 0.01

Ordinate Resolution: 0.01

Planar Distance Units: meters

Geodetic Model:

Horizontal Datum Name: North American Datum of 1927

Ellipsoid Name: Clarke 1866

Semi-major Axis: 6378206.4

Denominator of Flattening Ratio: 294.9787

### Entity and Attribute Information

Detailed Description:

Entity Type:

Entity Type Label: Unit

Entity Type Definition: A rock unit (or simply unit), with regard to this data set, is a body of rock

with a limited range of lithological characteristics (as determined by analyses of outcrops and samples in the field and in the laboratory) that can be distinguished from other bodies of rocks by observations made in the field (such as analysis of outcrops or hand-samples collected from them). That is to say, a unit is field-mappable according to the definition used in the creation of this data set. Nevertheless, the chemistry data and other observations not possible in the field were still considered in determining and discriminating the units. In the Lake of the Woods 7.5′ quadrangle, a unit may represent one or more volcanic flows; vent deposits; or quaternary alluvium, landslide plus glacial, or glacial deposits. A unit has an age (or age-range), which has been determined by radiometric dating of collected samples (except for the Quaternary alluvium [Qal], Quaternary glacial [Qg], and Quaternary glacial plus Quaternary landslide deposits [Qg&Qls]; although samples were collected within the Qg area, these should be considered as float material). It should be noted that the vent deposit units (Qbv) could perhaps best described as a sub-unit of the units in which they are found (Andesite of Fourmile Creek [Qafc], Basalt of Chaffee Point [Qbcp], Basalt of Lost Creek [Qblc], Basalt of Pearce Point [Qbpp], Basalt of Woodpecker Lake [Qbwl], and Basaltic Andesite of Long Creek Peak [Qbalc]), but is classified separately due to the difference in lithology.

Detailed descriptions of the units found within the USGS 7.5′ Lake of the Woods North quadrangle are found in the Open-File Report O-11-03 (Mertzman et al., 2011). In this data set, the units are found in the LOWNUnits file and are colored polygons with their edges placed at the approximate locations of the contacts, except when limited by the quadrangle boundaries.

Entity Type Definition Source: See Mertzman et al. (2011) for detailed descriptions of the units found within the Lake of the Woods North quadrangle.

Attribute:

Attribute Label: number

Attribute Definition: This numbering system was used to order the geologic units stratigraphically in the MapInfo attribute table.

Attribute Definition Source: See Mertzman et al. (2011).

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 1

Range Domain Maximum: 32

Attribute Units of Measure: unitless

Attribute:

Attribute Label: Symbol

Attribute Definition: The symbol is a form of shorthand text, specific to a unit, that is created by

combining age and lithology information with an abbreviated form of the unit’s name. The symbol attribute is meant to be displayed on the pdf versions of the geologic map to save space while identifying the unit, or it can be displayed when viewing the data in MapInfo or ArcMap on a computer. It is intended that the symbol convey age, lithology, and unit name information. The first letter is capitalized and represents the period-age of the formation (T=Tertiary and Q=Quaternary). If the first letter of the symbol is a capital T, then the second letter represents the epoch-age of the formation (p=Pliocene and m=Miocene). It should be noted that these first two letters only represent the oldest dated age of the formation; that is, a unit’s age may span from period to period or epoch to epoch, but this cannot be discerned from the symbol. The remaining letters in the symbol indicate the dominant lithology of the formation and its name. The lithology (for volcanic units, b=basalt, ba= basaltic andesite, and a=andesite [based on weight percent silica(SiO2)]) comes first after the age information in the abbreviation of the unit’s name, which is usually based on an outstanding geographic or topographic feature present in the area of the unit. The vent deposits (Qbv) and the Quaternary sedimentary units (Qal and Qg) do not follow this pattern, are treated more generally, and only have the age information followed by a general lithology abbreviation because these units and sub-units (vent deposits) do not have specific names based on a geographic feature.

Attribute Definition Source: None

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: Qal

Enumerated Domain Value Definition: Alluvium (Holocene).

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Qg

Enumerated Domain Value Definition: Undifferentiated colluvium and alluvium (Pleistocene to Holocene).

Enumerated Domain Value Definition Source: Open-File Report O-11-03

(Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Qbv

Enumerated Domain Value Definition: Basaltic/basaltic andesite/andesite vent deposits (Pleistocene). This unit should be considered a sub-unit of the unit in which it is found. Qbv is present in six units of the Lake of the Woods North 7.5 minute quadrangle: Andesite of Fourmile Creek (Qafc), Basalt of Chaffee Point (Qbcp), Basalt of Lost Creek (Qblc), Basalt of Pearce Point (Qbpp), Basalt of Woodpecker Lake (Qbwl), and Basaltic Andesite of Long Creek Peak (Qbalc).

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Qabm

Enumerated Domain Value Definition: Andesite of Brown Mountain (Upper

Pleistocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Qafc

Enumerated Domain Value Definition: Andesite of Fourmile Creek (Middle Pleistocene).

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Qapb

Enumerated Domain Value Definition: Andesite of Pelican Butte (Middle Pleistocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Qawp

Enumerated Domain Value Definition: Andesite of Whiteface Peak (Lower to Middle Pleistocene).

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Qbalc

Enumerated Domain Value Definition: Basaltic Andesite of Long Creek Peak (Hill 6588) (Lower Pleistocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Qbwl

Enumerated Domain Value Definition: Basalt of Woodpecker Lake (Lower Pleistocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Qblh

Enumerated Domain Value Definition: Basalt of Lone Hill (Lower Pleistocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Qbsc

Enumerated Domain Value Definition: Basalt of Seldom Creek (Lower Pleistocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Qbcp

Enumerated Domain Value Definition: Basalt of Chaffee Point (Lower Pleistocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Qblc

Enumerated Domain Value Definition: Basalt of Lost Creek (Lower Pleistocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Qbal

Enumerated Domain Value Definition: Basaltic Andesite of Lost Peak (Lower Pleistocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Qbpp

Enumerated Domain Value Definition: Basalt of Pearce Point (Lower Pleistocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Qbar

Enumerated Domain Value Definition: Basaltic Andesite of Rye Spur (Lower Pleistocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Tpbla

Enumerated Domain Value Definition: Basalt of Lake Aphis (Upper Pliocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Tpbaf

Enumerated Domain Value Definition: Andesite of Freye Lake (Upper Pliocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Tpbhc

Enumerated Domain Value Definition: Basalt of Horse Creek (Middle Pliocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Tpbad

Enumerated Domain Value Definition: Basaltic Andesite of Dry Creek (Middle Pliocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Tpais

Enumerated Domain Value Definition: Andesite of Ichabod Spring (Middle Pliocene)

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Attribute:

Attribute Label: Name

Attribute Definition: The Name attribute represents the name of the unit of which the entity is a part. The name combines information on the lithology of the unit with a geographic feature located within or near the unit’s boundary, such as a mountain or a body of water. Detailed descriptions of the units found within the Lake of the Woods North USGS 7.5′ quadrangle are available in Open-File Report O-11-03 (Mertzman et al., 2011).

Attribute Definition Source: See Mertzman et al., 2011.

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: Alluvium

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011 for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Undifferentiated colluvium and alluvium

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Basaltic/basaltic andesite/andesite vent deposits

Enumerated Domain Value Definition: Poorly lithified to unconsolidated lapilli to ash-sized cinders, black to brown to red with lesser amounts of similarly colored lava spatter, bombs, and scoria. These deposits mark volcanic vents areas that are often scoria or cinder cones. Pleistocene in age. These areas should be considered sub-units of the units in which they are found, and samples found within areas of basaltic/basaltic andesite/andesite vent deposits are classified as part of the complimentary unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Andesite of Brown Mountain

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Andesite of Fourmile Creek

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Andesite of Pelican Butte

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Andesite of Whiteface Peak

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Basaltic Andesite of Long Creek Peak (Hill 6588)

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman

et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Basalt of Woodpecker Lake

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Basalt of Lone Hill

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Basalt of Seldom Creek

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Basalt of Chaffee Point

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Basalt of Lost Creek

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Basaltic Andesite of Lost Peak

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Basalt of Pearce Point

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Basaltic Andesite of Rye Spur

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Basalt of Lake Aphis

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Basaltic Andesite of Freye Lake

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Basalt of Horse Creek

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Basaltic Andesite of Dry Creek

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Andesite of Ichabod Spring

Enumerated Domain Value Definition: See Open-File Report O-11-03 (Mertzman et al., 2011) for a detailed description of this unit.

Enumerated Domain Value Definition Source: Open-File Report O-11-03 (Mertzman et al., 2011).

Attribute:

Attribute Label: Age_Geologic_Time_Scale

Attribute Definition: The Age_Geologic_Time_Scale represents the age of a unit in terms of the “Stage Age” (convention not completely followed, only Lower, Middle, and Upper are used as classes in this naming category) and “Series Epoch” classifiers of the 2007 International Stratigraphic Chart (International Commission on Stratigraphy, 2007) as defined by dates calculated by Gradstein et al. (2004). The attribute value was determined by a comparison of a unit’s dated age(s) to the stratigraphic age boundaries in the 2007 International Stratigraphic Chart (International Commission on Stratigraphy, 2007). A range of geologic time scale ages may be provided for a unit due to a range of ages calculated for one or more samples therein by K-Ar or 40Ar/39Ar dating methods. This attribute provides a low resolution representation of the age of a unit.

Attribute Definition Source: See Open-File Report O-11-03 (Mertzman et al., 2011), International Convention on Stratigraphy (2007), and Gradstein et al. (2004).

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: Holocene

Enumerated Domain Value Definition: Unknown Holocene (<0.0115 Ma).

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International Convention on Stratigraphy (2007), and Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Pleistocene to Holocene

Enumerated Domain Value Definition: Unknown Pleistocene to Holocene (<1.806 Ma).

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International Convention on Stratigraphy (2007), and Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Upper Pleistocene

Enumerated Domain Value Definition: 0.126 – 0.0115 million years ago (Ma)

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International Convention on Stratigraphy (2007), and Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Middle Pleistocene

Enumerated Domain Value Definition: 0.781 – 0.126 million years ago (Ma)

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International Convention on Stratigraphy (2007), and Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Lower to Middle Pleistocene

Enumerated Domain Value Definition: 1.806 – 0.126 million years ago (Ma)

Enumerated Domain:

Enumerated Domain Value: Lower Pleistocene

Enumerated Domain Value Definition: 1.806 – 0.781 million years ago (Ma)

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International Convention on Stratigraphy (2007), and Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International Convention on Stratigraphy (2007), and Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Upper Pliocene

Enumerated Domain Value Definition: 2.588 – 1.806 million years ago (Ma)

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International Convention on Stratigraphy (2007), and Open-File Report O-11-03 (Mertzman et al., 2011).

Enumerated Domain:

Enumerated Domain Value: Middle Pliocene

Enumerated Domain Value Definition: 3.600 – 2.588 million years ago (Ma)

Enumerated Domain Value Definition Source: Gradstein et al. (2004), International Convention on Stratigraphy (2007), and Open-File Report O-11-03 (Mertzman et al., 2011).

Attribute:

Attribute Label: Age_Ma

Attribute Definition: The Age_Ma attribute describes the absolute age or age-range of a unit in

millions of years as determined by the dating of collected rock samples with K-Ar or 40Ar/39Ar methods. The values are presented with the calculated ages and their error ranges. All units have been age-dated using either of the two aforementioned radiometric dating methods, except for the Qal (Alluvium), Qg (Undifferentiated colluvium and alluvium), and Qabm (Andesite of Brown Mountain) units. The Range Domain described below pertains to the radiometrically dated samples. The value for the Qal unit is “unknown Holocene (<0.0115 Ma);” the value for the Qg unit is “unknown Quaternary (<1.806 Ma);” the value for the Qabm unit is "un-dated upper Pleistocene (~0.075 to 0.020 Ma)." Each Qbv unit (sub-unit) is tentatively given the age of the unit of which it is considered part since age-dated samples typically did not come from areas of Qbv (except in the Qbalc unit [Basaltic Andesite of Long Creek Peak (Hill 6588)]); therefore, a question mark is displayed with each Qbv area's age values (except that of Qbalc) to imply its tentative nature.

Attribute Definition Source: See Mertzman et al. (2011).

Attribute Domain Values:

Range Domain:

Range Domain Minimum: <0.0115 Ma

Range Domain Maximum: 3.25 ± 0.05 Ma

Attribute Units of Measure: Millions of years (Ma)

Detailed Description:

Entity Type:

Entity Type Label: Unit Boundary

Entity Type Definition: A unit boundary is the same as a contact. It is the ground-surface (or its trace on the surface, if buried/concealed) boundary between two rock units. In this data set, the unit boundaries are polylines traced on the unit polygon boundaries (except on the boundaries that corresponded with the edges of the quadrangle and were not the true unit boundaries). The contacts have been approximately located. The unit boundaries are contained in the LOWNUnitBounds file.

Entity Type Definition Source: None

Attribute:

Attribute Label: Unconformity_YorN

Attribute Definition: This attribute indicates whether a contact is an unconformity or not. None of the contacts in the Lake of the Woods North quadrangle is classified as an unconformity.

Attribute Definition Source: None

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: N

Enumerated Domain Value Definition: A “N” indicates that this contact is not an unconformity. These are solid lines on the geologic map, representing an approximately located unit boundary/contact.

Enumerated Domain Value Definition Source: None

Enumerated Domain:

Enumerated Domain Value: Y

Enumerated Domain Value Definition: A “Y” indicates that the contact is an unconformity. There are no unconformities on the Lake of the Woods North

quadrangle geologic map.

Enumerated Domain Value Definition Source: None

Detailed Description:

Entity Type:

Entity Type Label: Sample

Entity Type Definition: A sample, with regard to this data set, is a field-collected rock specimen from an in situ outcrop (lava flows or vent deposits) – or in the case of the samples from the Qg area, a piece of float – located within the boundaries of the Lake of the Woods North USGS 7.5′ quadrangle (42122d2). The goal was to collect a representative suite of samples for each unit. A sample may have been apportioned for the following possible types of analysis: hand-sample analysis with possible use of a hand lens and other tools; heating to measure the loss on ignition (LOI); chemical analysis by X-ray fluorescence (XRF) spectroscopy (all samples); thin section analysis; age-dating by either K-Ar or 40Ar/39Ar methods. Samples can be displayed as point data.

In the LOWNSamples file, sample collection locations are indicated with either a black triangle or with a yellow square with a black outline. The black triangles represent samples for which there is available chemistry data in the attributes table. The yellow squares represent samples that have been age-dated by K-Ar or 40Ar/39Ar dating methods and also have chemistry data in the data table (attribute table).

Entity Type Definition Source: See Mertzman et al. (2011).

Attribute:

Attribute Label: Map_No

Attribute Definition: The Map_No is the map number. The map number is displayed on the geologic maps made using this dataset, such as the LOWNMap30x36.pdf discussed above. Map numbers were assigned sequentially to all of the samples after they were organized by age, formation, and silica content. The samples and their data were organized first by the formation, from oldest to youngest formation. Within each formation the data were further organized by placing age-dated samples before samples that were not age-dated. The age- dated samples for each formation were arranged by silica content, from lowest to highest silica content. Then the non-age-dated samples for each formation were arranged by silica content, from lowest to highest. After the data were organized, the map numbers were assigned sequentially down the data table from 1 to 110.

Attribute Definition Source: None

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 1

Range Domain Maximum: 114

Attribute:

Attribute Label: Sample_No

Attribute Definition: The Sample_No is the number or combination of numbers and letters that was assigned to a sample when it was collected in the field, or shortly thereafter. The letters, if present, indicate the initials of the person who collected the sample and the first two numbers (if present) usually represent the last two digits of the year in which the sample was collected. After the first two numbers (possibly with two letters, the naming scheme may vary for some samples) is a dash followed by a number that usually indicates a sample’s place in the order of collection for a particular year. For example, the eighty-sixth sample collected by Stanley Mertzman in 1992 has the sample number 92-86.

Attribute Definition Source: None

Attribute Domain Values:

Unpresentable Domain: The values of this attribute were created systematically (mostly), but they are not all numerical and there is no very easy way to describe the domain of these values without creating a sizeable list of the actual values. It is best to understand how the Sample_No attribute was assigned as discussed in the Attribute Definition above.

Attribute:

Attribute Label: KAr_Age_Ma

Attribute Definition: The KAr_Age_Ma is a sample’s absolute age in millions of years as determined by K-Ar or 40Ar/39Ar dating methods. Not all samples collected in the Lake of the Woods North 7.5′ quadrangle have been age-dated; a total of 14 samples collected from outcrops within this quadrangle have been age-dated. Also provided is the error range of the dated age of a sample.

Attribute Definition Source: Consult Mertzman et al. (2011).

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.21 ± 0.18

Range Domain Maximum: 2.78 ± 0.09

Attribute Units of Measure: Millions of years (Ma)

Attribute:

Attribute Label: Qtr_of_Qtr

Attribute Definition: The Qtr_of_Qtr attribute is the quarter-quarter section classifier of the Public Land Survey System (PLSS). This attribute describes in what quarter (NW, NE, SE, SW) of a quarter section of a section of a township a sample was collected. In this data set, all Township descriptors are according to the grid defined by the Willamette Meridian and Willamette Base Line of the PLSS.

Attribute Definition Source: Consult http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

and http://www.blm.gov/or/landrecords/legaldescrip.php

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: NW

Enumerated Domain Value Definition: The northwest quarter of a quarter section of a section of a township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Enumerated Domain:

Enumerated Domain Value: NE

Enumerated Domain Value Definition: The northeast quarter of a quarter section of a section of a township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Enumerated Domain:

Enumerated Domain Value: SE

Enumerated Domain Value Definition: The southeast quarter of a quarter section of a section of a township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Enumerated Domain:

Enumerated Domain Value: SW

Enumerated Domain Value Definition: The southwest quarter of a quarter section of a section of a township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Attribute:

Attribute Label: Qtr_of_Sec

Attribute Definition: The Qtr_of_Sec attribute is the quarter section classifier of the (PLSS). This attribute describes in what quarter section (NW, NE, SE, SW) of a section of a township a sample was collected. In this data set, all Township descriptors are according to the grid defined by the Willamette Meridian and Willamette Base Line of the PLSS.

Attribute Definition Source: Consult http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

and http://www.blm.gov/or/landrecords/legaldescrip.php

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: NW

Enumerated Domain Value Definition: The northwest quarter section of a section of a township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Enumerated Domain:

Enumerated Domain Value: NE

Enumerated Domain Value Definition: The northeast quarter section of a section of a township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Enumerated Domain:

Enumerated Domain Value: SE

Enumerated Domain Value Definition: The southeast quarter section of a section of a township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Enumerated Domain:

Enumerated Domain Value: SW

Enumerated Domain Value Definition: The southwest quarter section of a section of a township.

Enumerated Domain Value Definition Source: Consult

http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

Attribute:

Attribute Label: Sec

Attribute Definition: The Sec is the Section of the Township (according to the PLSS grid) in which the sample was collected. The Section is “a one-square-mile block of land, containing 640 acres, or approximately one thirty-sixth of a township. Due to the curvature of the Earth, sections may occasionally be slightly smaller than one square mile.” In this data set, all Township descriptors are according to the grid defined by the Willamette Meridian and Willamette Base Line of the PLSS.

Attribute Definition Source: Consult http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

and http://www.blm.gov/or/landrecords/legaldescrip.php

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 1

Range Domain Maximum: 36

Attribute:

Attribute Label: T_S

Attribute Definition: The T_S (Township_South) is the value of the horizontal row of townships in the PLSS grid (Willamette Meridian and Willamette Base Line for all samples in this data set) in which the sample was collected. The “S” (South) descriptor indicates that the township rows that pertain to this data set are south of the Willamette Base Line of the PLSS. When combined with the R_E (Range) attribute value, this information provides the specific ~36 square mile Township in the Willamette Meridian and Base Line defined grid of the PLSS in which the sample was collected. The other more specific PLSS descriptor attributes were described and discussed above.

Attribute Definition Source: Consult http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

and http://www.blm.gov/or/landrecords/legaldescrip.php

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 35

Range Domain Maximum: 37

Attribute:

Attribute Label: R_E

Attribute Definition: The R_E (Range_East) is the value of the vertical column of townships in the PLSS grid (Willamette Meridian and Willamette Base Line for this data set) in which the

sample was collected. The “E” (East) descriptor indicates that the township columns that pertain to this data set are to the east of the Willamette Meridian. When combined with the

T_S attribute value, this information provides the specific ~36 square mile Township in the Willamette Meridian and Base Line defined grid of the PLSS in which the sample was collected. The other more specific PLSS descriptor attributes were described above.

Attribute Definition Source: Consult http://www-atlas.usgs.gov/articles/boundaries/a_plss.html

and http://www.blm.gov/or/landrecords/legaldescrip.php

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 5

Range Domain Maximum: 6

Attribute:

Attribute Label: UTM_E_m

Attribute Definition: This is the easting value in meters of a sample’s collection location according to the NAD 1927 UTM Zone 10 projection system. This value was determined with the MapInfo Professional version 7.0 Coordinate Extractor extension. In cases in which the UTM coordinates were already known, the coordinate extractor extracted these same coordinates. Please note that the precision indicated by this value does not represent the precision with which a sample’s location was determined. Instead, it represents the precision of the MapInfo v.7.0 Coordinate Extractor extension’s results as determined for carefully digitized sample location points (from original paper maps to the drg of the quadrangle, except where coordinates were provided and already rounded to the nearest 10 meters).

Attribute Definition Source: Consult

http://erg.usgs.gov/isb/pubs/factsheets/fs07701.html

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 561,771.72

Range Domain Maximum: 571,364.18

Attribute Units of Measure: meters

Attribute:

Attribute Label: UTM_N_m

Attribute Definition: This is the northing value in meters of a sample’s collection location according to the NAD 1927 UTM Zone 10 projection system. This value was determined with the MapInfo Professional version 7.0 Coordinate Extractor extension. In cases in which the UTM coordinates were already known, the coordinate extractor extracted these same coordinates. Please note that the precision indicated by this value does not represent the precision with which a sample’s location was determined. Instead, it represents the precision of the MapInfo v.7.0 Coordinate Extractor extension’s results as determined for carefully digitized sample location points (from original paper maps to the drg of the quadrangle, except where coordinates were provided and already rounded to the nearest 10 meters).

Attribute Definition Source: Consult http://erg.usgs.gov/isb/pubs/factsheets/fs07701.html

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 4,691,862.12

Range Domain Maximum: 4,704,337.92

Attribute Units of Measure: meters

Attribute:

Attribute Label: Unit

Attribute Definition: This is the unit, indicated by the unit’s symbol, to which a collected rock sample belongs. Samples collected in an area of Qg are from pieces of float found on the undifferentiated colluvium and alluvium deposits.

Attribute Definition Source: See Mertzman et al. (2011).

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: Tpbad

Enumerated Domain Value Definition: Basaltic Andesite of Dry Creek (Middle Pliocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Enumerated Domain:

Enumerated Domain Value: Tpbhc

Enumerated Domain Value Definition: Basalt of Horse Creek (Middle Pliocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Enumerated Domain:

Enumerated Domain Value: Tpbaf

Enumerated Domain Value Definition: Basaltic Andesite of Freye Lake (Upper Pliocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Enumerated Domain:

Enumerated Domain Value: Tpbla

Enumerated Domain Value Definition: Basalt of Lake Aphis (Upper Pliocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011). Enumerated Domain:

Enumerated Domain Value: Qbar

Enumerated Domain Value Definition: Basaltic Andesite of Rye Spur (Lower Pleistocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Enumerated Domain:

Enumerated Domain Value: Qawp

Enumerated Domain Value Definition: Andesite of Whiteface Peak (Lower to Middle Pleistocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Enumerated Domain:

Enumerated Domain Value: Qbpp

Enumerated Domain Value Definition: Basalt of Pearce Point (Lower Pleistocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Enumerated Domain:

Enumerated Domain Value: Qbwl

Enumerated Domain Value Definition: Basalt of Woodpecker Lake (Lower Pleistocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Enumerated Domain:

Enumerated Domain Value: Qblc

Enumerated Domain Value Definition: Basalt of Lost Creek (Lower Pleistocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Enumerated Domain:

Enumerated Domain Value: Qbcp

Enumerated Domain Value Definition: Basalt of Chaffee Point (Lower Pleistocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Enumerated Domain:

Enumerated Domain Value: Qbsc

Enumerated Domain Value Definition: Basalt of Seldom Creek (Lower Pleistocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Enumerated Domain:

Enumerated Domain Value: Qblh

Enumerated Domain Value Definition: Basalt of Lone Hill (Lower Pleistocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Enumerated Domain:

Enumerated Domain Value: Qbalc

Enumerated Domain Value Definition: Basaltic Andesite of Long Creek Peak (Lower Pleistocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Enumerated Domain:

Enumerated Domain Value: Qapb

Enumerated Domain Value Definition: Andesite of Pelican Butte (Middle Pleistocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Enumerated Domain:

Enumerated Domain Value: Qafc

Enumerated Domain Value Definition: Andesite of Fourmile Creek (Middle to Upper Pleistocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Enumerated Domain:

Enumerated Domain Value: Qabm

Enumerated Domain Value Definition: Andesite of Brown Brown Mountain (Upper Pleistocene to Holocene)

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Enumerated Domain:

Enumerated Domain Value: Qg

Enumerated Domain Value Definition: Undifferentiated colluvium and alluvium (Pleistocene to Holocene). Note that samples from these areas are likely from

float found within the undifferentiated colluvium and alluvium but were originally from other units on the map and disrupted by glacial or other

erosional processes.

Enumerated Domain Value Definition Source: See Mertzman et al. (2011).

Attribute:

Attribute Label: Lith

Attribute Definition: The Lith attribute is an abbreviation of the lithology of the sample according to the total alkali (Na2O + K2O [weight%(wt%)]) versus silica (SiO2 wt%) classification (TAS classification) for volcanic rocks of Le Maitre (2002). The chemistry of the sample was determined by X-ray fluorescence (XRF) spectroscopy. Macroscopic characteristics of the various lithologies are not discussed here.

Attribute Definition Source: See Mertzman et al. (2011) and Le Maitre (2002)

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: B

Enumerated Domain Value Definition: Basalt: a volcanic rock with a silica content of 45-52 wt% and less than 5 wt% total alkali (Na2O + K2O wt%) content.

Enumerated Domain Value Definition Source: See Mertzman et al. (2011), Le Maitre (2002), and http://www.geol.lsu.edu/henry/Geology3041/

lectures/02IgneousClassify/IUGS-IgneousClassFlowChart.htm

Enumerated Domain:

Enumerated Domain Value: BA

Enumerated Domain Value Definition: Basaltic andesite: a volcanic rock with 52- 57 wt% silica content and a total alkali content of less than 5 wt% at 52 wt% SiO2 and less than 5.9 wt% at 57 wt% SiO2. Between 52 and 57 wt% SiO2, the upper total alkali boundary increases linearly from 5 to 5.9 wt%.

Enumerated Domain Value Definition Source: See Mertzman et al. (2011), Le Maitre (2002), and http://www.geol.lsu.edu/henry/Geology3041/

lectures/02IgneousClassify/IUGS-IgneousClassFlowChart.htm.

Enumerated Domain:

Enumerated Domain Value: A

Enumerated Domain Value Definition: Andesite: a volcanic rock with a silica content of 57-63 wt% and a total alkali content of less than 5.9 wt% at 57

wt% SiO2 and less than 7 wt% at 63 wt% SiO2. Between 57 and 63 wt% SiO2, the upper total alkali boundary increases linearly from 5.9 wt% to 7 wt%.

Enumerated Domain Value Definition Source: See Mertzman et al. (2011), Le Maitre (2002), and http://www.geol.lsu.edu/henry/Geology3041/

lectures/02IgneousClassify/IUGS-IgneousClassFlowChart.htm

Enumerated Domain:

Enumerated Domain Value: BTrA

Enumerated Domain Value Definition: Basaltic trachyandesite: a volcanic rock with a silica content of 59.4-57.0 wt% and a total alkali content higher than basalts, trachybasalts, and basaltic andesites in that same silica range. See a TAS plot in Figure 4 of Mertzman et al. (2011) or the other cited references.

Enumerated Domain Value Definition Source: See Mertzman et al. (2011), Le Maitre (2002), and http://www.geol.lsu.edu/henry/Geology3041/

lectures/02IgneousClassify/IUGS-IgneousClassFlowChart.htm

Enumerated Domain:

Enumerated Domain Value: BA/BTrA

Enumerated Domain Value Definition: A rock with a total alkali and silica composition that plots right on the boundary between basaltic andesite and

basaltic trachyandesite in a TAS plot.

Enumerated Domain Value Definition Source: See Mertzman et al. (2011), Le Maitre (2002), and http://www.geol.lsu.edu/henry/Geology3041/

lectures/02IgneousClassify/IUGS-IgneousClassFlowChart.htm

Attribute:

Attribute Label: SiO2_%

Attribute Definition: The weight percent (wt%) of silica (SiO2) in the sample as measured by XRF spectroscopy.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 46.87

Range Domain Maximum: 60.71 Attribute Units of Measure: weight percent (wt%)

Attribute:

Attribute Label: TiO2_%

Attribute Definition: The weight percent (wt%) of titania (TiO2) in the sample as measured by XRF spectroscopy.

Attribute Definition Source: See http://fandm.edu/x7985.xml Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.62

Range Domain Maximum: 1.27

Attribute Units of Measure: weight percent (wt%)

Attribute:

Attribute Label: Al2O3_%

Attribute Definition: The weight percent (wt%) of alumina (Al2O3) in the sample as measured by XRF spectroscopy.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 15.37

Range Domain Maximum: 18.87

Attribute Units of Measure: weight percent (wt%)

Attribute:

Attribute Label: Fe2O3_%

Attribute Definition: The weight percent (wt%) of iron(III) oxide (Fe2O3) in the sample as calculated using results measured by XRF spectroscopy and Iron Titration.

Attribute Definition Source: See http://fandm.edu/x7991.xml and http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.39

Range Domain Maximum: 10.1955

Attribute Units of Measure: weight percent (wt%)

Attribute:

Attribute Label: FeO_%

Attribute Definition: The weight percent (wt%) of iron(II) oxide (FeO) in the sample determined by Iron Titration.

Attribute Definition Source: See http://fandm.edu/x7991.xml and http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.13

Range Domain Maximum: 7.79

Attribute Units of Measure: weight percent (wt%)

Attribute:

Attribute Label: MnO_%

Attribute Definition: The weight percent (wt%) of manganese(II) oxide (MnO) in the sample as measured by XRF spectroscopy.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.08

Range Domain Maximum: 0.17

Attribute Units of Measure: weight percent (wt%)

Attribute:

Attribute Label: MgO_%

Attribute Definition: The weight percent (wt%) of magnesia (MgO) in the sample as measured by XRF spectroscopy.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 3.04

Range Domain Maximum: 10.61

Attribute Units of Measure: weight percent (wt%)

Attribute:

Attribute Label: CaO_%

Attribute Definition: The weight percent (wt%) of calcium oxide (CaO) in the sample as measured by XRF spectroscopy.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 5.95

Range Domain Maximum: 11.43

Attribute Units of Measure: weight percent (wt%)

Attribute:

Attribute Label: Na2O_%

Attribute Definition: The weight percent (wt%) of sodium oxide (Na2O) in the sample as measured by XRF spectroscopy.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 2.27

Range Domain Maximum: 4.35

Attribute Units of Measure: weight percent (wt%)

Attribute:

Attribute Label: K2O_%

Attribute Definition: The weight percent (wt%) of potassium oxide

(K2O) in the sample as measured by XRF spectroscopy.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.1

Range Domain Maximum: 1.53

Attribute Units of Measure: weight percent (wt%)

Attribute:

Attribute Label: P2O5_%

Attribute Definition: The weight percent (wt%) of phosphorus pentoxide

(P2O5) in the sample as measured by XRF spectroscopy.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.06

Range Domain Maximum: 0.5

Attribute Units of Measure: weight percent (wt%)

Attribute:

Attribute Label: LOI_%

Attribute Definition: True Loss on Ignition: the amount of weight lost (weight percent (wt%)) by the sample after heating to between 900şC and 950şC for one hour added to a value that accounts for the changes in weight resulting from the oxidation of ferrous iron.

Attribute Definition Source: See http://fandm.edu/x7991.xml and http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.18

Range Domain Maximum: 5.72

Attribute Units of Measure: weight percent (wt%)

Attribute:

Attribute Label: Total_%

Attribute Definition: The total weight percent (wt%) is the sum of the weight percent values for SiO2, TiO2, Al2O3, Fe2O3, FeO, MnO, MgO, CaO, Na2O, K2O, P2O5, and LOI.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 99.06

Range Domain Maximum: 100.84

Attribute Units of Measure: weight percent (wt%)

Attribute:

Attribute Label: Fe2O3T_%

Attribute Definition: The iron(III) iron content (wt%) measured by XRF spectroscopy. This is not the true amount of iron(III) iron originally present in the rock sample because it also accounts for iron(II) iron that was oxidized to iron(III) iron during the preparation for XRF. The Fe2O3_% value described above is the true amount of iron(III) iron present in the rock sample.

Attribute Definition Source: See http://fandm.edu/x7991.xml and http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 5.73

Range Domain Maximum: 11.14

Attribute Units of Measure: weight percent (wt%)

Attribute:

Attribute Label: Rb_ppm

Attribute Definition: The amount (in parts per million [ppm]) of rubidium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Rb value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 2.8

Range Domain Maximum: 30.4

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Sr_ppm

Attribute Definition: The amount (in parts per million [ppm]) of strontium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Sr value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 390

Range Domain Maximum: 1113

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Y_ppm

Attribute Definition: The amount (in parts per million [ppm]) of yttrium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Y value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 10.8

Range Domain Maximum: 26.2

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Zr_ppm

Attribute Definition: The amount (in parts per million [ppm]) of zirconium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Zr value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 35

Range Domain Maximum: 155

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: V_ppm

Attribute Definition: The amount (in parts per million [ppm]) of vanadium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no V value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 111

Range Domain Maximum: 252

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Ni_ppm

Attribute Definition: The amount (in parts per million [ppm]) of nickel present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Ni value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 6

Range Domain Maximum: 251

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Cr_ppm

Attribute Definition: The amount (in parts per million [ppm]) of chromium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Cr value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 21

Range Domain Maximum: 605

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Nb_ppm

Attribute Definition: The amount (in parts per million [ppm]) of niobium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Nb value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 1.2

Range Domain Maximum: 8.6

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Ga_ppm

Attribute Definition: The amount (in parts per million [ppm]) of gallium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Ga value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 13.6

Range Domain Maximum: 21.7

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Cu_ppm

Attribute Definition: The amount (in parts per million [ppm]) of copper present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Cu value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 20 Range Domain Maximum: 117

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Zn_ppm

Attribute Definition: The amount (in parts per million [ppm]) of zinc present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Zn value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 54

Range Domain Maximum: 87

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Co_ppm

Attribute Definition: The amount (in parts per million [ppm]) of cobalt present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Co value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 14

Range Domain Maximum: 44

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Ba_ppm

Attribute Definition: The amount (in parts per million [ppm]) of barium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Ba value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 64

Range Domain Maximum: 541

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: La_ppm

Attribute Definition: The amount (in parts per million [ppm]) of lanthanum present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no La value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 3.4

Range Domain Maximum: 21

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Ce_ppm

Attribute Definition: The amount (in parts per million [ppm]) of cesium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Ce value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 8.2

Range Domain Maximum: 47.7

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: U_ppm

Attribute Definition: The amount (in parts per million [ppm]) of uranium present in the sample as measured by XRF spectroscopy. A “<0.5” has been placed where the U in a sample was below the limit of the XRF spectrometer’s sensitivity. A “--" has been placed where there

is no U value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.3

Range Domain Maximum: 1.7

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Th_ppm

Attribute Definition: The amount (in parts per million [ppm]) of thorium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Th value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.2

Range Domain Maximum: 5

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Sc_ppm

Attribute Definition: The amount (in parts per million [ppm]) of scandium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Sc value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 13

Range Domain Maximum: 37

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Pb_ppm

Attribute Definition: The amount (in parts per million [ppm]) of lead present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Pb value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 1

Range Domain Maximum: 14

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Yb_ppm

Attribute Definition: The amount (in parts per million [ppm]) of ytterbium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Yb value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.7

Range Domain Maximum: 2.4

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Be_ppm

Attribute Definition: The amount (in parts per million [ppm]) of beryllium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Be value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.8

Range Domain Maximum: 2.2

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Hf_ppm

Attribute Definition: The amount (in parts per million [ppm]) of hafnium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Hf value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 1.4

Range Domain Maximum: 2.7

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Ta_ppm

Attribute Definition: The amount (in parts per million [ppm]) of tantalum present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Ta value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.3

Range Domain Maximum: 0.6

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Nd_ppm

Attribute Definition: The amount (in parts per million [ppm]) of neodymium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Nd value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 7

Range Domain Maximum: 23

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Sm_ppm

Attribute Definition: The amount (in parts per million [ppm]) of samarium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Sm value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 2.1

Range Domain Maximum: 4.3

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Eu_ppm

Attribute Definition: The amount (in parts per million [ppm]) of europium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Eu value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.83

Range Domain Maximum: 1.37

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Tb_ppm

Attribute Definition: The amount (in parts per million [ppm]) of terbium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Tb value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.4

Range Domain Maximum: 0.6

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: Lu_ppm

Attribute Definition: The amount (in parts per million [ppm]) of lutetium present in the sample as measured by XRF spectroscopy. A “--" has been placed where there is no Lu value for a sample.

Attribute Definition Source: See http://fandm.edu/x7985.xml

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 0.17

Range Domain Maximum: 0.38

Attribute Units of Measure: parts per million (ppm)

Attribute:

Attribute Label: DatedOrNot

Attribute Definition: This attribute is only present in the ESRI Shapefile formatted Lake of the Woods North samples file (LOWNSamples_point.shp). This attribute indicates if a sample

was age-dated or not.

Attribute Definition Source: None

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: Y

Enumerated Domain Value Definition: The Y stands for “Yes,” meaning that this rock sample has been age-dated by K-Ar or 40Ar/39Ar dating methods.

Enumerated Domain Value Definition Source: None

Enumerated Domain:

Enumerated Domain Value: N

Enumerated Domain Value Definition: The N stands for “No,” meaning that this rock sample has not been age-dated with radiometric dating methods.

Enumerated Domain Value Definition Source: None

Detailed Description:

Entity Type:

Entity Type Label: Fault

Entity Type Definition: A fault is a planar fracture or area of fractured rock where there is relative movement of large bodies of rock. There are several prominent faults in the Lake of the

WoodsNorth USGS 7.5’ Quadrangle. These faults are normal faults. The dashed lines with hatch marks/tick marks/bars represent the inferred location of the faults where the fault traces are buried/concealed. The solid lines with hatch marks/ tick marks/ bars represents the approximate location of the fault traces. The hatch marks/tick marks/bars are on the down-dropped block (hanging wall).

Entity Type Definition Source: See Mertzman et al. (2011),

http://volcanoes.usgs.gov/Products/Pglossary/fault.html ,

http://www.ucmp.berkeley.edu/glossary/glossary_2.html ,

http://earthquake.usgs.gov/learning/glossary.php?term=fault%20plane ,

http://www2.nature.nps.gov/geology/usgsnps/deform/ghangft.html and http://en.wikipedia.org/wiki/Fault_%28geology%29

Attribute:

Attribute Label: Appr_or_Conc

Attribute Definition: This attribute indicates if the fault trace is present on the earth’s surface or if the fault is buried, such as by Quaternary-aged alluvium.

Attribute Definition Source: None

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: Approximate

Enumerated Domain Value Definition: This indicates that the fault trace is present on the earth’s surface and that its location is a close approximation. This portion of the fault is displayed on the geologic map as a hatch-marked solid line with the bars/hatches on the down-dropped block (hanging wall).

Enumerated Domain Value Definition Source: None

Enumerated Domain:

Enumerated Domain Value: Concealed

Enumerated Domain Value Definition: This indicates that the fault to the trace is not present on the earth's surface, but is assumed to be the buried continuation of a fault observed on the surface. The concealed fault may be covered by Quaternary alluvium or other material. The locations of the concealed portions of faults are inferred based on locally observable fault traces. This portion of the fault is displayed on the geologic map as a hatch-

marked dash line with the bars/hatches on the down-dropped block (hanging wall).

Enumerated Domain Value Definition Source: None

Attribute:

Attribute Label: Type_of_Fault

Attribute Definition: This attribute indicates the type of fault present.

Attribute Definition Source: None

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: Normal

Enumerated Domain Value Definition: A normal fault is a plane at which the hanging wall moves down relative to the footwall (in other words, one body of rock slides down along the fault relative to the other body of rock in the direction of the fault planes dip). The fault plane slopes (dips) downward in the direction of the hanging-wall.

Enumerated Domain Value Definition Source: Consult

http://eqseis.geosc.psu.edu/~cammon/HTML/

Classes/IntroQuakes/Notes/faults.html

Attribute:

Attribute Label: Notes

Attribute Definition: These are notes with important details about the fault, indicating the location of the down-dropped block/hanging wall relative to the fault.

Attribute Definition Source: None

Attribute Domain Values:

Enumerated Domain:

Enumerated Domain Value: Down-dropped block is to the east of the fault.

Enumerated Domain Value Definition: This means what it says. The hanging-wall is the down-dropped body of rock, which is to the east of the fault (on the side where the tick marks are on the map). The body of rock to the east of the fault is moving down along the fault relative to the body of rock to the west (the footwall). When the down-dropped block is to the east in a normal fault, this also indicates that the fault dips to the east.

Enumerated Domain Value Definition Source: Please see Mertzman et al. (2011) and http://eqseis.geosc.psu.edu/~cammon/HTML/

Classes/IntroQuakes/Notes/faults.html

Detailed Description:

Entity Type:

Entity Type Label: Volcanic Center

Entity Type Definition: A volcanic center is a source of volcanic rocks. In other words, it is a location where subterranean magma has erupted onto the surface. Observations made in the field helped to locate volcanic centers where there were no vent deposits. In this data set, the volcanic centers are contained in the LOWNVolcCenters file and are point data displayed as red triangles with a black outline.

Entity Type Definition Source: None

Attribute:

Attribute Label: UTM_E_m

Attribute Definition: This is the easting value in meters of a volcanic center's location according to the NAD 1927 UTM Zone 10 projection system. This value was determined with the MapInfo Professional version 7.0 Coordinate Extractor tool. The precision of this value does not represent that with which it was determined, but is the precision provided by MapInfo Professional v.7.0's Coordinate Extractor extension for the points manually digitized to the georeferenced quadrangle drg.

Attribute Definition Source: None

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 562,501.85

Range Domain Maximum: 569,813.27

Attribute Units of Measure: meters

Attribute:

Attribute Label: UTM_N_m

Attribute Definition: This is the easting value in meters of a volcanic center's location according to the NAD 1927 UTM Zone 10 projection system. This value was determined with the MapInfo Professional version 7.0 Coordinate Extractor tool. The precision of this value does not represent that with which it was determined, but is the precision provided by MapInfo Professional v.7.0's Coordinate Extractor extension for the points manually digitized to the georeferenced quadrangle drg.

Attribute Definition Source: None

Attribute Domain Values:

Range Domain:

Range Domain Minimum: 4,693,596.49

Range Domain Maximum: 4,704,735.56

Attribute Units of Measure: meters

Distribution Information

Metadata Reference Information

Metadata Date: 20110109

Metadata Contact:

Contact Information:

Contact Person Primary:

Contact Person: Isaac Weaver

Contact Position: Research Assistant

Contact Address:

Address Type: mailing and physical address

Address: Isaac Weaver, Franklin and Marshall College, Department of Earth and Environment, PO Box 3003

City: Lancaster

State or Province: Pennsylvania

Postal Code: 17604

Contact Voice Telephone: Unavailable

Contact Electronic Mail Address: iweaver@fandm.edu

Metadata Standard Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata Standard Version: Version 2 – 1998