Database of the Geologic Map of North America- Adapted from the Map by J.C. Reed, Jr. and others (2005)
Metadata:
- Identification_Information:
-
- Citation:
-
- Citation_Information:
-
- Originator: Garrity, C.P.
- Originator: Soller, D.R.
- Publication_Date: 2009
- Publication_Time: Unknown
- Title:
-
Database of the Geologic Map of North America- Adapted from the Map by J.C. Reed, Jr. and others (2005)
- Edition: 1.0
- Geospatial_Data_Presentation_Form: vector digital data
- Series_Information:
-
- Series_Name: Data Series
- Issue_Identification: 424
- Publication_Information:
-
- Publication_Place: Reston, VA
- Publisher: U.S. Geological Survey
- Online_Linkage: <https://pubs.usgs.gov/ds/424>
- Description:
-
- Abstract:
-
This map layer contains geologic unit boundaries for the area depicted in the Geologic Map of North America, published by the Geological Society of America in 2005 (Reed et. al, 2005). Digital data were compiled from source data at a scale of 1:5,000,000 and are not intended to be used at a larger (greater detail) scale.
- Purpose:
-
The release of this database will allow the general public, academia, and earth science professionals to view, evaluate and manipulate geologic data on a continental scale. It is hoped that use of this data, either by itself or in relation to other data sets, may lead to new interpretations of the geology of North America.
- Supplemental_Information:
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The comprehensive list of contributors to the Geologic Map of North America (Reed and others, 2005) is available on request from Documents Secretary, Geological Society of America, P.O. Box 9140, Boulder, CO 80301-9140, USA, editing@geosociety.org, or at <ftp://rock.geosociety.org/pub/reposit/2005/2005019.pdf>.
Users who wish to display the geologic map symbolization and color palettes similar to those used in the printed version of the GMNA are encouraged to open the map document (GMNA.mxd) in ArcMap. All map symbology was created to be used at a scale of 1:5,000,000. The following fonts are used as character markersets in the map document:
- Arial MT (ARIAL.TTF)
- Georgia (GEORGIA.TTF)
- ESRI Caves 2 (ESRI_376.TTF)
- ESRI Default Marker (ESRI_11.TTF)
- ESRI Enviro Hazard Sites (ESRI_802.TTF)
- ESRI Geology USGS 95-525 (ESRI_400.TTF)
- ESRI Geometric Symbols (ESRI_3.TTF)
- ESRI Oil, Gas, & Water (ESRI_4.TTF)
- ESRI Pipeline US 1 (ESRI_161.TTF)
- ESRI Telecom (ESRI_160.TTF)
- Time_Period_of_Content:
-
- Time_Period_Information:
-
- Single_Date/Time:
-
- Calendar_Date: 20080115
- Time_of_Day: unknown
- Currentness_Reference: publication date
- Status:
-
- Progress: Planned
- Maintenance_and_Update_Frequency: As needed
- Spatial_Domain:
-
- Bounding_Coordinates:
-
- West_Bounding_Coordinate: -180.000000
- East_Bounding_Coordinate: 180.000000
- North_Bounding_Coordinate: 90.000000
- South_Bounding_Coordinate: 5.676566
- Keywords:
-
- Theme:
-
- Theme_Keyword_Thesaurus: ISO 19115 Topic Category
- Theme_Keyword: Geoscientific Information
- Theme:
-
- Theme_Keyword_Thesaurus: None
- Theme_Keyword: Geologic Map of North America
- Theme_Keyword: GMNA
- Theme_Keyword: Geologic Map
- Theme_Keyword: Geology
- Place:
-
- Place_Keyword_Thesaurus: None
- Place_Keyword: North America
- Place_Keyword: United States
- Place_Keyword: Canada
- Place_Keyword: Alabama
- Place_Keyword: Alaska
- Place_Keyword: Arizona
- Place_Keyword: Arkansas
- Place_Keyword: California
- Place_Keyword: Colorado
- Place_Keyword: Connecticut
- Place_Keyword: Delaware
- Place_Keyword: District of Columbia
- Place_Keyword: Florida
- Place_Keyword: Georgia
- Place_Keyword: Hawaii
- Place_Keyword: Idaho
- Place_Keyword: Illinois
- Place_Keyword: Indiana
- Place_Keyword: Iowa
- Place_Keyword: Kansas
- Place_Keyword: Kentucky
- Place_Keyword: Louisiana
- Place_Keyword: Maine
- Place_Keyword: Maryland
- Place_Keyword: Massachusetts
- Place_Keyword: Michigan
- Place_Keyword: Minnesota
- Place_Keyword: Mississippi
- Place_Keyword: Missouri
- Place_Keyword: Montana
- Place_Keyword: Nebraska
- Place_Keyword: Nevada
- Place_Keyword: New Hampshire
- Place_Keyword: New Jersey
- Place_Keyword: New Mexico
- Place_Keyword: New York
- Place_Keyword: North Carolina
- Place_Keyword: North Dakota
- Place_Keyword: Ohio
- Place_Keyword: Oklahoma
- Place_Keyword: Oregon
- Place_Keyword: Pennsylvania
- Place_Keyword: Rhode Island
- Place_Keyword: South Carolina
- Place_Keyword: South Dakota
- Place_Keyword: Tennessee
- Place_Keyword: Texas
- Place_Keyword: Utah
- Place_Keyword: Vermont
- Place_Keyword: Virginia
- Place_Keyword: Washington
- Place_Keyword: West Virginia
- Place_Keyword: Wisconsin
- Place_Keyword: Wyoming
- Place_Keyword: Puerto Rico
- Place_Keyword: Virgin Islands
- Place_Keyword: U.S. Virgin Islands
- Place_Keyword: Mexico
- Place_Keyword: Central America
- Place_Keyword: South America
- Access_Constraints: None
- Use_Constraints:
-
This digital publication was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data published in this Data Series have been used by the USGS, no warranty, expressed or implied, is made by the U.S. Geological Survey as to the accuracy of the data and related materials and/or the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of this data, software, or related materials. Graphical map depictions are intended to be used within the map scale limits applicable to the source data. Although software enables the user to view data at various scales, the user is cautioned to refer to the source documentation for the appropriate map scale limitations.
- Point_of_Contact:
-
- Contact_Information:
-
- Contact_Person_Primary:
-
- Contact_Person: David Soller
- Contact_Organization: U.S. Geological Survey
- Contact_Position: Project Chief, National Geologic Map Database
- Contact_Address:
-
- Address_Type: physical address
- Address: MS 926-A National Center
- City: Reston
- State_or_Province: VA
- Postal_Code: 20192
- Country: USA
- Contact_Voice_Telephone: 703-648-6907
- Contact_TDD/TTY_Telephone: 703-648-6907
- Contact_Facsimile_Telephone: 703-648-6977
- Contact_Electronic_Mail_Address: drsoller@usgs.gov
- Hours_of_Service: 9:00AM - 6:00PM
- Contact_Instructions: Preferred contact method is electronic mail.
- Security_Information:
-
- Security_Classification_System: None
- Security_Classification: Unclassified
- Security_Handling_Description: None
- Native_Data_Set_Environment:
-
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.2.6.1500
- Cross_Reference:
-
- Citation_Information:
-
- Originator: Reed, J.C. Jr.
- Originator: Wheeler, J.O.
- Originator: Tucholke, J.E.
- Publication_Date: 2005
- Publication_Time: Unknown
- Title: Geologic Map of North America
- Edition:
-
Geological Society of America, DNAG Continent-Scale Map 001. Scale: 1:5,000,000
- Geospatial_Data_Presentation_Form: map
- Other_Citation_Details:
-
3 sheets (North, South, and Legend), approximately 74 x 40 inches.
- Online_Linkage:
-
<http://rock.geosociety.org/bookstore/default.asp?oID=0&catID=12&pID=CSM001R>
- Online_Linkage: <ftp://rock.geosociety.org/pub/reposit/2005/2005019.pdf>
- Data_Quality_Information:
-
- Attribute_Accuracy:
-
- Attribute_Accuracy_Report:
-
Attribute accuracy was tested by manual comparison of the source with hard copy printouts and/or symbolized display of the digital geologic data on an interactive computer graphic system. In addition, attributes were compared to a master set of valid geologic unit attributes.
- Logical_Consistency_Report:
-
Topological accuracy was tested using topology validation tools via ArcGIS 9.2. Specific errors that were checked included: Polygon overlaps and gaps, coincident contact lines and geologic unit borders, self overlapping lines and superfluous pseudo nodes. No duplicate features exist nor duplicate points in a data string. Intersecting lines are separated into individual line segments at the point of intersection. Feature classes in the geodatabase are topologically clean.
- Completeness_Report:
-
Data set complete. No data was intentionally omitted from the hard copy source map.
- Positional_Accuracy:
-
- Horizontal_Positional_Accuracy:
-
- Horizontal_Positional_Accuracy_Report:
-
Unsystematic registration errors at latitude-longitude intersections were observed throughout the printed version of the GMNA when overlain by computer generated graticules, particularly near the polar regions of the map. The amount of offset varied throughout the map, with a maximum offset estimated at about 4 km in certain high latitude areas.
- Quantitative_Horizontal_Positional_Accuracy_Assessment:
-
- Horizontal_Positional_Accuracy_Explanation:
-
It is likely that offset was introduced in the numerous iterations (and numerous technological changes in cartographic production) of the GMNA over its twenty year history of compilation.
- Vertical_Positional_Accuracy:
-
- Vertical_Positional_Accuracy_Report: Not applicable.
- Lineage:
-
- Source_Information:
-
- Source_Citation:
-
- Citation_Information:
-
- Originator: Reed, J.C. Jr.
- Originator: Wheeler, J.O.
- Originator: Tucholke, B.E.
- Publication_Date: 2005
- Publication_Time: Unknown
- Title: Geologic Map of North America
- Edition:
-
Decade of North American Geology Continental Scale Map 001. Scale: 1:5,000,000
- Geospatial_Data_Presentation_Form: map
- Other_Citation_Details:
-
3 sheets (North, South, and Legend), approximately 74 x 40 inches.
- Online_Linkage:
-
<http://rock.geosociety.org/bookstore/default.asp?oID=0&catID=12&pID=CSM001R>
- Online_Linkage: <ftp://rock.geosociety.org/pub/reposit/2005/2005019.pdf>
- Source_Scale_Denominator: 5,000,000
- Type_of_Source_Media: paper
- Source_Time_Period_of_Content:
-
- Time_Period_Information:
-
- Single_Date/Time:
-
- Calendar_Date: 2005
- Time_of_Day: unknown
- Source_Currentness_Reference: publication date
- Source_Citation_Abbreviation: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Source_Contribution: Hard copy of the Geologic map of North America.
- Process_Step:
-
- Process_Description:
-
Adobe Illustrator files containing the linework used for the hard copy production of the Geologic Map of North America (GMNA) were obtained from USGS cartographers in Reston, VA. The two (northern and southern) Illustrator source files were massive, with layer counts totaling over 1,500 each. Files were analyzed to determine if direct import from Adobe Illustrator to ArcGIS (via software like MaPublisher) would be the most efficient method of file conversion. When examined at scales far more detailed than that of the printed map, many areas were found to have problems in topological relationships. Common topological problems in these areas included polygons that overlapped or had gaps between them, overlying line layers (contacts, faults, etc.) which were not coincident with polygon boundaries, and line features that self-overlapped. Although these problems were irrelevant to preparation of the hard copy map, they were unsuitable for feature class generation.
To minimize topological errors (estimated in the hundreds of thousands), features were created via a combination of direct export from Illustrator and raster auto-vectorization. Layers containing linework coincident with geologic unit boundaries were batch exported from Illustrator with the exception of the geologic contacts layer. The geologic contact layer was exported as a series of high-resolution monochrome tiles. Raster tiles exported from Adobe Illustrator were georeferenced to local geographic coordinate positions using control points in the DNAG projection (Snyder, 1987). Images were auto-vectorized using ArcScan. Gaps and overlaps between tiles were rectified via raster painting tools. To create a topologically clean layer, topology rules were set in ArcMap and line dangles in the newly vectorized layer were snapped to the nearest unit-bordering line features.
Geologic unit layers were batch exported from the source Illustrator files and used as overlays for attributing the newly created polygon feature class. Through spatial querying, polygons in the unattributed layer that had their center within a specific overlay layer were attributed based on the overlay's geologic unit abbreviation. Remaining attribution for all other fields was completed quickly through VBA field calculator scripting based on the populated unit abbreviation field. Feature class symbolization was created to closely resemble the printed version of the GMNA. Finally, feature class symbology was exported to layer and style files.
- Source_Used_Citation_Abbreviation: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Process_Date: 2007
- Process_Contact:
-
- Contact_Information:
-
- Contact_Person_Primary:
-
- Contact_Person: Christopher Garrity
- Contact_Organization: U.S. Geological Survey
- Contact_Position: Cartographer
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: 12201 Sunrise Valley Drive
- Address: Mail Stop 956
- City: Reston
- State_or_Province: VA
- Postal_Code: 20192
- Country: USA
- Contact_Voice_Telephone: 703-648-6426
- Contact_TDD/TTY_Telephone: 703-648-6426
- Contact_Facsimile_Telephone: 703-648-6419
- Contact_Electronic_Mail_Address: cgarrity@usgs.gov
- Hours_of_Service: 9:00AM - 6:00PM
- Contact_Instructions: Preferred contact method is electronic mail.
- Spatial_Data_Organization_Information:
-
- Direct_Spatial_Reference_Method: Vector
- Point_and_Vector_Object_Information:
-
- SDTS_Terms_Description:
-
- SDTS_Point_and_Vector_Object_Type: G-polygon
- Point_and_Vector_Object_Count: 39828
- Spatial_Reference_Information:
-
- Horizontal_Coordinate_System_Definition:
-
- Planar:
-
- Map_Projection:
-
- Map_Projection_Name: Transverse Mercator
- Transverse_Mercator:
-
- Scale_Factor_at_Central_Meridian: 0.926000
- Longitude_of_Central_Meridian: -100.000000
- Latitude_of_Projection_Origin: 0.000000
- False_Easting: 0.000000
- False_Northing: 0.000000
- Planar_Coordinate_Information:
-
- Planar_Coordinate_Encoding_Method: coordinate pair
- Coordinate_Representation:
-
- Abscissa_Resolution: 0.000100
- Ordinate_Resolution: 0.000100
- Planar_Distance_Units: meters
- Geodetic_Model:
-
- Horizontal_Datum_Name: D_User_Defined
- Ellipsoid_Name: User_Defined_Spheroid
- Semi-major_Axis: 6371204.000000
- Denominator_of_Flattening_Ratio: infinity
- Vertical_Coordinate_System_Definition:
-
- Altitude_System_Definition:
-
- Altitude_Resolution: 0.000100
- Altitude_Encoding_Method:
-
Explicit elevation coordinate included with horizontal coordinates
- Entity_and_Attribute_Information:
-
- Detailed_Description:
-
- Entity_Type:
-
- Entity_Type_Label: Geologic_units
- Entity_Type_Definition:
-
Geologic unit polygons. Units are defined on the basis of age, origin, and where possible, composition.
- Entity_Type_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute:
-
- Attribute_Label: OBJECTID
- Attribute_Definition: Internal feature number.
- Attribute_Definition_Source: ESRI
- Attribute_Domain_Values:
-
- Unrepresentable_Domain:
-
Sequential unique whole numbers that are automatically generated.
- Attribute:
-
- Attribute_Label: Shape
- Attribute_Definition: Feature geometry.
- Attribute_Definition_Source: ESRI
- Attribute_Domain_Values:
-
- Unrepresentable_Domain: Coordinates defining the features.
- Attribute:
-
- Attribute_Label: UNIT_ABBREV
- Attribute_Definition:
-
Geologic unit abbreviation. Generally used for map labeling purposes.
- Attribute_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Unrepresentable_Domain:
-
Unit ages are indicated by uppercase letters and by lowercase letters and/or numbers preceding them. The lowercase letters and numbers indicate subdivisions of time-stratigraphic units. For a detailed description of how value definitions were constructed see the Entity_and_Attribute_Overview section of the metadata.
- Attribute:
-
- Attribute_Label: ROCKTYPE
- Attribute_Definition: Main classes into which rocks are divided.
- Attribute_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Sedimentary
- Enumerated_Domain_Value_Definition:
-
A rock resulting from the consolidation of loose sediment that has accumulated in layers; e.g. a clastic rock consisting of mechanically formed fragments of older rock transported from its source and deposited in water or from air or ice; or a chemical rock formed by precipitation from solution; or an organic rock consisting of the remains or secretions of plants and animals.
- Enumerated_Domain_Value_Definition_Source:
-
Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Plutonic
- Enumerated_Domain_Value_Definition:
-
A rock formed at considerable depth by crystallization of magma and/or by chemical alteration. It is characteristically medium-to coarse-grained, of granitoid texture.
- Enumerated_Domain_Value_Definition_Source:
-
Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Volcanic
- Enumerated_Domain_Value_Definition:
-
A generally finely crystalline or glassy igneous rock resulting from volcanic action at or near the Earth's surface, either ejected explosively or extruded as lava. The term includes near-surface intrusions that form a part of the volcanic structure.
- Enumerated_Domain_Value_Definition_Source:
-
Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Metamorphic and undivided crystalline
- Enumerated_Domain_Value_Definition:
-
A rock derived from pre-existing rocks by mineralological, chemical, and/ or structural changes, essentially in the solid state, in response to marked changes in temperature, pressure, shearing stress, and chemical environment, generally at depth in the Earth's crust. Unit can also include plutonic rock (defined elsewhere).
- Enumerated_Domain_Value_Definition_Source:
-
Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute:
-
- Attribute_Label: LITHOLOGY
- Attribute_Definition: Lithologic descriptions of non-sedimentary rocks.
- Attribute_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Alkaline complex
- Enumerated_Domain_Value_Definition: Rock mass made up largely or entirely of alkalic igneous rocks.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Alkaline diorite gabbro and syenite
- Enumerated_Domain_Value_Definition: Alkaline suite composed of diorites, gabbros, and syenites.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Alkaline mafic and intermediate rocks
- Enumerated_Domain_Value_Definition:
-
Mafic and intermediate rocks that have relatively high values of total alkali minerals.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Alkaline mafic rocks
- Enumerated_Domain_Value_Definition:
-
Mafic rocks that have relatively high values of total alkali minerals.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Alkaline rocks
- Enumerated_Domain_Value_Definition:
-
Any igneous rock in which the molecular ratio [(Na2O + K2O): Al2O3:SiO2] differs from 1:1:6 by deficiency in either Al2O or SiO2.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Anorthosite
- Enumerated_Domain_Value_Definition:
-
A plutonic rock with a plagioclase feldspar component greater than 90%, a quartz component between 0 and 5%, and a mafic component less than 10%.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Bimodal rocks (mafic and alkaline mafic)
- Enumerated_Domain_Value_Definition:
-
Rocks with subequal percentages of mafic and alkaline mafic components.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Charnockite
- Enumerated_Domain_Value_Definition:
-
An orthopyroxene-bearing granite. Most classifications require that quartz constitute at least 20% of the felsic constituents and that the ratio of alkali feldspar to total feldspar fall between 40% and 90%.
- Enumerated_Domain_Value_Definition_Source:
-
Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Diabase
- Enumerated_Domain_Value_Definition:
-
An intrusive rock whose main components are labradorite and pyroxene and which is characterized by ophitic texture.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Early tonalite plutons in the Superior province
- Enumerated_Domain_Value_Definition:
-
Plutons in the Superior province that are composed of tonalite, a light-colored coarse-textured, intrusive igneous rock containing more than 20% quartz.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Felsic and intermediate rocks
- Enumerated_Domain_Value_Definition:
-
Map unit contains felsic (defined elsewhere) and intermediate (defined elsewhere) rocks.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Felsic and mafic rocks
- Enumerated_Domain_Value_Definition:
-
Map unit contains felsic (defined elsewhere) and mafic (defined elsewhere) rocks.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Felsic rocks
- Enumerated_Domain_Value_Definition:
-
Igneous rock having abundant light-colored minerals in its mode. Felsic is a mnemonic adjective derived from feldspar + lenad (feldspathoid) +silica + c.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Felsite
- Enumerated_Domain_Value_Definition:
-
A general term for any light-colored, fine-grained or aphanitic extrusive or hypabyssal rock, with or without phenocrysts and composed chiefly of quartz and feldspar; a rock characterized by felsitic texture.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Gabbro-anorthosite
- Enumerated_Domain_Value_Definition:
-
Composed of gabbroic rock (a group of dark-colored, coarse-grained, basic intrusive igneous rocks composed mostly of calcic plagioclase and clinopyroxene) and anorthositic rock (coarse-grained igneous rock composed mostly of plagioclase and lesser amounts of pyroxene).
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Granite
- Enumerated_Domain_Value_Definition:
-
Light-colored plutonic rocks composed chiefly of quartz and feldspar and small amounts of mica, hornblende, and other minerals.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Impact breccia
- Enumerated_Domain_Value_Definition:
-
A coarse-grained rock composed of angular broken rock fragments, produced by an impact event such as a meteorite striking the earth.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Interlayered sedimentary and alkaline volcanic rocks
- Enumerated_Domain_Value_Definition:
-
Map unit contains interlayered sedimentary and alkaline (defined elsewhere) volcanic rocks.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Interlayered sedimentary and mafic volcanic rocks
- Enumerated_Domain_Value_Definition:
-
Map unit contains interlayered sedimentary and mafic (defined elsewhere) volcanic rocks.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Interlayered sedimentary and volcanic rocks
- Enumerated_Domain_Value_Definition: Map unit contains interlayered sedimentary and volcanic rocks.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Intermediate and mafic rocks
- Enumerated_Domain_Value_Definition:
-
Map unit contains intermediate (defined elsewhere) and mafic (defined elsewhere) rocks.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Intermediate rocks
- Enumerated_Domain_Value_Definition:
-
Medium- to dark-gray plutonic or volcanic rocks composed of roughly equal amounts of quartz, feldspar, mica, and hornblende.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Late felsic and intermediate plutons in the Superior province
- Enumerated_Domain_Value_Definition:
-
Plutons in the Superior province that are composed felsic and intermediate (defined elsewhere) intrusive igneous rocks.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Mafic and ultramafic rocks
- Enumerated_Domain_Value_Definition:
-
Map unit contains mafic (defined elsewhere) and ultramafic (defined elsewhere) rocks.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Mafic rocks
- Enumerated_Domain_Value_Definition:
-
Said of dark-colored plutonic or volcanic rocks composed chiefly of feldspar and dark minerals rich in iron and magnesium, such as hornblende, pyroxene, and olivine, and containing little or no quartz.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Mainly tonalite gneiss
- Enumerated_Domain_Value_Definition:
-
A coarse-textured, metamorphic rock that originated as a light-colored plutonic (intrusive) rock containing more than 20% quartz.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Marble
- Enumerated_Domain_Value_Definition:
-
A metamorphic rock consisting predominantly of fine-to coarse-grained recrystallized calcite and/or dolomite.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Orthogneiss
- Enumerated_Domain_Value_Definition: A gneiss formed from igneous rocks.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Paragneiss
- Enumerated_Domain_Value_Definition: A gneiss formed from sedimentary rocks.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Quartzite (Early Proterozoic)
- Enumerated_Domain_Value_Definition:
-
A granoblastic metamorphic rock consisting mainly of quartz and formed by recrystallization of sandstone or chert by either regional or thermal metamorphism.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Sedimentary and volcanic gneiss
- Enumerated_Domain_Value_Definition: A gneiss of sedimentary and/or volcanic origin.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Syenite gneiss
- Enumerated_Domain_Value_Definition:
-
A coarse-textured, metamorphic rock that originated as a plutonic (intrusive) rock containing alkali feldspar (usually orthoclase, microcline, or perthite), a small amount of plagioclase (less than in monzonite), one or more mafic minerals (esp. amphibole), and quartz, if present, only as an accessory.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Syenite, monzogranite
- Enumerated_Domain_Value_Definition:
-
An intrusive rock containing alkali feldspar (usually orthoclase, microcline, or perthite), plagioclase, one or more mafic minerals (esp. amphibole), and quartz, if present, only as an accessory.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Tonalite
- Enumerated_Domain_Value_Definition:
-
An intrusive rock with a quartz component between 20 and 60%, feldspar is present as plagioclase with 10% or less alkali feldspar.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Two-mica granite
- Enumerated_Domain_Value_Definition:
-
A granite containing both dark mica (biotite) and light mica (muscovite).
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Ultramafic rocks
- Enumerated_Domain_Value_Definition: An igneous rock composed chiefly of mafic minerals.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value:
-
Undivided crystalline rocks (seafloor units may include a variety of metamorphosed rock)
- Enumerated_Domain_Value_Definition:
-
Igneous rock, composition and grain size not specified. In seafloor units, includes metamorphic rocks.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Undivided gneissic rocks
- Enumerated_Domain_Value_Definition:
-
Coarse-textured metamorphic rock, shown together rather than separately at this map scale.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Undivided granitic rocks
- Enumerated_Domain_Value_Definition:
-
Various igneous rocks of granitic (defined elsewhere) composition, shown together rather than separately at this map scale.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Undivided volcanic rocks
- Enumerated_Domain_Value_Definition:
-
Various types of volcanic rocks, shown together rather than separately at this map scale.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Volcanic gneiss
- Enumerated_Domain_Value_Definition: Gneiss of volcanic origin.
- Enumerated_Domain_Value_Definition_Source:
-
Modified from Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2005, Glossary of geology (5th ed.): Alexandria, Va., American Geological Institute, 779 p.
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: <Null>
- Enumerated_Domain_Value_Definition: Null values indicate the unit is sedimentary.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute:
-
- Attribute_Label: MIN_AGE
- Attribute_Definition:
-
Minimum (youngest) geologic age of the rock unit. By convention, the term "Lower" refers to all rocks except intrusive igneous rocks which, owing to their method of emplacement, are referred to as being of age "Early".
- Attribute_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Age unknown
- Enumerated_Domain_Value_Definition: The age of the map unit is unknown.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Archean
- Enumerated_Domain_Value_Definition:
-
The first eon of the Precambrian. It extended from about 3.8 billion to 2.5 billion years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Cambrian
- Enumerated_Domain_Value_Definition:
-
The first period of the Paleozoic Era. It extended from about 543 to 490 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Cretaceous
- Enumerated_Domain_Value_Definition:
-
The last period of the Mesozoic Era. It extended from about 144 to 65 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Devonian
- Enumerated_Domain_Value_Definition:
-
A subdivision of the Paleozoic Era that extended from about 417 to 354 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Early Archean
- Enumerated_Domain_Value_Definition:
-
The first major subdivision of the Archean Eon. It extended from about 3.8 to 3.4 billion years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Early Cretaceous
- Enumerated_Domain_Value_Definition:
-
The first epoch of the Cretaceous Period. It extended from about 144 to 99 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Early Proterozoic
- Enumerated_Domain_Value_Definition:
-
The first major subdivision of the Proterozoic Eon. It extended from about 2.5 to 1.6 billion years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Eocene
- Enumerated_Domain_Value_Definition:
-
A subdivision of the Paleogene Period. It extended from about 54.8 to 33.7 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Jurassic
- Enumerated_Domain_Value_Definition:
-
A subdivision of the Mesozoic Era. It extended from about 206 to 144 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Late Archean
- Enumerated_Domain_Value_Definition:
-
The last major subdivision of the Archean Eon. It extended from about 3.0 billion to 2.5 billion years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Late Cretaceous
- Enumerated_Domain_Value_Definition:
-
The last epoch of the Cretaceous Period. It extended from about 99 to 65 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Late Jurassic
- Enumerated_Domain_Value_Definition:
-
The last epoch of the Jurassic Period. It extended from about 159 to 144 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Late Proterozoic
- Enumerated_Domain_Value_Definition:
-
The last major subdivision of the Proterozoic Eon. It extended from about 900 million to 543 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Lower Cretaceous
- Enumerated_Domain_Value_Definition:
-
The first epoch of the Cretaceous Period. It extended from about 144 to 99 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Lower Devonian
- Enumerated_Domain_Value_Definition:
-
The first epoch of the Devonian Period. It extended from about 417 to 391 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Lower Eocene
- Enumerated_Domain_Value_Definition:
-
The first major subdivision of the Eocene Epoch. It extended from about 54.8 to 49 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Lower Jurassic
- Enumerated_Domain_Value_Definition:
-
The first major subdivision of the Jurassic Period. It extended from about 206 to 180 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Lower Mississippian
- Enumerated_Domain_Value_Definition:
-
The first major subdivision of the Mississippian Period. It extended from about 354 to 342 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Lower Ordovician
- Enumerated_Domain_Value_Definition:
-
The first major subdivision of the Ordovician Period. It extended from about 490 to 470 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Lower Pennsylvanian
- Enumerated_Domain_Value_Definition:
-
The first major subdivision of the Pennsylvanian Period. It extended from about 323 to 311 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Lower Permian
- Enumerated_Domain_Value_Definition:
-
The first major subdivision of the Permian Period. It extended from about 290 to 256 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Lower Silurian
- Enumerated_Domain_Value_Definition:
-
The first major subdivision of the Silurian Period. It extended from about 443 to 423 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Mesozoic
- Enumerated_Domain_Value_Definition: The era that extended from about 248 to 65 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Middle Archean
- Enumerated_Domain_Value_Definition:
-
A subdivision of the Archean Eon. It extended from about 3.4 to 3 billion years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Mid-Cretaceous
- Enumerated_Domain_Value_Definition:
-
A subdivision (informal) of the Cretaceous Period. It extends from 88 to 108 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Middle Devonian
- Enumerated_Domain_Value_Definition:
-
A subdivision of the Devonian Period. It extended from about 391 to 370 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Middle Eocene
- Enumerated_Domain_Value_Definition:
-
A subdivision of the Eocene Epoch. It extended from about 49 to 41.3 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Middle Jurassic
- Enumerated_Domain_Value_Definition:
-
A subdivision of the Jurassic Period. It extended from about 180 to 159 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Middle Ordovician
- Enumerated_Domain_Value_Definition:
-
A subdivision of the Ordovician Period. It extended from about 470 to 458 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Middle Proterozoic
- Enumerated_Domain_Value_Definition:
-
A subdivision of the Proterozoic Eon. It extended from about 1600 to 900 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Miocene
- Enumerated_Domain_Value_Definition:
-
The first epoch of the Neogene Period. It extended from about 23.8 to 5.3 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Mississippian
- Enumerated_Domain_Value_Definition:
-
The period in the Paleozoic Era that extended from about 354 to 323 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Neogene
- Enumerated_Domain_Value_Definition:
-
The last major subdivision of the Tertiary Period. It extended from about 24 to 1.8 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Oligocene
- Enumerated_Domain_Value_Definition:
-
The last epoch of the Paleogene Period. It extended from about 33.7 to 23.8 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Ordovician
- Enumerated_Domain_Value_Definition:
-
A subdivision of the Paleozoic Era. It extended from about 490 to 443 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Paleocene
- Enumerated_Domain_Value_Definition:
-
The first epoch of the Paleogene Period. It extended from about 65 to 54.8 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Paleogene
- Enumerated_Domain_Value_Definition:
-
The first major subdivision of the Tertiary Period. It extended from about 65 to 24 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Paleozoic
- Enumerated_Domain_Value_Definition: The era that extended from about 543 to 248 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Pennsylvanian
- Enumerated_Domain_Value_Definition:
-
The period in the Paleozoic Era that extended from about 323 to 290 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Permian
- Enumerated_Domain_Value_Definition:
-
The last period in the Paleozoic Era. It extended from about 290 to 248 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Pleistocene
- Enumerated_Domain_Value_Definition:
-
The first epoch of the Quaternary Period. It extended from about 1.8 to 0.01 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Pliocene
- Enumerated_Domain_Value_Definition:
-
The last epoch of the Neogene Period. It extended from about 5.3 to 1.8 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Precambrian
- Enumerated_Domain_Value_Definition:
-
The interval of geologic time prior to the beginning of the Paleozoic Era. It extended from the origin of the Earth to about 540 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Pre-Cenozoic
- Enumerated_Domain_Value_Definition:
-
The interval of geologic time (informal) prior to the beginning of the Cenozoic Era. It extended from the origin of the Earth to about 65 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Pre-Cretaceous
- Enumerated_Domain_Value_Definition:
-
The interval of geologic time (informal) prior to the beginning of the Cretaceous Period. It extended from the origin of the Earth to about 144 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Quaternary
- Enumerated_Domain_Value_Definition:
-
The last period of the Cenozoic Era. It began about 1.8 million years ago and extends to the present.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Silurian
- Enumerated_Domain_Value_Definition:
-
A subdivision of the Paleozoic Era. It extended from about 443 to 417 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Tertiary
- Enumerated_Domain_Value_Definition:
-
The first period of the Cenozoic Era. It extended from about 65 to 1.8 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Triassic
- Enumerated_Domain_Value_Definition:
-
The first period in the Mesozoic Era. It extended from about 248 to 206 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Upper Cambrian
- Enumerated_Domain_Value_Definition:
-
The last epoch of the Cambrian Era. It extended from about 500 to 490 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Upper Cretaceous
- Enumerated_Domain_Value_Definition:
-
The last epoch of the Cretaceous Period. It extended from about 99 to 65 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Upper Devonian
- Enumerated_Domain_Value_Definition:
-
The last epoch of the Devonian Period. It extended from about 370 to 354 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Upper Eocene
- Enumerated_Domain_Value_Definition:
-
The last major subdivision of the Eocene Epoch. It extended from about 37 to 33.7 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Upper Jurassic
- Enumerated_Domain_Value_Definition:
-
The last epoch of the Jurassic Period. It extended from about 159 to 144 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Upper Mississippian
- Enumerated_Domain_Value_Definition:
-
The last major subdivision of the Mississippian Period. It extended from about 327 to 323 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Upper Ordovician
- Enumerated_Domain_Value_Definition:
-
The last epoch of the Ordovician Period. It extended from about 458 to 443 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Upper Pennsylvanian
- Enumerated_Domain_Value_Definition:
-
The last major subdivision of the Pennsylvanian Period. It extended from about 296 to 290 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Upper Permian
- Enumerated_Domain_Value_Definition:
-
The last epoch of the Permian Period. It extended from about 256 to 248 million years ago.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute:
-
- Attribute_Label: MAX_AGE
- Attribute_Definition: Maximum (oldest) geologic age of the rock unit.
- Attribute_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Unrepresentable_Domain: See MIN_AGE attribute definitions.
- Attribute:
-
- Attribute_Label: MIN_MAX_RELATE
- Attribute_Definition:
-
Relationship between the minimum and maximum ages of the rock unit.
- Attribute_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: And
- Enumerated_Domain_Value_Definition:
-
Map unit consists of one or more subunits whose rocks are of age MIN_AGE, and one or more subunits whose rocks are of age MAX_AGE.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Or
- Enumerated_Domain_Value_Definition:
-
Map unit consists of one or more subunits whose rocks are of age MIN_AGE, or one or more subunits whose rocks are of age MAX_AGE.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Thru
- Enumerated_Domain_Value_Definition:
-
Map unit consists of one or more subunits whose rocks age(s), separately and/or together, range from MIN_AGE to MAX_AGE.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: And/Or
- Enumerated_Domain_Value_Definition:
-
Map unit consists of one or more subunits whose rocks are of age MIN_AGE, and one or more subunits whose rocks are of age MAX_AGE, and one or more subunits whose rocks range from MIN_AGE to MAX_AGE.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: <Null>
- Enumerated_Domain_Value_Definition:
-
Indicates age does not span more than one stratigraphic unit of time.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute:
-
- Attribute_Label: UNIT_UNCERTAINTY
- Attribute_Definition:
-
Indicates if the geologic unit composition is uncertain or, in the case of marine rocks and sediments that were sampled by dredging, whether the material is in situ or may have been introduced to the area by ice-rafting.
- Attribute_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Y
- Enumerated_Domain_Value_Definition: Indicates unit composition is uncertain.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: <Null>
- Enumerated_Domain_Value_Definition: Indicates the composition of the unit is relatively certain.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute:
-
- Attribute_Label: AGE_UNCERTAINTY
- Attribute_Definition:
-
Indicates uncertainty about the assigned age of the geologic unit.
- Attribute_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: Y
- Enumerated_Domain_Value_Definition: Indicates assigned age is uncertain.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Enumerated_Domain:
-
- Enumerated_Domain_Value: <Null>
- Enumerated_Domain_Value_Definition: Indicates the assigned age of the unit is relatively certain.
- Enumerated_Domain_Value_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute:
-
- Attribute_Label: MAP_UNIT_NOTE
- Attribute_Definition: Notes associated with selected rock units.
- Attribute_Definition_Source: Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E. (2005)
- Attribute_Domain_Values:
-
- Unrepresentable_Domain: Character string.
- Attribute:
-
- Attribute_Label: Shape_Length
- Attribute_Definition: Length of feature in internal units.
- Attribute_Definition_Source: ESRI
- Attribute_Domain_Values:
-
- Range_Domain:
-
- Range_Domain_Minimum: 60
- Range_Domain_Maximum: 57,401,694
- Attribute_Units_of_Measure: Meters
- Attribute:
-
- Attribute_Label: Shape_Area
- Attribute_Definition: Area of feature in internal units squared.
- Attribute_Definition_Source: ESRI
- Attribute_Domain_Values:
-
- Range_Domain:
-
- Range_Domain_Minimum: 126
- Range_Domain_Maximum: 3,071,973,073,462
- Attribute_Units_of_Measure: Square meters
- Overview_Description:
-
- Entity_and_Attribute_Overview:
-
Map units shown on the Geologic Map of North America are defined on the basis of age, origin, and where possible, composition. Phanerozoic rocks regionally metamorphosed to amphibolite facies or higher (or blueschist facies or higher in active orogenic belts) are distinguished by a diagonal line overprint layer, as are rocks metamorphosed to granulite facies in the Canadian shield. Other special lithologies and depositional environments such as melange, predominately continental deposits, and off-shelf (not offshore) marine deposits exposed on land are also indicated by overprint layers.
The unit labels used on the map are intended to provide the maximum amount of information for each map unit. This greatly simplifies the map explanation and minimizes the need to repeatedly refer to it. However, the system requires long and complex letter symbols. In order to interpret the symbols, it is necessary to be aware of the following:
1. Ages are indicated by uppercase letters and by lowercase letters and/or numbers preceding them. The lowercase letters and numbers indicate subdivisions of time-stratigraphic units. Most of these follow standard conventions, but because geologic special characters were substituted for standard characters, some are not obvious. Major subdivisions of time-stratigraphic units are generally indicated by l-lower, m-middle, and u-upper. In plutonic rocks the same subdivisions indicate Early, Middle, and Late. Further subdivisions are indicated by numbers, starting with the oldest = 1. In the Precambrian, superscripts are used for subdivisions, for example Y¹, Y², Y³. Combined units or units of uncertain age are indicated by double age designations, with the oldest age first. Where only an age designation appears in the unit label, the unit is sedimentary. In a few areas in the Canadian Shield and in the upper Midwest, the symbols Xcs and Xqz are used to identify units of Early Proterozoic sandstone and conglomerate, and quartzite, respectively.
2. For volcanic rocks, the age designation is followed by a lowercase "v" (e.g., plTv-Pliocene volcanic rocks). Lowercase letters following the "v" indicate lithology: f-felsic; i-intermediate; m-mafic; sv-mixed sedimentary and volcanic; b--bimodal; k-alkalic (e.g., plTvmk-Pliocene alkaline mafic volcanics).
3. For plutonic rocks, lowercase letters following the age designation indicate lithology: q-quartz monzonite and granite; g-undivided granitoid; f-felsite; i-granodiorite and quartz diorite; m-diorite and gabbro; y-syenite and monzodiorite; my-alkaline gabbro and syenite; a-anorthosite; and u-ultramafic.
4. For high-grade metamorphic rocks, age of the protolith is given. Lowercase letters following the age designation indicate lithology of the protolith: n-gneiss; sn-sedimentary gneiss; gn-granitic gneiss; and sgn- paragneiss and orthogneiss. Undivided crystalline rocks are indicated by x.
5. Lower-case letters without age designations indicate lithology of units of unknown or unspecified age: u- ultramafic rocks; x-crystalline rocks; g-granitoid rocks.
6. Seafloor units are indicated by single asterisks (*) following the unit abbreviation. Special seafloor units are indicated by two asterisks (**) following the unit abbreviation. Description of special seafloor units can be found in the "MAP_UNIT_NOTE" attribution field of the feature class.
7. Units with a query (?) before the unit abbreviation indicate uncertainty about age. Units with a query (?) after the unit abbreviation indicate uncertainty about composition, or whether the rock is in situ. Unit uncertainty information can also be queried via the "UNIT_UNCERTAINTY" and "AGE_UNCERTAINTY" attribution field(s) of the feature class.
Age designations for map units are as follows:
- CZ - Cenozoic
- Q - Quaternary
- pQ - Pleistocene
- T - Tertiary
- plT - Pliocene
- nT - Neogene
- mT - Miocene
- pgT - Paleogene
- oT - Oligocene
- eT - Eocene
- paT - Paleocene
- MZ - Mesozoic
- K - Cretaceous
- J - Jurassic
- TR - Triassic
- PZ - Paleozoic
- P - Permian
- PA - Pennsylvanian
- M - Mississippian
- D - Devonian
- S - Silurian
- O - Ordovician
- CA - Cambrian
- pCA - Precambrian
- Z - Late Proterozoic (570-900 Ma)
- Y - Middle Proterozoic (900-1600 Ma)
- Y¹ - Middle Proterozoic (1400-1600 Ma)
- Y² - Middle Proterozoic (1200-1400 Ma)
- Y³ - Middle Proterozoic (900-1200 Ma)
- X - Early Proterozoic (1600-2500 Ma)
- X¹ - Early Proterozoic (2100-2500 Ma)
- X² - Early Proterozoic (1800-2100 Ma)
- X³ - Early Proterozoic (1600-1800 Ma)
- A - Archean
- W - Late Archean
- Entity_and_Attribute_Detail_Citation:
-
Reed, J.C. Jr., Wheeler, J.O., and Tucholke, B.E., 2005, Geologic Map of North America - Perspectives and explanation: Boulder, Colorado, Geological Society of America, Decade of North American Geology, 28 p.
- Distribution_Information:
-
- Distributor:
-
- Contact_Information:
-
- Contact_Organization_Primary:
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- Contact_Organization: USGS Information Services
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: Box 25286
- City: Denver
- State_or_Province: CO
- Postal_Code: 80225
- Country: USA
- Contact_Voice_Telephone: 1-888-ASK-USGS
- Contact_TDD/TTY_Telephone: 1-888-ASK-USGS
- Contact_Facsimile_Telephone: 303-202-4693
- Contact_Electronic_Mail_Address: <http://store.usgs.gov/>
- Resource_Description: U.S. Geological Survey Data Series, Report Number 424, 2009
- Distribution_Liability:
-
This digital publication was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data published in this Data Series have been used by the USGS, no warranty, expressed or implied, is made by the U.S. Geological Survey as to the accuracy of the data and related materials and/or the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of this data, software, or related materials. Graphical map depictions are intended to be used within the map scale limits applicable to the source data. Although software enables the user to view data at various scales, the user is cautioned to refer to the source documentation for the appropriate map scale limitations.
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- Network_Resource_Name: <https://pubs.usgs.gov/ds/424>
- Online_Computer_and_Operating_System: Windows XP
- Fees: None
- Ordering_Instructions: <https://pubs.usgs.gov/ds/424>
- Turnaround: N/A
- Custom_Order_Process:
-
For those who wish to order this publication on Compact Disc, call 1-888-ASK-USGS (1-888-275-8747), visit <http://ask.usgs.gov>, contact any USGS Earth Science Information Center (ESIC), or write:
USGS Information Services
Box 25286
Denver, CO 80225
- Technical_Prerequisites:
-
ArcGIS Desktop 9.X is required to open the map document (GMNA_South.mxd).
- Metadata_Reference_Information:
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- Metadata_Date: 20090424
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- Contact_Person: Christopher Garrity
- Contact_Organization: U.S. Geological Survey
- Contact_Position: Cartographer
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- Address_Type: mailing address
- Address: 12201 Sunrise Valley Drive
- Address: Mail Stop 956
- City: Reston
- State_or_Province: VA
- Postal_Code: 20192
- Country: USA
- Contact_Voice_Telephone: 703-648-6426
- Contact_TDD/TTY_Telephone: 703-648-6426
- Contact_Facsimile_Telephone: 703-648-6419
- Contact_Electronic_Mail_Address: cgarrity@usgs.gov
- Hours_of_Service: 9:00 AM - 6:00 PM
- Contact_Instructions: Electronic mail is preferred method of contact
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Generated by mp version 2.9.6 on Fri Apr 24 10:22:42 2009