Alaska Geologic Formations is a polygon theme representing geologic formations throughout Alaska. This dataset consists of a polygon coverage and associated attribute data derived from the 1980 Geologic Map of Alaska compiled by H.M. Beikman and published by the US Geological Survey. The map is a regional summary of geologic formations and units that can be shown cartographically at 1:2,500,000. This digital dataset includes all (184) map units from the original map. 182 are geologic units; the others are polygons for large glaciers and lakes. This coverage is not intended to be a complete representation of the printed geologic map. It does NOT include the following features: faults, locations of volcanoes or volcanic vents, the map explanation, correlation charts or description of map units.
Purpose
This coverage is intended to provide digital features (polygons) representing generalized geologic units in Alaska for use in small-scale spatial analysis (statewide) with other coverages such as vegetation types, soils, geochemical values etc.
Supplemental Information
The linework was digitized from a paper copy of the 1980 map at the EROS Data Center in Sioux Falls, South Dakota, and the resulting coverage (ARC/INFO version 5) transferred to the EROS Alaska Field Office. Although the latitude/ longitude grid shown on the published Beikman map was an Albers equal area projection, the geologic polygons were not in the same projection since they did not align with an Albers equal area coverage of the Alaskan coastline. A rubber-sheeting operation was performed on the geologic polygons using points along the coastline and major rivers to match an Albers equal area projection. In 1997, this coverage was imported into ARC/INFO version 7.0.4, and edited by the Alaska Section, Geologic Divsion, USGS. Map unit (polygon)locations and attributes were checked by three reviewers, by comparing a printed copy of the coverage to the original map. Metadata were collected using document.aml v. 7.1.1, distributed by ESRI, Inc.
Temporal Extent
Currentness Reference
ground condition
Time Instant
1980
Bounding Box
West
-179.142214
East
-129.993750
North
71.392025
South
51.217292
Theme Keyword
geoscientificinformation
Theme Keyword Thesaurus
ISO 19115 Topic Categories.
Theme Keyword
Geology
Theme Keyword Thesaurus
None
Place Keyword
Alaska
Place Keyword Thesaurus
Library of Congress Subject Headings
Temporal Keyword
1997
1980
Temporal Keyword Thesaurus
None
Access Restrictions
For current Columbia affiliates only.
Use Restrictions
For educational, non-commercial use only.
Status
Complete
Maintenance and Update Frequency
Unknown
Point of Contact
Contact Organization
LAND INFO Worldwide Mapping, LLC
Delivery Point
PO Box 261961
City
Highlands Ranch
State
CO
Postal Code
80163-1951
Country
USA
Contact Telephone
303-790-9730
Contact Electronic Mail Address
sales@landinfo.com
Native Data Set Environment
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.2.6.1500
Data Quality Information
Logical Consistency Report
Polygon and chain-node topology present.
Completeness Report
The following map features are not included in the digital representation: faults; locations of volcanoes and vents; explanation; and description of map units.
Lineage
Source
Originator
U.S. Geological Survey
Publication Date
1980
Title
Geologic Map of Alaska
Series Information
Series Name
Special publication
Issue Identification
SG0002-1T and SG0002-2T
Publication Information
Publication Place
Washington, D.C.
Publisher
U.S. Government Printing Office
Source Scale Denominator
2,500,000
Type of Source Media
paper
Source Temporal Extent
Time Period Information
Single Date/Time
Calendar Date
1980
Source Currentness Reference
publication date
Contribution
Direct copy
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
4303
Spatial Reference Information
Horizontal Coordinate System Definition
Geographic
Latitude Resolution
0.000000
Longitude Resolution
0.000000
Geographic Coordinate Units
Decimal degrees
Geodetic Model
Horizontal Datum Name
North American Datum of 1927
Ellipsoid Name
Clarke 1866
Semi-major Axis
6378206.400000
Denominator of Flattening Ratio
294.978698
Entity and Attribute Information
Entity Type
Entity Type Label
alaska_geo
Entity Type Definition
Geologic formations
Attributes
FID
Internal feature number. (Sequential unique whole numbers that are automatically generated.)
Definition Source
ESRI
Shape
Feature geometry. (Coordinates defining the features.)
Definition Source
ESRI
AREA
Area of polygon/region in square coverage units (square meters)
PERIMETER
Perimeter of polygon/region in coverage units (meters)
BEIKMANGEN
Internal feature number
GENERALIZE
DESC
Description
PERIOD
Period
Distribution Information
Distributor
LAND INFO Worldwide Mapping, LLC
Name
Metadata Reference Information
Metadata Date
20081001
Metadata Contact
Contact Information
Contact Organization Primary
Contact Organization
Research Data Services (RDS), Columbia University Libraries
Contact Person
GIS/Metadata Librarian
Contact Address
Address
420 W. 118th St., 215 IAB, MC 3301
City
New York
State or Province
NY
Postal Code
10027
Contact Voice Telephone
(212)854-6012
Contact Electronic Mail Address
data@library.columbia.edu
Metadata Standard Name
FGDC Content Standards for Digital Geospatial Metadata
