Great Basin GIS Detailed Geological Maps

Detailed Specifications

GIS format maps are created from geologic maps published by NBMG, USGS, and other sources, and are Microsoft Windows compatible. Maps are licensed: license gives right to use on multiple computers at a single office site (discount for additional site copies) and permission to distribute images and plots. Most maps are available in two standards of completion: As Published and Enhanced The As-Published map is a conversion of the published map to GIS format, and the Enhanced version starts from the As-Published version and compiles into it as much additional detailed data as I can find. Maps of both versions include GIS format vector map data separated into the following tables, where data is available (# indicates number of data fields).

As Published maps are designed to match the original published maps as much as possible. Colors, labels, symbology, and patterns are matched as closely as possible. All geological data located on the map itself is included, if possible. As Published maps are generally lower priced than Enhanced maps. As Published format maps include:

 Attitudes (bedding, foliation, etc) as points (8 inc. type, subtype, strike, dip, dip direction, label)

 Small structures (folds, slickensides, etc) as points (12, inc. type, subtype, axis trend, axis plunge, axial plane strike, axial plane dip, vergence, label)

 Faults as lines with point annotations (13, inc. type, name, strike, dip, dip direction, down to direction, L-R lateral, length, accuracy, certainty,

 Contacts as lines with point annotations (8, inc. type, strike, length, accuracy, certainty)

 Folds as lines with point annotations (14, inc. type, subtype, trend, plunge, strike, dip, vergence,

 Rock units as polygons and lines (15, inc. name, lithology, environment, period, subperiod, age(Ma), tectonic unit, label, original label, covered label, certainty)

 Complete explanation of each rock unit from the original descriptive text (3, label, line number, description)

 Alteration as polygons, lines and/or points (7, inc. type, subtype, strength, label)

 Radiometric age dates as points (13, inc. type, age, ±, lithology, material dated, reference)

 Fossils as points (8, inc. type, name, age, sample number, reference)

 Map area outline as lines (4, inc. type)

 Mineral data as polygons, lines and/or points (10, inc. type, subtype, name, accuracy, product, value)

 Mining data as polygons, lines and/or points (6, inc. type, subtype, name, product)

 Geochemistry (trace elements) as points(8+, depending on original data)

 Mapping sources as polygons and lines (3, Geologist, scale, source)

 Errors and inconsistencies in the original map as points(type, result, and source)

 Cross-sections as georeferenced raster images

 Correlation chart as raster image

Enhanced format maps: These are compiled from multiple sources, starting with the As-Published version, if available. Thus, I typically add detailed maps from theses, guidebooks and other publications, better isotopic age-date and fossil data, open pit outlines, and grade or GT contours. In some cases I do limited bedrock photogeological mapping and field checks. Enhanced version maps have standardized formats for the various tables and are optimized to facilitate analysis, especially where adjacent maps have been combined into one. Their formats are completely consistent with each other. I strive for no loss of detail compared to the original source material. Enhanced maps contain all the content of the As-Published map, and also have the following additions:

 Map edges are spatially matched to adjacent maps

 Rock map units shown as lines are converted to polygons, and put in the same table as the rock polygons

 Alteration map units, lines and points are converted to transparent pattern polygons

 Alluvial units are re-interpreted using aerial photographic techniques

 Labels, colors, alteration patterns and annotation schemes for all tables are standardized

 Cross-sections are edited to match the Enhanced format map color and label schemes.

 Generalized lithologies are added (i.e. "sandstone" added where "litharenite" is the only lithology described)

 Additional fault characteristics are interpreted from the map pattern (primarily down-to directions)

 Intrusive and major unconformity contacts are identified and named

  A special custom correlation chart reflecting the Enhanced format color and label schemes

 Table containing the general descriptions of the enhanced labels

 Corrections, updates and/or additions to all tables are made from accompanying text, other publications or data. In mineralized areas, a great deal of additional detailed mineral information may be included

 Multiple quads purchased at the same time can be merged into single map files at no extra cost

 Data structure for all tables is standardized

 Topographic contour lines in feet and meters are included (contoured from USGS DEM)  

The following is also provided with any map license:

 Proprietary geology Windows symbol font (~150 geology map symbols) and geology Windows text font (standard text, plus 22 geology age characters)

 Display software for cross-sections, description text, correlation charts, and geologic text font (Mapinfo only)