The document discusses the importance of creating coherent geologic maps for mineral exploration through field mapping and the use of geographic information systems (GIS). Key points include: - Professional quality geologic maps produced by field mapping are important tools that contain information used to make exploration decisions. - GIS allows for integration of field data, geochemical data, geophysical surveys, and drill holes to perform spatial analysis and generate derivative maps useful for exploration. - Underlying unseen data that contributes to coherent digital geologic maps includes lithology, structures, mineralization, geochemistry, and geophysics.

1. The Importance of Coherent Geologic
Maps in Mineral Exploration
Dean M. Peterson & Gabriel J. Sweet
Big Rock Exploration 1:200 Scale

2. Mineral Development Trapezoid
The Geologic Map Foundation

3. Creating the Geologic Map
Getting “Boots on the Ground” to observe &
record the geology of rock exposures &
surficial materials systematically.

4. Boots on the Ground:
Professional Quality Geology Maps
• Maps are one of the main means that field geologists
use to reporttheir findings
• Also, their field notes, presentations, discussions, etc..
• The map must be as accurate as possible
• Is it stratigraphically & structurally compatible
• Does it make sense Property scale? District scale? Region scale?
• The map must be visually appealing
• A good-looking map conveys the message that the author (the
field geologist) knows what they are doing (see below)
• In the mineral industry, these maps will be used by
many people for multiple reasons
• Therefore, it must contain enough ancillary information for
other people (whom are not as familiar with the geology as the
field geologist) to make decisions (drill hole targeting, investing,
etc..) based largely on what is conveyed on the map.
Professional Quality Geology Maps Have
• Title, Author(s), Date, Map Number
• Scale, North Arrow,CoordinateSystem
• Location Map
• Cross Section(s)
• Map Symbols
• Description of Map Units
• Correlation Diagram
• Explanatory Notes
• Introduction
• Structure (stereonet plots)
• Mineralization
• Thoughts, ideas, recommendations
• References

5. The Geologic Map
The Importance of Drawing Cross Sections
Rubber Hits the Road when you force yourself to draw geologic cross sections of a project area

6. The Digital Geologic Map
A Geographic Information System is a computer-based tool designed to capture, store,
manage, analyze, manipulate and visualize spatial or geographic information, usually in
map form. The true power of GIS lies in the ability to perform spatial analysis.
It is a tool for managing data, including points, lines, polygons, and imagery
• about where features are (coordinate data)
• what they are like (attribute data)
The ability to perform geological Spatial Analysis is why Coherent Geologic Maps must
be created by mineral industry geologists. Such maps derive their power from:
• Seamlesscompilation of multi-scale input data (ie. geology maps, geochemical data, geophysical data)
into a standardizedformat
• Understandable androbustattribute tables
• Integration with other information from government agencies/geologic surveys

7. The Unseen Data (OBSERVATIONS)
Behind Digital Geologic Maps
1) Lithology-based map units (for example: quartz-sericite-pyrite schist)
2) Locations of exposed rock (outcrop lithology, structure, textures, mineralogy, etc..)
3) Lines on the geology map (contacts, faults, shear zones, etc., rocks on each side of the line!!)
4) Orientation of the rocks (bedding, foliation, folding, lineation, etc..)
5) Mineral assemblages (mineral occurrences, alteration mineralogy, etc..)
6) Textures of the rocks (brecciated, faulted, sheared, altered, veined, etc..)
7) Mineral resources (calculated resources, mines, quarries, test pits, prospects, etc..)
8) Drill hole data in 3D (continuous lithology, assays, density, etc..)
9) Geochemical data (rocks, cores, till, soils, seeps, lake & stream sediment, etc..)
10) Geophysical data (magnetics, density, susceptibility, conductivity, resistivity, etc..)
If assembled correctly these unseen data behind geology maps can be used to create any
number of new Derivative Maps in Exploration Programs.

8. Derivative Map Generation
Mineral Occurrences
Data Behind This Map Area
• Outcrops:7,433
• Drill Holes: 589
• Drill Footage: 1,132,600 Feet
• Geochemistry: >60,000 samples
• VTEM Geophysical Survey (100m)
Detailed Bedrock Geology Map
(1:5,000 scale mapping)
Annotated Mineral OccurrenceMap (data
descriptions of outcrop and core intervals)

9. Awkward Segue: A Quick look at my
PhD & Current Work in Wyoming
UMD Geology Party, 1984
A quick 522 page read or 2.67 gigabyte download …..

10. Quick PhD Highlight Review:
Compilation of Analog Mining Camp Data

11. Orogenic Gold Model:
Data Driven Inference Net
• Standardized digital
compilations
• Create coherent GIS
geology maps
• Break apart the map into
componentsof the lode
gold ore deposit model
• Generate new derivative
fuzzy weighted Factor maps
of components
• Digitally combine Factor
maps into the final model

12. Classification of Primary Shear
Zones (compressional-parallel-extensional segments)

13. South Pass Greenstone Belt, Wyoming:
Roundtop Fault
Greenstone Greywacke

14. Classification of Subsidiary Shear Zones
Carissa Mine (photo by Ben Keute)

15. Important Subsidiary Shear Zone Details
Remember
One still needs to map the geology and structures in the field
P Shears account for
93% of the gold

16. South Pass Greenstone Belt, WY
Focusing Exploration

17. The Geologic Map
It’s all about the GIS Attribute Tables

18. A Concluding Geologic Tenet
“The distribution of outcrop is neither random or
representative”
Geologists out field mapping must search for insights on rocks that
perhaps are not exposed.

19. THANK YOU!
QUESTIONS?