Maine’s Geology and...A Brief Word on Plate Tectonics Geology of Maine and New Brunswick Hibbard...
Transcript of Maine’s Geology and...A Brief Word on Plate Tectonics Geology of Maine and New Brunswick Hibbard...
Robert G. Marvinney State Geologist
Maine Geological Survey Dept Agriculture, Conservation and Forestry
Maine’s Geology and
Mineral Potential
November 9, 2012 Geological Society of Maine
Presentation Overview
Maine Geological Survey – who we are
Our place in the Northern Appalachians
Overview of Maine Geology
Important Mineral Discoveries
Types and Associations
Assistance from the Maine Geological Survey
Within the Department of Agriculture, Conservation and
Forestry, one of several Natural Resources departments in
Maine government
Programs in
Bedrock mapping
Surficial mapping
Groundwater resources characterization
Coastal/marine geology.
Hazards
Maine Geological Survey
Bedrock
and
Surficial
mapping
projects
Northern Appalachians
Northern Appalachian Terranes
Hibbard and others, 2006, Lithotectonic map of the Appalachian orogen
A Brief Word on Plate Tectonics
Geology of Maine and New Brunswick
Hibbard and others, 2006, Lithotectonic map of the Appalachian orogen
Significant
Mineral Deposits
Bald Mountain: 30 MT
Cu, Zn, Au, Ag
Alder Pond: 3 MT Zn,
Cu, Pb, Ag
Warren Nickel
Harborside and Second
Lake: Mined in the
1970s
Tectonic Settings of Metal Deposits
From Skinner and Porter, 1987
Tectonic Settings of Metal Deposits
Hydrothermal Vents
Porphyry Cu/Mo
Late stage of
granite intrusion
with extensive
fracture system
above cooling
magma.
Significant
Mineral Deposits
Commodity:
Base Metals
Cu, Pb, Zn, Fe, Ni,
(Mn)
Significant
Mineral Deposits
Commodity:
Precious Metals
(Au, Ag)
Significant
Mineral Deposits
Maine’s geology hosts
a variety of genetic
mineral deposit
types.
Maine Minerals Information on the Web
Significant Mineral Deposits
Google: Maine
Geological Survey
Significant Mineral Deposits
Google: Maine
Geological Survey Scanned Core Records
in Google Earth
Resources:
Geologists knowledgeable about Maine’s mineral
resources.
Geologic maps and reports.
Core facility – hundreds of core and logs from past
exploration.
Assistance:
Guidance on land ownership.
Listing of consulting geologists in Maine.
Contact information for regulatory agencies.
Maine Geological Survey
Current Activities:
Geologic mapping – bedrock and surficial.
Groundwater investigations.
Geologic hazards.
Future Activities:
Web-accessible core logs.
Statewide airborne geophysical survey.
Maine Geological Survey
Exploration
History
Basic geologic
mapping 1837-1950
identified coastal
base metal deposits.
1950s-1960s:
Government-funded
airborne geophysical
surveys identified
prospective areas.
1970s-1980s: Privately
funded exploration
in northern volcanic
belts.
Geology
Many diverse geologic environments.
Igneous and Volcanic terranes that may host a
variety of deposits.
Metal deposits
Numerous mineral occurrences.
Several well-characterized deposits.
Opportunities for undiscovered resources.
Summary
Prospecting in Maine