Maryland Department of Natural Resources

Maryland Geologic Mapping Advisory Committee (GeoMAC)

The Geologic Mapping Advisory Committee (GeoMAC) advises the Survey and its Director on priorities for geologic mapping in Maryland. The primary objective of the mapping effort is to provide a basic framework of geologic information for water-resource evaluation, natural resource management, geologic hazard identification, land-use planning, economic development, scientific investigation and education. Much of the geologic mapping is conducted as part of a Federal and State Cooperative mapping program. Federal dollars utilized for geologic mapping under this program are awarded through an annual competitive grant process, and are matched by equivalent state dollars. The advice of the Committee is central to this program.

Meeting Frequency: Once per year.

<abbr title="Geologic Mapping Advisory Committee">GeoMAC</abbr> Members
Voting Members
Dr. Joel Moore (Chairperson)
Associate Professor of Geosciences
Expertise: Hydrogeology & Geochemistry
Department of Physics, Astronomy, & Geosciences
Towson University Science Complex
7801 York Road #236
Towson, MD 2104
(410)-704-2121
moore@towson.edu
Ms. Janet DeTore
Hillis-Carnes Engineering Associates, Inc.
Expertise: Civil & Geotechnical Engineering
Hillis-Carnes Corporate Headquarters
10975 Guilford Road, Suite A
Annapolis Junction, MD 20701
(410)-880-4788, ext 124
jdetore@hcea.com
Mr. Nathan Moore
Engineering Geology Division Chief
State of Maryland Office of Materials Technology
Expertise: Geotechnical roadway design
Maryland State Highway Administration
7450 Traffic Drive
Hanover, MD 21076
Office: (443)-572-5171
Toll Free: (866)-926-8501
NMoore@mdot.maryland.gov
Mr. Phillip "Phil" King
State Soil Scientist
District of Columbia, Maryland & Delaware
Expertise: Soil science & Geomorphology
USDA Natural Resource Conservation Service
Delaware Office
1221 College Park Drive, Suite 100
Dover, DE 19904
(302)-678-4172
phillip.king@de.usda.gov
Chief Edmond "Ed" Larrimore
Past Mining Program Administrator
Maryland Department of the Environment
Expertise: Oil, Gas, & Mineral exploration
Montgomery Park Business Center
1800 Washington Boulevard
Baltimore, MD 21230
(410)-537-3557
ed.larrimore@maryland.gov
Mr. Ethan Weikel
Deputy Director
Water Science Center
District of Columbia, Maryland & Delaware
Expertise: Hydrogeology & Structural geology
United States Geological Survey
5522 Research Park Drive
Baltimore, MD 21228
Office: (443)-498-5501
Cell: (410)-746-1897
eweikel@usgs.gov
Dr. James B. "Sam" Stribling
Director of Aquatic Ecology
Tetra Tech, Inc.
Expertise: Ecological assessment
10045 Red Run Boulevard, Suite 110
Owings Mills, MD 21117
(410)-356-8993
james.stribling@tetratech.com
Ms. Marion Wiggins
P.G. Senior Geologist
Vulcan Materials Company
Expertise: Construction aggregate mining
875 Oxford Avenue
Hanover, PA 17331
(717)-637-7121 ext 498
wigginsm@vmcmail.com
Dr. David A. Vanko
Emeritus Faculty
Past Dean of the College of Science & Mathematics
Expertise: Igneous and metamorphic petrology & Environmental geology
(410)-704-2121
dvanko@towson.edu
Non-Voting Members
Richard A. Ortt, Jr.
Head of Resource Assessment Service
Maryland Department of Natural Resources
Former Director & State Geologist
Maryland Geological Survey
Maryland Geological Survey
2300 Saint Paul Street
Baltimore, MD 21218
(410)-554-5503
richard.ortt@maryland.gov
Ms. Heather Quinn
Geologist
Hydrogeology & Hydrology Program
Maryland Geological Survey
2300 Saint Paul Street
Baltimore, MD&21218
(410)-554-5561
heather.quinn@maryland.gov
Mr. Stephen Van Ryswick
Director
Maryland Geological Survey
Maryland Geological Survey
2300 Saint Paul Street
Baltimore, MD&21218
(410)-554-5544
stephen.vanryswick@maryland.gov
Mr. Jeff Halka
Emeritus Director
Maryland Geological Survey
Ex officio

Maryland Geological Survey is a part of the Resource Assessment Service
Maryland Department of Natural Resources, State of Maryland
Updated April 14, 2026