GEOLOGIC MAPPING COALITIONS: ADDRESSING THE NEED FOR A U.S. NATIONAL COMMITMENT FOR THREE-DIMENSIONAL GEOLOGIC MODELS AND DERIVATIVE MAPS

Policy makers constantly must evaluate often competing options for managing land and water resources. They must balance choices impacting economic growth with the increasing needs of growing and shifting populations, geohazards that could put people and property at risk, and with the goal of sustainably managing limited land, water, and mineral resources. Unlike most areas of the U.S., planners in the Great Lakes states must consider thick (up to 300m), complex, and generally poorly mapped glacial and related sediments, that are the context for resource, environmental, and hazard issues and which require specialized/costly geologic investigations to map.

To address stakeholder-defined need for detailed 3D modeling and mapping, geological surveys of the eight Great Lakes states and the USGS formed the Great Lakes Geologic Mapping Coalition in 1997. The Coalition’s mission is to develop dynamic databases, from which updatable 3D geologic models of unconsolidated deposits, and derivative maps that directly support critical earth resource decisions can be produced. With full realization that no single state or the USGS has the mandate, tools, or financial/personnel resources to perform this alone, Coalition partners banded together with a unified vision for regional mapping (1) using a standard approach to making geologic models, (2) proposing short-term (3 years) and long-term (14 years) mapping priorities with stakeholder input, (3) detailing and sharing in-house capabilites and needs for field investigations, laboratory analysis, modeling and mapping support, (4) establishing time lines and personnel requirements for mapping, and (5) specifying derivative maps and potential user applications to be part of a science-based decision support system. In the 12 years since establishment, Coalition geologists jointly have shared their expertise and findings, while the participating geological surveys have shared staff, equipment, strategies, software, websites, and funding. The surveys have also collaborated closely in seeking additional federal funding to accomplish these mandates. The GLGM Coalition is an approach that was established regionally to advance the development of effective, relevant 3D geologic products, but which is applicable nationally.