DIGITALLY REVISED PRECAMBRIAN BASEMENT MAP OF WYOMING

The structural configuration of basement rock, both at the surface and in the subsurface, is fundamental to understanding the complete geology of a region. In Wyoming, the igneous and metamorphic Precambrian rocks that comprise the “basement” are exposed at the surface in basement-cored mountain ranges that reach elevations greater than 13,000 feet above sea level. Despite being covered by thick (locally up to 40,000 feet) sequences of Phanerozoic strata in the adjacent basins, the basement structural configuration influences many aspects of basin geology ranging from sediment accumulation, to faulting and folding, to formation and alteration of hydrocarbon and mineral deposits. For these reasons, the Precambrian basement map of Wyoming, by D.L. Blackstone, Jr., has been a primary and authoritative reference for Wyoming geology since initial publication in 1993.

With partial funding from the National Geological and Geophysical Data Preservation Program, which is aimed at identifying critical-mineral resources throughout the United States, the Wyoming State Geological Survey revised and updated the Precambrian basement map of Wyoming with the intention of providing a similarly useful product that considers new information and modernizes the map in a digital format. All available public information, especially including wells, seismic lines, cross sections, geologic maps, and digital elevation models, were used to refine and, in places, reinterpret the statewide Precambrian basement elevation, relative to mean sea level, at the scale of 1:500,000. The resulting dataset and associated metadata are organized and publicly available in a U.S. Geological Survey standardized geodatabase schema and in a Wyoming State Geological Survey online map.