Three-Dimensional Geologic Mapping for Environmental Studies in Illinois

摘要

Stack-unit maps show the geologic framework of an area in three dimensions, depicting not only the areal distribution of geologic deposits and formations, but also their vertical distribution from the ground surface to a designated depth. The map may be presented as an outline map with each stack unit labeled within the limit of its boundary, by some simple arrangement of color and/or pattern indicating both surface and subsurface units, or by some combination of labels, colors, and patterns. The technique for preparing three-dimensional stack-unit maps has evolved for the last 20 years and is currently a method for depicting the surficial and near-surface deposits of Illinois at the Illinois State Geological Survey. Interpretive maps for most geologic, land use, and resource evaluation can be made directly from this basic stack-unit map, given the physical and mineralogical properties for each unit and a set of criteria for each interpretative map.