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This is an Arc/Info coverage showing the general elevation of the top of the Herrin (No. 6) coal in Illinois. These 100-foot isolines were contoured by Earthvision software using more than 22,000 data points. The data was not contoured using fault lines for control and no manual adjustments were made to the contours to reflect the presence of known faults. Limited data were available in the north central and central portions of the state. This data set is intended for use at a scale of 1:750,000.
Outlines of areas mined for the Springfield coal in Illinois as of January 1, 1996. This information was extracted from detailed coal mine data stored in the ISGS Coal Section library database. Lines delineate the approximate outer boundary of individual mines (if known) or general mined areas. Interior mine boundaries such as pillars or small blocks of unmined coal are commonly not depicted. Outlines have been compiled from a variety of sources. Outlines of areas mined before 1987 are commonly from source maps at scales of 1:62,500 or smaller. Outlines of areas mined since 1987 are commonly digitized at scales ranging from 1:4800 to 1:12,000. Mines whose extent is not known or which only mined a few acres are not...
Thickness contours of 28", 42", and 66" were mapped for the Danville (No. 7) Coal in Illinois. This Arc/INFO coverage was created from public data only.
Sulfur content (pounds of sulfur per million Btu) was mapped for the Herrin (No.6) Coal in Illinois using point source data (primarily channel samples and drill cores), information from coal company geologists, and observation of geologic trends associated with the formation of sulfur in coal.
This image represents the relief in and around the Illinois Basin. It can be show in relation to other spatial data in the Illinois Basin.
The Quaternary Geologic Map of the Chicago 4� x 6� Quadranglewas mapped as part of the Quaternary Geologic Atlas of the United States.The atlas was begun as an effort to depict the areal distribution ofsurficial geologic deposits and other materials that accumulated orformed during the past 2+ million years, the period that includes allactivities of the human species. These materials are at the surface ofthe earth. They make up the "ground" on which we walk, the "dirt" inwhich we dig foundations, and the "soil" in which we grow crops. Mostof our human activity is related in one way or another to these surfacematerials that are referred to collectively by many geologists asregolith, the mantle of fragmental and generally...