Pages authored by Denver Harper:

1. Groundwater / Nitrate Contamination
   In Indiana, extensive agricultural areas were developed on glacial outwash deposited in floodways of major streams and on outwash fans and wind-blown sands.
2. Watershed Hydrology / Contaminated Steamflow
   In cooperation with the Biological Research Division of the U.S. Geological Survey (USGS), the Department of Geological Sciences of Indiana University (IU) and the Indiana Geological and Water Survey (IGWS) initiated a project to develop a basis for forecasting outfalls of E. coli into Lake Michigan from the Little Calumet...
3. Mine Reclamation / Abandoned Coal Mine Features
   Indiana is currently the sixth largest coal-producing state in the United States, and it has a long history of coal mining. Large-scale mining has been conducted by both underground and surface methods.
4. Mine Reclamation / Acid Mine Drainage
   Pyrite, or iron sulfide (FeS2), is a mineral that is commonly found within Indiana coal seams and the adjacent rock strata. When coal beds and surrounding rock units are disturbed during mining, the associated pyrite is exposed to oxygen and water, and chemical reactions produce highly mineralized acidic mine drainage (AMD).
5. Mine Reclamation / Midwestern Project Extension
   In February 1999, the Indiana Geological Survey reported on a project titled “Hydrology and Water Quality Associated with the Midwestern Reclamation Site (Site No. 1087), Pike County, Indiana.”
6. Mine Reclamation / Mine Spoil in Warrick County
   In cooperation with the Indiana State Department of Health (ISDH) and the Warrick County Department of Economic Development (WCDED), the Indiana Geological and Water Survey (IGWS) and the Department of Geological Sciences of Indiana University (IU) undertook a project to categorize deposits of mine spoil (the cast overburden from surface mining)...
7. Mine Reclamation / Reclamation in Indiana
   Acid mine drainage (AMD) is the cause of many environmental problems associated with abandoned mine lands. Where AMD is present, the abundance and variety of plant and animal life is greatly reduced, so that the land is susceptible to erosion and streams are subjected to siltation.
8. Other Hazards / Mine Subsidence in Indiana
   More than 900 million tons of coal has been removed from underground mines in southwestern Indiana, and more than 194,000 acres are underlain by such mines, most of which are abandoned. In places, as many as three different coal beds were mined (referred to as “multiseam mining”).
9. Carbondale Group / Linton Formation
   Type locality, reference section, and use of name: The Linton Formation was named by Wier (1950) for exposures along the tributaries of Lattas Creek in secs. 26 and 27, T. B N., R. 7 W., 4 miles north of Linton, Greene County, Ind.
10. Linton Formation / Survant Coal Member
    Type and reference sections and use of name: The name Survant Coal was applied by Fuller and Ashley (1902, p. 2) to exposures near the abandoned town of Survant in Pike County, Ind.
11. Coal / Coal-Slurry Deposits
    Indiana has a long history of coal mining by both underground and surface methods, and the state is still a major producer of coal (34.5 million tons in 2005, Indiana Coal Council).