Daniels, David L.

About the author


Illinois, Indiana, and Ohio magnetic and gravity maps and data

Aeromagnetic surveys of Illinois, Indiana, and Ohio, merged to form seamless grids across the state. Gravity anomaly data are provided as well.

Digital geologic map and database of the Frederick 30 X 60 minute quadrangle, Maryland, Virginia, and West Virginia

The geology of the Frederick 30 by 60 minute quadrangle, Maryland, Virginia, and West Virginia, was mapped on 1:24,000-scale base maps from 1989 to 1994. The geologic data were manually compiled at 1:100,000-scale in 1997 and were digitized and converted