Skip to main content

Stonehenge Formation

Stonehenge Formation - Medium-light-gray to medium-gray, finely crystalline, thick-bedded limestone, containing dark siliceous laminae, edgewise conglomerate beds, and fossil-fragment lenses; dolomite beds increase in number eastward.
State Pennsylvania
Name Stonehenge Formation
Geologic age Ordovician
Primary rock type limestone
Secondary rock type dolostone (dolomite)
Other rock types conglomerate
Lithologic constituents
Major
Sedimentary > Carbonate > Limestone (Bed)medium-light-gray to medium-gray, finely crystalline, thickbedded limestone, containing dark siliceous laminae, and fossil-fragment lenses
Minor
Sedimentary > Carbonate > Dolostone (Bed)medium-light-gray to medium-gray, finely crystalline, thickbedded limestone, containing dark siliceous laminae; dolomite beds increase in number eastward.
Incidental
Sedimentary > Clastic > Conglomerate (Bed)edgewise conglomerate beds
Map references
Pennsylvania Bureau of Topographic and Geologic Survey, Department of Conservation and Natural Resources, 2001, Bedrock Geology of Pennsylvania, edition: 1.0, digital map. Retrieved from internet 9-30-2004; <http://www.dcnr.state.pa.us/topogeo/map1/bedmap.aspx> DL Data: pageoexp.zip
Unit references
Berg, T. M., Edmunds, W. E., Geyer, A. R., and others, compilers, 1980, Geologic map of Pennsylvania: Pennsylvania Geological Survey, 4th ser., Map 1, 2nd ed., 3 sheets, scale 1:250,000.
Pennsylvania Bureau of Topographic and Geologic Survey, Department of Conservation and Natural Resources, 2001, Bedrock Geology of Pennsylvania, edition: 1.0, digital map. Retrieved from internet 9-30-2004; <http://www.dcnr.state.pa.us/topogeo/map1/bedmap.aspx> DL Data: pageoexp.zip