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Rockdale Run Formation

Rockdale Run Formation - Upper one-third gray, mottled, cherty dolomite and dolomitic limestone; lower two-thirds gray, cherty argillaceous calcarenite and algal limestone with interbedded dolomite and oolitic limestone; thickness at least 1,700 feet east of Conococheague Creek, increases to about 2,500 feet in west.
State Maryland
Name Rockdale Run Formation
Geologic age Ordovician
Primary rock type dolostone (dolomite)
Secondary rock type limestone
Other rock types calcarenite
Lithologic constituents
Sedimentary > Carbonate > Dolostone
Sedimentary > Carbonate > Limestone
Sedimentary > Clastic > Sandstone > Arenite > Calcarenite
Map references
Cleaves, E.T., Edwards, J., Jr., Glaser, J.D., 1968, Geologic Map of Maryland: Maryland Geological Survey, Baltimore, Maryland, scale 1:250,000.
Unit references
Unpublished digital version of the Maryland state geologic map that was digitized by the USGS Water Resources Office in Towson, MD
Counties Washington