Clinton Group, including Rochester Shale (MDSc;1)

Clinton Group, including Rochester Shale - Gray, thin-bedded calcareous shale and dark gray, thin- to medium-bed7 ded lenticular limestone; thickness 25 to 40 feet; Keefer Sandstone - White to yellowish-gray, thick-bedded protoquartzite and orthoquartzite; calcareous to west; thickness 10 feet in west, increases to 35 feet in east; and Rose Hill Formation - Olive-gray to drab, thin-bedded shale; some purple shale and gray, thin-bedded sandstone; including Cresaptown Iron Sandstone Member - Purple, hematite-cemented, quartzose sandstone; thickness 5 to 30 feet; occurs in lower half of formation; total thickness 300 feet in east, increases to 570 feet in west.

State	Maryland
Name	Clinton Group, including Rochester Shale
Geologic age	Silurian
Original map label	Sc
Primary rock type	shale
Secondary rock type	limestone
Other rock types	quartzite; sandstone
Lithologic constituents	Major Sedimentary > Clastic > Sandstone Sedimentary > Clastic > Mudstone > Shale Incidental Metamorphic > Metasedimentary > Metaclastic > Quartzite Sedimentary > Carbonate > Limestone
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	Cleaves, E.T., Edwards, J., Jr., Glaser, J.D., 1968, Geologic Map of Maryland: Maryland Geological Survey, Baltimore, Maryland, scale 1:250,000. Unpublished digital version of the Maryland state geologic map that was digitized by the USGS Water Resources Office in Towson, MD
Geographic coverage	Allegany - Washington