MARYLAND GEOLOGICAL SURVEY 



CAMBRIAN AND ORDOVICIAN, PLATE XX 



FlG. I. TYPICAL EXPOSURE OF THE ECHINOSPHERITES BED OF THE CHAMBERSBURG LIME- 

 STONE SHOWING CHARACTERISTIC COBBLY EFFECT. RAILROAD CUT AT PINESBURG STATION, 



MARYLAND. 



FlG. 2. TYPICAL OUTCROP OF STEEPLY DIPPING CHAMBERSBURG LIMESTONE ALONG ROAD 

 BETWEEN PINESBURG AND PINESBURG STATION, MARYLAND. 



