386 The Urrra Devonian Deposits of Maryland 



glomerate. The pebbles are quite small, mostly rounded quartz but tliey 

 are neither flat nor very numerous and do not break with, a smooth 

 fracture. They either project from or drop out of the matrix so that in 

 appearance it differs from that of tlie conglomerates described from a 

 lower horizon in the formation. This horizon is considered as nearly, if 

 not quite, at the top of the Jennings formation, at which position a 

 similar conglomerate has been noticed in several other localities. 



Exposure on Green Glade Run. — Seven miles northeast of Oakland 

 a road passing over Green Glade Eun from the southeast to the northwest 

 crosses the belt of the Jennings formation and, although on the opposite 

 side of the glade there are scarcely any exposures, outcrops occur on the 

 lulls on each side of the run. 



No. 1. Exposures on the north and south road to the east of Green 

 Glade Eun and between the road leading to Altamont and the one to 

 Swanton. The outcrops are mostly very argillaceous olive shales stained 

 brown which weather to a rather yellowish color and readily decompose 

 into soil. There are but few arenaceous layers and no fossils were 

 found. 



No. 2. Outcrops by the side of the road up the hill to the west of 

 Green Glade Eun as far as Maryland Park Place consisting of olive to 

 yellowish-green argillaceous shales with some thin layers of sandstone on 

 which are a few poorly preserved fossils as Spirifer disjunctus Sowerby 

 and Chonetes scttulus Hall but these species are not abundant. The 

 rocks dip eastward but they are probably on the western side of the axis 

 and it is a reversed dip as is shown on the upper Deer Park Eoad north- 

 east of Oakland. On the Geological Map of the Piedmont Folio this 

 exposure is near the upper part of the Jennings formation. To the east 

 of the run some red argillaceous shales were noticed by the roadside. 



No. 3. By the road on the western side of the first hill to the west 

 of Green Glade Eun the rocks are dipping northwest and are composed of 

 micaceous greenish thin sandstones and arenaceous somewhat rusty sliales. 

 These sandstones contain some pelecypods and a few poorly preserved 

 specimens of Spirifer disjunctus Sowerby. The fossils, however, are not 

 abundant and on the road a little to the east and below this fossiliferous 



