396 The Upper Devonian Deposits of Maryland 



the ridge in tlie edge of Oakland the rocks consist entirely of red argil- 

 laceous shales. This section along the road from Oakland toward Deer 

 Park is an excellent one for studying both the lithological characters and 

 fauna of the Jennings and Catskill formations. 



Exposures on Tro^d Run. — Mountain Lake Park on an east and west line 

 is near the middle of the Jennings belt which, to the south of the Little 

 Youghiogheny River, extends southwesterly into West Virginia. The 

 Jennings formation is flanked on each side by the Catskill formation, 

 in the same manner as from Mountain Lake Park northeast to Pennsyl- 

 vania. On the Jennings area well toward the West Virginia line are the 

 two localities known as Suimyside and Red House. 



About south of Mountain Lake Park is Trout Run, the lower course of 

 which is a sluggish stream, flowing through glades, without exposures of 

 rocks. On the ridges, however, on each side of the run are at first loose 

 blocks of stone and then ledges in place. 



No. 1. On the ridges along Troi;t Run are plenty of loose blocks 

 of the Jennings conglomerate and grit rock frequently mentioned in tlie 

 sections on the northern side of the river. On the ridge directly south of 

 the first Trout Run crossing are numerous large blocks of this conglom- 

 erate and grit which miist have, formerly, capped it. Under the con- 

 glomerate, apparently, are olive, mealy sandstones. The soil along the 

 highway contains numerous specimens of white quartz pebbles which 

 have come from the decomposition of the conglomerate. A part of this 

 coarser rock is similar to a typical coarse grit while other pieces contain 

 large numbers of quite large pebbles whicli are smooth showing that they 

 are water worn. Some of the white quartz pebbles are quite flat, suggest- 

 ing somewhat the flat pebbled conglomerates of the upper Chemung in 

 southwestern New York. There are also large clay pebbles which on 

 weathering leave holes in the rock resembling slightly the impressions of 

 fossil shells. The only fossils found, however, were impressions of wood. 

 No. 3. On the highway 3 miles south of Mountain Lake Park and 

 near the top of the second hill south of Trout Run, reddish shales show 

 in the gutters by the roadside. This is on the farm now owned by Mr. 

 Beekman, known as tlie "old Billy White place." Loose by the side of 



