MISSISSIPPIAN. 



419 



The Hedges shale is described as a dark coal-bearing shale overlying the Piirs- 

 lane sandstone in the Meadow Branch syncline. Because of its soft and unresistant 

 character it is exposed in but few places. The best estimate of its thickness, obtained 

 from a section south of Devils Nose, is 170 feet. 



The Myers shale is distinguished by its bright-red color. The basal 60 feet is 

 composed of cross-bedded reddish-gray gritty arkosic sandstone. At the top thin 

 reddish-stained sandstone merges into the overlying Pinkerton sandstone. The 

 thickness is estimated at 800 to 900 feet. 



The Pinkerton sandstone appears in only two small areas, one at Pinkerton 

 Knob and the other in the northern part of Third Hill Mountain. At the base are 

 gray platy sandstone and white quartz conglomerate, with soft crumbly sandstone 

 above. The upper layers, however, are very massive cross-bedded coarse white 

 sandstone. The thickness of the formation on Pinkerton Knob is given as about 

 125 feet. 



Plant remains found in the Rockwell formation, the Purslane sandstone, and 

 the Hedges shale are definitely referred by White to the Pocono group of the Car- 

 boniferous, and the few fragments from the Pinkerton sandstone are tentatively 

 regarded by White as of the same age, certainly not younger than the Mississippian. 



No fossils were found in the Myers shale, but as it lies below the Pinkerton 

 sandstone, it is older than that formation. 



Stose quotes from Stevenson, Ashburner, and I. C. White four sections of the 

 Pocono and arranges them geographically from west to east, in comparison with a com- 

 posite section in the Meadow Branch syncline in the Hancock quadrangle, as follows : 



Summarized sections of the Pocono group. 



All the above sections show in general the following fourfold divisions; a lower group of 

 shales and soft sandstones, generally reddish in color where weathered; a middle heavy sand- 

 stone and conglomerate, usually cross bedded; a variable thickness of black shale with thin 

 coal seams and sandstone; and an upper series of shales, usually red, and thick sandstones. 

 The thiclmesses in the first three columns of the table correspond rather closely, the total thick- 

 ness varying from 1,365 to 1,442 feet. The Sideling HUl tunnel section is much thicker, all the 

 members except the top sharing in the increase. * * * 



It is concluded from the above comparison that all the Carboniferous strata now remaining 

 in the Meadow Branch Mountains are Pocono in age and correspond to the rocks in the Broad 

 Top coal field below the Mauch Chunk. * * * 



As pointed out by Stevenson, the tliickening of the Pocono eastward is progressive. From 

 300 feet in Laurel Kidge, Fayette County, the Pocono increases to 1,030 feet in the southeastern 



