50 G 5 . REPORT OF PROGRESS. I. C. WHITE. 



calities as the " Monkey Ledge f is from 40 to 60 feet 

 thick, averaging 50 feet ; is thin bedded usually, though 

 with occasional massive plates, and is enormously current 

 bedded, with numerous layers of conglomerate-sandstone 

 scattered through the mass at no regular intervals, usually 

 in thin plates, with white, rounded quartz pebbles, always 

 recognizable ; and it is usually noticeable by making cliffs 

 near the hilltops. It is the great mark and guide to the 

 geology of the basin." 



The Scranton Sandstone is well exposed along the rail- 

 road, about half a mile south of the depot, and in many 

 other places around. 



It is the first great pebbly Sandstone mass above the low- 

 est workable coal of the Scranton region, and easily recog- 

 nized by its extraordinary oblique lamination. 



Its color is dark gray, in portions almost black. 



It contains very numerous small white quartz pebbles. 



It makes the great cliffs of the east bank of the Lack- 

 awanna half way between Carbondale and Forest City. 



It may be seen again just south of Forest City ; but to tell 

 how much it has escaped erosion in that neighborhood 

 would require a minute survey. Probably this is the rock 

 of the bold ledge on the east bank of the Lackawanna just 

 above Forest City, extending around the mountain ; and it 

 is probably the first sand rock of the diamond- drill boring. 



The Forest City coal bed lies 20' to 30' beneath the base 

 of the Sandstone above described, and is the lowest work- 

 able anthracite bed at this end of the basin ; extensively 

 worked along Roaring run near Scranton ; and the only 

 workable bed at Forest City ; where the Hillside Coal and 

 Iron Company has a colliery, shipping 30,000 tons per an- 

 num over the Jefferson branch of the Erie railroad. 



Its average thickness is 5', according to Mr. Hines, thick- 

 ening occasionally to 6^, thinning frequently to 4' and 3', 

 and sometimes to nothing. 



Its usual roof is a dark slate ; in some places replaced by 

 a dangerous sandstone. 



An area of 70 acres has been mined out and there may be 

 as much left to mine ; all in the corner of Susquehanna 



