270 ANNAL8 NEW YORE ACADEMY OF SCIENCES 



The coal above the shale is distorted seriously only in the lower por- 

 tion, where the wrinkling is complex on the easterly side, the dips some- 

 times reaching 70 degrees. The thicker coals on that side, in several 

 places, have lost their original structure and they are now in slabs, one 

 to three inches thick, extending continuously in the wall of two or even 

 three benches. The dips on the opposite side rarely exceed 40 degrees, 

 and the coals above the clay are less affected, but they are folded gently 

 and occasionally show petty faults. 



Within the fold of shale, the underlying coal has suffered materially. 

 An accurate measurement of this exposure cannot be given, as the wall 

 is sometimes diagonal to the dip and at others parallel to the strike; the 

 succession descending is 



Feet Inches 



1. Shale, argillaceous, much contorted 1 



2. Coal, irregular, much twisted 1 foot to 1 6 



3. Shale, argillaceous, drab, foliated like schist, has a 



coal streak midway 8 



4. Coal, many pockets of shale, much ironstone ; the shale 



is argillaceous, irregular and flaky 15 



5. Argillaceous shale ; this has its carina on the eleventh 



bench, but forks on the tenth and it is the roof of 



the underlying coal bed ; averages 4 



6. Coal 6 



7. Clay 1 



The coals are broken into wedges with polished and often rounded 

 surfaces. Exposures in this wall are complete down to the third bench; 

 as one descends, the effects of the crush become more complex, the coal 

 and shale are broken into large fragments and intermingled, until on the 

 third bench the material seems to be hardly worth removing. 



But northwardl}^, the condition becomes simpler. An exposure at the 



foot of the incline, on the level of the third bench, shows the decreased 



fold with these beds : 



Feet 



1. Coal, mined on the third bench, where it is wrinkled into a 



fold, which is distinct on the fourth and fifth benches 



2. Shale, argillaceous, dark, often with an almost cone-in-cone 



structure ; when blown down, it breaks into rudely cylin- 

 drical fragments with highly polished surface 4 



3. Coal and shale, rolled into laminae one eighth to one inch 



thick, with curved and polished surfaces 6 



4. Sandstone or sandy shale 5 



5. Coal 3 



6. Shale, apparently the upper light colored shale seen in the 



southern wall ; is sharply contorted on the westerly side of 



