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NEW YORK STATE MUSEUM 



northeast of Middleburg. The opening was made in the upper 

 Marcellus black shale, just below a covering of coarse Hamil- 

 ton sandstone. The bed supposed to be coal is four feet thick. 

 It is a strongly carbonaceous shale much slickensided or broken 

 by the pressure of the overlying rock mass, which has caused a 

 certain amount of shearing movement within the mass. The 

 resultant product might be mistaken for coal by one who had no 

 knowledge of the mineral character of anthracite or bituminous 

 coals, but could hardly deceive the experienced. Other excava- 

 tions for coal have been made in this formation at Cobleskill, 

 Punch brook and near Middleburg. 1 



While thus the economic heritage of the Schoharie region is 

 chiefly derived from the Paleozoic age. the other ages of the 

 earth's history have also left their stamp on this district, and 

 the results of the dynamic activities during these later ages 

 have become potent factors in its industrial development. It 

 was during the Secondary or Mesozoic era of the earth's history 

 that the extensive denudation occurred which reduced this 

 region to the condition of a peneplain. Since this peneplain 

 bevels the strata, the lower beds, formerly buried under thou- 

 sands of feet of upper Devonic sandstones, became exposed and 

 thus accessible. The Tertiary or Cenozoic era witnessed the 

 cutting of the valley system which now dissects this ancient 

 peneplain, uplifted into a plateau, and which is the primary 

 element in the diversified topography of this district. Last of 

 all the Quaternary or Psychozoic era brought the ice invasion 

 thus covering the hillsides and uplands with the glacial drift, 

 which constitutes the soil of otherwise barren districts and 

 which also is the source of all the gravel sand and clay deposits 

 of the region. This same era, finally, has witnessed the advent 

 of man, and the wonderful changes due to him, at once one 

 of the weakest, and also one of the most powerful factors which 

 influence the development of the surface of the earth. 



1 Mather. Geol. 1st Dist. p. 323. 



