SC> NEW YORK STATE MUSEUM 



Chajrter 1 



f STRATIGRAPHY OF THE SCHOHARIE REGION 



General characteristics and extent of formations 



In the Schoharie region there are 20 well defined geologic 

 formations or terranes, 13 of which are differentiated in the 

 accompanying map. They comprise sandstones, shales and lime- 

 stones which succeed each other in a definite and ascertained 

 order, and the character, thickness and fossil content of indi- 

 vidual beds scarcely vary over the entire area under discussion. 

 A glance at the map shows that the oatcrops of these strata are 

 defiected in loops up the valley of each of the three principal 

 streams of the region, the Cobleskill, the Schoharie kill and the 

 Fox kiTl.^ Around the Schoharie valley, the loops of all the 

 strata appear complete on the map, around the Cobleskill valley 

 they are only partially complete, while none of the loops cross 

 the valley of Fox creek so far as shown on the map. The loops 

 of the Cobleskill and the Fox kill valleys would appear complete 

 if the map extended further west and east. The looping of the 

 outcrops is principally due to the fact that the strata all incline 

 or dip towards the southwest. Thus as we follow up the Scho- 

 harie valley or the Cobleskill valley, higher and higher beds 

 approach successively the plane of the valley and pass beneath 

 it, the cut edges of each bed on opposite sides of the valley 

 thus joining, where the bed and the valley floor intersect. In 

 the Schoharie valley, the slight southward rise of the valley 

 floor — from 611 feet at Schoharie (Gebhard bridge) to 634 feet at 

 Middieburg, or only 23 feet in four miles, i. e. 6 ft to the mile, 

 scarcely influences this looping of the strata edges which is here 

 almost wholly due to the dip of the strata. On the other hand, 

 the more rapid rise of the narrower valley floor of the Cobleskill, 



^The termination " kill " is the Dutch for stream or creek. This nieaning 

 is often lost sight of and the word creek added. Thus we have Cobleskill 

 creek, Catskill creek, etc. while on the other hand the word kill, formerly- 

 used, has often been replaced by creek, as Schoharie kill by Schoharie 

 creek. Fox kill by Fox creek, etc. 



