REPORT OF THE DIRECTOR I912 21 



On the east the gneissic spur is overlain by schist which west 

 of Pawling forms what is known as '' West Pawling mountain " 

 and farther north between the " Clove '' and the Dover valley 

 forms '' Chestnut ridge." This garnetiferous mica schist, at 

 places showing well-developed crystals of cyanite, is regarded as 

 the metamorphosed derivative of the " Hudson river " slates. 

 West of the *' Clove" it grades into grits, phyllites and slates. 



At Whaley pond is a patch of limestone known as the '' white 

 ledge " which is quite isolated from any other limestone out- 

 crops. It is overlain by a quartzite, very similar to the basal 

 quartzite and while clearly lying against the gneiss at places, ap- 

 parently grades upward into the schist and appears to be a mem- 

 ber of that formation. The relations of gneiss and schist along 

 the eastern margin of the spur are still obscure. 



Extending from the southern to the northern boundary of the 

 quadrangle through the townships of Patterson, Pawling and 

 Dover is the Dover-Pawling limestone valley. This has been 

 mapped as far north as Wingdale. The eastern and western 

 margins of the valley are irregular and in many places show a 

 confusion of schist and limestone patches of varying sizes in jux- 

 taposition and in such further relation as to suggest that they 

 are dismembered portions caused by disturbances from beneath. 

 Two miles north of Pawling at " Corbin hill " is a large patch of 

 gneiss which is believed to be an inlier of the Precambric rocks ; 

 a broken piece of the Precambric floor thrust up among the 

 younger rocks. It is bounded on the east, south and west by 

 hmestone and on the north by schist, and the field relations, as 

 thus far studied, favor the view that all the contracts are faulted. 

 The northwestern slope of the hill is heavily drift-covered. 



East of the Dover-Pawling valley, as far north as Wingdale, 

 the schist rises as a high mass of passes eastward into Connec- 

 ticut. 



SURFICIAL GEOLOGY 



In continuation of his previous observations, work was carried 

 on by Prof. H. L. Eairchild in the Hudson-Champlain valley. 



In the report for 191 1 (Museum Bulletin 158, pages 32-35), the 

 hypothetical glacial Lake Vermont of Woodworth (Museum 

 Bulletin 84) was provisionally accepted, and some high level 

 shore features about Covey hill and in the St Lawrence valley 

 were correlated with it. Some yet higher beach phenomena 



