34 NEW YORK STATE MUSEUM 



jected southward, the fault on the east of Vly mountain falls in line 

 with the scarp on the east of Bald hill (see plate 5). 



The gneiss inliers in Matteawan, south of the Glenham belt, are 

 also clearly faulted against the slates on the west. A long swamp 

 borders the northern one of these on the west, while on the north 

 it is in faulted contact with the slates. 



The relationship existing between the limestone and the gneiss 

 all along the eastern margin of the Glenham belt and the smaller 

 masses at the south, is far from plain. Although relatively small, 

 there is probably some stratigraphic displacement, in places at least. 



The Bald hill mass shows a still greater vertical displacement. 

 As now uncovered, the break is partly within the gneiss itself and 

 partly along a contact with the limestone, and probably in some 

 places with the quartzite. The slope of the gneiss is always very 

 steep and often precipitous. A moderate slope at the base, in 

 places, may be interpreted as that of the quartzite or the surface 

 from which it has been removed in late geological time. This kind 

 of slope usually changes abruptly to a sharp angle with the vertical 

 in ascending the mountain. The abundant talus at the bases of 

 these scarps is misleading and gives the appearance of a much 

 gentler slope than they really possess. The complementary result of 

 recession of the summits by weathering is also confusing. 



Apparently the overthrust which elevated the Bald hill mass 

 involved a larger area of the gneiss. It seems reasonable to explain 

 the faulted contact of the gneiss of the Mount Honness spur and 

 the Fishkill limestone on the northwest of it as primarily due to 

 this thrust. Later or simultaneous tension faulting dropped the 

 limestone east of Bald hill into its present position. A number of 

 scarp faces at different elevations along the northwestern slope of 

 the Honness spur in line with the strike of the gneisses, and visible 

 even in the season of foliage, mark tension strike faulting of dimin- 

 ishing intensity eastward from the great normal fault on the east 

 of Bald hill. 



The eastern face of Honness is marked by a rather conspicuous 

 normal fault scarp which diminishes and dies away to the south- 

 ward (see plate 6). The throw here was not so great as on the 

 east of Bald hill. 



Along the west side of the east road from West Fishkill Hook into 

 the mountains, is a drop fault of small displacement. It is marked 

 first by a cliff of the quartzite, but higher up the mountain it is in 

 the gneisses. 



