Limestone Belts of Westchester County, N. Y. 367 
and the limits assigned to it by him are here retained. 1 
found the limestone outcropping along the eastern half of the 
broad valley. The mean strike to the south is N. 10° E. ; and 
the same east of Armonk. The limestone exists in the lake 
and was quarried near the northeast when the water was quite 
low ; but I found there no place for observing the strike except- 
ing in the schists about the lake, where the rocks are greatly 
contorted (see the T-symbols on the map), as if situated about 
the end of a fold. 
Areas 24 and 25.—These areas, to the northeast of Byram 
Lake (first mapped by Percival), are both bow-shaped, but in 
opposite directions. No. 24 follows a valley along the head- 
waters of Mianus River, and No. 25, that of Stone Hill River. 
The limestone outcrops to the east of the village of Bedford 
show that the bend corresponds with a change in the strike of 
the beds. In the Stone Hill River belt the strike of the bed- 
ding, in its southwestern part, is N. 55° E., but in its eastern, 
N. 23° E., showing that the bow-shaped form of the valley and 
outcrop was determined by the direction of the i 
c. Northern Section of the County. 
Some of the areas in the northern part of the Middle section 
of the county have been shown to tend toward east-and-west 
in trend and in the strike of the beds. In the Northern sec- 
tion the larger part of the areas have approximately this abnor- 
mal course, the normal northeast trend existing only in a large 
eastern and in some of the northwestern areas. 
Areas 27 and 28, and the small areas in the Verplanck Penin- 
sula.—These areas have been described on pages 205, 215. I 
add here that while the rocks on the north side of the Cruger’s 
limestone (number 27) are mica schist, and micaceous gneiss 
with soda-granite, quartz-dioryte and various chrysolitic kinds, 
those on the south side are the ordinary gneisses of West- 
chester County, containing chiefly orthoclase with some triclinic 
feldspar, and vary in color from flesh-colored and grayish-white 
where the feldspar predominates, to black or grayish-black where 
mica (biotite) is abundant. Of the small limestone areas of the 
Verplanck Peninsula, No. 2 (see map on page 195) has black 
dioryte on its northeast side, but on the opposite, and plainly 
