Limestone Belts of Westchester County, N. Y. 215 
able planes of bedding also near its south extremity. More- 
over, this noryte has a lighter-gray color and contains more ~ 
the mica schist and limestone, and thus exhibits an interme- 
diate character corresponding with its intermediate position. 
This stratification in portions of the noryte is also distinct a 
mile to the eastward of this locality on the same side of the 
limestone, at the point mentioned on page 194. 
The granitoid and gneissoid quartzyte of Peekskill looks 
much like true granite and gneiss; but its transition to bedded 
quartzyte shows what it in fact is; and this is confirmed by 
the examination of thin slices, the quartz in it proving to con- 
sist of an aggregation of grains just like a sandstone. (The 
transition of this granitoid quartzyte to schist or slate has been 
mentioned on page 24. 
These facts are all in favor of the conclusion that the noryte 
was once a stratum conformable to the Peekskill limestone 
The exception referred to is at the southwest extremity of 
the belt on the river. Here there lies against the eastern side 
of the limestone a great mass of grayish or brownish-blac 
rock of the Cortland series. It is mostly pyroxenyte, moder- 
a fine-grained variety ; and it contains, besides augite, a little 
hornblende, quartz, calcite, and apatite. But portions of 
the mass consist of coarsish hornblendyte; and a small part 
of micaceous augite-noryte ; and there are also broad and nar- 
row bands of very fine-grained black hornblendic mica schist, 
not showing well a schistose structure, part of which are con- 
formable in strike and dip with the beds of the limestone, 
while others are in other positions. All the material is ve 
pyrtrhotitic. Besides, it contains the remarkable limestone 
breccia, of which a portion three feet square is represented on 
page 202. 
This singularly constituted mass shows no appearance that 
looks like a subdivision into dikes or veins, except in the 
