GEOLOGICAL SECTION OF NEW JERSEY 353 
similar in composition to phases of the Losee gneiss. They are also 
interlayered with both the Losee and Byram gneisses on a broad 
scale, and the Franklin limestones are similarly interlayered with the 
granitoid gneisses, so that these two sets of rocks—the dark Pochuck 
gneisses and the Franklin limestones—together seem to constitute a 
matrix holding the intrusive granitoid rocks in the form of relatively 
thin but extended plates. 
Though the Pochuck gneiss and the Franklin limestone are both 
regarded as older than the granitoid gneisses, the original relations 
between them are not determinable. 
Apparently the dark rocks were already foliated before they were 
invaded, because the interlayering of the granitoid materials is so 
regular that the presence of some structural control would seem to 
have been a necessity, but during this deformation the early texture 
of the rock was broken down, important addition or subtraction of 
elements may have occurred, and a later crystallization ensued con- 
temporaneous with the crystallization of the injected material. The 
forces causing flowage probably continued to operate after crystalliza- 
tion had begun, and practically until it was complete, so that the injec- 
tion of the granitoid material, the pressing out and kneading of the 
masses of the matrix, and the development of textural foliation in 
both were phenomena connected in origin with a single cause. 
The Franklin limestone locally retains traces of original stratifica- 
tion, showing its sedimentary origin, but the lamination observed — 
within masses of this rock is regarded mainly as a sort of flow structure 
developed through the crystallization of the limestone masses while 
they were being molded under the action of deforming stresses and 
at the same time traversed by mineral-charged waters derived from 
the invading Losee and Byram magmas. ‘The facts are believed 
to warrant the conclusion that the white limestones and the various 
gneisses with which they are associated, together with the ore-deposits 
which they inclose, crystallized in their present state and received 
their present forms as geologic masses during a single period of regional 
deformation. . 
PALEOZOIC FORMATIONS 
The Paleozoic rocks comprise representatives of the Cambrian, 
Ordovician, Silurian, and Devonian systems. They outcrop (a) in a 
