Report of the Sub-Committee on Mesozoic. 
GEOKGE H. COOK, 
REPORTER. 
Beginning with the lowest, there are, — 
1. The Teiassic. On the Atlantic slope this is represented by 
the red sandstones of Massachusetts, Connecticut, New York, 
New Jersey, Pennsylvania, Maryland, Virginia, and North 
Carolina. It is recognized as being above the Paleozoic Group 
and below the Cretacic System, by its relative position in regard 
to these rocks on either side. By the few fossils of animal forms, 
it is recognized as occupying the same stage as the Keuper 
of Europe, though its fossil plants bear some affinity to the 
Jurassic of Europe. The rock material of the system is largely 
granitic, but varies from a very coarse conglomerate through 
sandstone to a fine and soft shale. It generally contains very little 
calcareous matter, though there is a heavy bed of calcareous con- 
glomerate on the northwest border of the formation in New 
Jersey and further southwest. It is even bedded, and its materials 
have been derived from the older rocks bordering it on either 
side, and these have given character to the rock formation of 
the Trias near them. Attempts have been made to subdivide 
the System, but the diiferent attempts do not agree, and there is 
need of much more study upon them. The System is remarkable 
for the abundance of eruptive rocks which are found in it. The 
thickness of the whole is variously estimated at from 1500 feet 
to 15,000 or more. The measurements are unsatisfactory on 
account of faults in the rock. The rocks mainly dip in one direc- 
tion and are but little curved or folded. 
There have been nearly a hundred persons who have written 
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