: 
T. N. Dale—Geology of Rhode Island. —- 287 
4 was formed by erosion of the softer beds. But this does 
not explain the presence of the coal-measures between the 
epidotic schists at 14 on the S.E. and the protogine at 44 on 
the N.W ust resort to the supposition either of 
Archzan Islands and shallows in the Carboniferous estuaries, 
or of a double system of faults or of folds followed by erosion 
of the softer beds. 
besides, the protogine at ‘the pier is not prevalent, the rock 
being more enerally micaceous than chloritic, whereas the 
pposite case exists at Newport and Conanicut. From the 
relative dip and position of the mica schists of Bonnet Point, 
etc., and of the gneiss, granite and protogine south, these mica 
schists would seem to overlie the latter, but if we consider 
them as “ pre-carboniferous ” a question as to their relations to 
the epidotic, chloritie and hornblendic schists, which in other 
sa Succeed the protogine, arises. They may provisionally 
Supposed as synchronous with these or as underlying them. 
In accordance with these views the accompanying geologi 
Map and section have been prepared. They continue west- 
ward, the map (Plate I), and the general section (Plate IIT), of 
the first paper,* and the following table enumerates an de- 
_ Scribes all the beds of the south end of Narraganset Bay in 
* The la “ : a: 
yers of “quartz and clay aggregate” in con with protogine i 
Mackerel Cove are more inclined ane in the section, and the overlying sideritic 
what like the beds of Dutch 
are § d to dip away 
in ease of the chloritic argillytes, in — 
of first paper, at the other side of the basin, 
hical possibility that these beds dip against the y 
i f ine in its center, and as the underly- 
ica schists (02). 
