’ 
290 . T. N. Dale—Geology of Rhode Island. 
after studying certain hornblendic and chloritie rocks in Rhode 
Island and Massachusetts, and examining the granite near 
Tiverton,* is disposed to assign them to the Montalban; and as 
is of weight here, but the metamorphic character of the whole 
series, including the coal-measures, should make us cautious in 
the application of chemical methods of classification which 
might be valid in a region where the Carboniferous beds had 
preserved their normal constitution. 
An analysis of 200 measurements of the dip at the south end 
of the bay yields these results: There are 12 different directions 
ofthe dip: A, W.N.W.-E.S.E.; A”, W.-E.; B, N.N.E.-S.S.W 
B’ N.E-SW.; B’, N-S; GC NN.W-SS.E. Of these, A”, 
aM, 
”, B’”’, varying but 22° one way or the other from A, B, G, 
may be attributed to minor causes, leaving three main flexures 
45°-90° apart. As none of the twelve dips are confined to the 
Pre-earboniferous beds the flexures must all have taken place, 
.N.W.-E.S.E. fissures which characterize the whole region, 
especially the quartzyte conglomerate.t Two main synclinal 
gard to their lithologieal character. As the same bed is often 
exed in several directions it is not easy to determine whether 
unconformable deposition took place anywhere. What appears 
like unconformity is often the result of lateral pressure an@ — 
faulting, but, as there is some reason to suppose that the proto- 
ne and associated schists in the center of the basin were above 
water in Carboniferous times, it seems probable that on their . 
borders the Carboniferous beds must lie unconformably, but. 23 
the highly metamorphic character of the protogine and the 
subsequent flexure of the entire series has obscured the evl- 
dences of it. The irregular vertical distribution of the mem 
bers of the Pre-carboniferous points either to flexures in those 
more ancient times, or to changes or differences in the character 
Eastern Massachusetts. Boston Society of Natural History, 
1880, pp. 107, 108, 127, 133, 134. 2 
+ Professor Ch. H. Hitchcock notes the complex dips at the coal mines, P- 
127. 
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