Introduction. Evidence of unconformity in the deposits of the island of Marthas Vineyard has been pointed out by Professor Shaler* in two papers, to which this may be regarded as a sequel. Having familiarized myself with the evidence on this island, I examined Block island with the view of determining the extent of these erosion phenomena and endeavored to apply the methods of Irving and Van Hise in the correlation of the terranes which the several unconformities divide. As the most complete exposure of strata in these two islands is that of the Gay Head cliffs, I have taken that as a standard.
GAY HEAD CLIFFS. The topography of the Gay Head cliffs is exhibited on the accompanying contoured map (plate 16), which I am able to present through the courtesy of the Superintendent of the “United States Coast and Geodetic Survey. On this . . .
- © 1896 Geological Society of America