1893.] NEW YORK ACADEMY OF SCIENCES. 201 
Martha’s Vineyard, Nantucket, etc., as we now know them, have 
not been submerged since the final retreat of the glacier, and 
their separation into islands by the submergence of the inter- 
vening land is a comparatively modern phenomenon, due to the 
depression and erosion which are actively at work, and which 
have produced such conspicuous results during the historic 
period. Such a conception would bring the geology of the 
entire coastal region into harmony ; would imply a single series 
of causes and effects, and would not necessitate the introduction 
of any unusual or extraordinary phenomena in any particular 
locality. 
I have unfortunately not had the opportunity to visit either 
Block Island, Martha’s Vineyard or Nantucket, but from the 
published descriptions and the accounts which have been given 
me by those who have, besides the study of such material from 
these islands as I have had access to, has convinced me that the 
conditions there are entirely comparable to such as I am familiar 
with on Staten Island and Long Island, and that there is no 
necessity for invoking any other series of cause and effect, or 
of treating them, and the phenomena connected with them as 
isolated subjects ; such, for instance, as their special elevation 
by mountain making processes and other theories which have 
been advanced to account for the contorted condition of the 
strata on these islands. In this connection, reference should be 
made to the articles by Prof, N. S. Shaler*, but as previously 
intimated, these and several facts which have come to light 
since they were written, it is hoped will be discussed in subse- 
quent papers, 
Amongst numerous other published articles which refer to 
the region here considered may be specially mentioned the 
following : 
Assembly Document No, 161, Feb. 11, 1837. Communication from 
the Governor relative to the geological survey of the State. First Ann, 
Rept. Ist Geol, Dist., Wm. W. Mather, ‘‘ Encroachment of the Sea,” 
pp. 74, 75. 
Assembly Document No, 200, Feb. 20, 1838. Same title and subject, 
pp. 132, 133, 
*©On Water Courses of Long Island.” Elias Lewis, Jr. (Am. Journ, 
xiii., 142-146.) 
“Certain Features of the Valleys or Water Courses of Southern Long 
Island.” Elias Lewis, Jr. (Am. Journ, Sci. xiii., 215, 216.) 
Sci, 
— 
*“ Report on the Geology of Martha’s Vineyard.” (7 “Ann. Rept. U. 8. 
Geol. Surv., 296-363.) 
“The Geology of Nantucket.” (Bull. No. 53, U. S. Geol, Surv.) 
