1893.] NEW YOKK ACADEMY OF SCIENCES. 201 



Martha's Vineyard, Nantucket, etc., as we now know tbeui, have 

 not been submerged since the final retreat of the ghicier, and 

 their separation into isL'uids by the submergence of the inter- 

 vening hxnd 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 histoiic 

 l^eriod. 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 Avhich 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 Avhich 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. KJl, Feb. 11, 1837. CoimuunicatiDii from 

 the Governor relative to tlie geoloj^ical survey of tlie State. Mnst Ann. 

 llept. 1st Geo). Dist., Wni. W. Mather, " Encroachment of tlio Sea,"' 

 pp. 74, 75. 



Assembly Document No. 200, Feb. 20, 183S, Same title and subject, 

 pp. 132, 133. 



"On Water Courses of Long Ifslantl." Elias Lewis, Ji. (Am. -Touni. 

 Sei. xiii., 112-14C.) 



" Certain Features of the Valleys or Water Cour.-es of Soutiiern Lonj,' 

 Island." Elias Lewis, Jr. (Am. Jourii. Sci. xiii., 21.5, 216.) 



* " Iloport on the Geology of Martha's Vineyard.' (7 "Ann. Rept. U. S. 

 Gool. Surv.. ■j%-8(i;i) 



'• The Geology of Nantucket." (Bull. No. 53, U. S. Geol. Surv.) 



