Research Article| November 01, 1951 GEOPHYSICAL INVESTIGATIONS IN THE EMERGED AND SUBMERGED ATLANTIC COASTAL PLAIN: PART VI: THE LONG ISLAND AREA JACK E OLIVER; JACK E OLIVER LAMONT GEOLOGICAL OBSERVATORY (COLUMBIA UNIVERSITY), PALISADES, NEW YORK. Search for other works by this author on: GSW Google Scholar CHARLES L DRAKE CHARLES L DRAKE LAMONT GEOLOGICAL OBSERVATORY (COLUMBIA UNIVERSITY), PALISADES, NEW YORK. Search for other works by this author on: GSW Google Scholar Author and Article Information JACK E OLIVER LAMONT GEOLOGICAL OBSERVATORY (COLUMBIA UNIVERSITY), PALISADES, NEW YORK. CHARLES L DRAKE LAMONT GEOLOGICAL OBSERVATORY (COLUMBIA UNIVERSITY), PALISADES, NEW YORK. Publisher: Geological Society of America Received: 23 Feb 1951 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1951, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1951) 62 (11): 1287–1296. https://doi.org/10.1130/0016-7606(1951)62[1287:GIITEA]2.0.CO;2 Article history Received: 23 Feb 1951 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation JACK E OLIVER, CHARLES L DRAKE; GEOPHYSICAL INVESTIGATIONS IN THE EMERGED AND SUBMERGED ATLANTIC COASTAL PLAIN: PART VI: THE LONG ISLAND AREA. GSA Bulletin 1951;; 62 (11): 1287–1296. doi: https://doi.org/10.1130/0016-7606(1951)62[1287:GIITEA]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract A seismic survey consisting of 12 reversed refraction profiles was carried out in the waters around Long Island. A 200-foot interval contour map of the crystalline rock surface is presented. This surface is approximated by a plane dipping gently south to southeast. Relief of the order of 200–300 feet is indicated. The mean velocity of sound in the basement rocks is 18,400 feet/sec. (5.6 km/sec.). Two other seismic horizons were identified, one termed unconsolidated sediments having a mean velocity of 5400 feet per second (1.65 km/sec.) and a second termed semi-consolidated sediments with a mean velocity of 6500 feet per second (2.0 km/sec.). The latter is found only to the south and southeast of Long Island. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.