Seismic response of major regional unconformities in Atlantic Coastal Plain sediments at Smith Point, Virginia

Research Article| February 01, 1983 Seismic response of major regional unconformities in Atlantic Coastal Plain sediments at Smith Point, Virginia P. S. DYSART; P. S. DYSART 1Regional Geophysics Laboratory, Department of Geological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 Search for other works by this author on: GSW Google Scholar C. CORUH; C. CORUH 2Earth Science Faculty, University of Istanbul, Jeoflzik Bolumu Vezneciler, Istanbul, Turkey Search for other works by this author on: GSW Google Scholar J. K. COSTAIN J. K. COSTAIN 1Regional Geophysics Laboratory, Department of Geological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1983) 94 (2): 305–311. https://doi.org/10.1130/0016-7606(1983)94<305:SROMRU>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation P. S. DYSART, C. CORUH, J. K. COSTAIN; Seismic response of major regional unconformities in Atlantic Coastal Plain sediments at Smith Point, Virginia. GSA Bulletin 1983;; 94 (2): 305–311. doi: https://doi.org/10.1130/0016-7606(1983)94<305:SROMRU>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 As part of an evaluation of the acoustic response of relatively unconsolidated sediments of Cretaceous and younger age beneath the Atlantic Coastal Plain, a seismic-reflection survey was conducted in Northumberland County, Smith Point, Virginia. The seismic data were acquired by the VP1&SU VIBROSEIS crew using a single Y-1100 vibrator. The survey area is on the flank of a negative gravity anomaly centered east of Smith Point and covering much of Chesapeake Bay. The purpose of the study was to confirm the depth to, and the nature of, acoustic basement and to investigate the continuity of reflectors in the overlying sedimentary sequence. Seismic and drill-hole data from many sites in the northern Virginia and Maryland area provided a generalized stratigraphy from which to interpret the seismic data.Seismic data indicate an average basement depth of 950 m. Data quality is sufficient to identify two normal basement faults with displacements of 40 m and 15 m bounding a tilted basement fault block. The presence of a large negative gravity anomaly and the known high heat flow (64.9 mW/m2) at this location suggest that the basement rock type is granite.Analysis of velocity spectra reveals the presence of an indurated unit 90 m thick of Triassic(?) age overlying crystalline basement.Shallow reflections marking regional Eocene and Cretaceous unconformities can be correlated with lithostratigraphy at three drill sites in Northumberland County. 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.