Title: Structural styles of an accretionary wedge south of the island of Sumba, Indonesia, revealed by SeaMARC II side scan sonar
Abstract: Research Article| October 01, 1986 Structural styles of an accretionary wedge south of the island of Sumba, Indonesia, revealed by SeaMARC II side scan sonar NANCY A. BREEN; NANCY A. BREEN 1Department of Earth Sciences and Institute for Marine Sciences, University of California, Santa Cruz, California 95064 Search for other works by this author on: GSW Google Scholar ELI A. SILVER; ELI A. SILVER 1Department of Earth Sciences and Institute for Marine Sciences, University of California, Santa Cruz, California 95064 Search for other works by this author on: GSW Google Scholar DONALD M. HUSSONG DONALD M. HUSSONG 2Hawaii Institute of Geophysics, University of Hawaii, Honolulu, Hawaii 96822 Search for other works by this author on: GSW Google Scholar Author and Article Information NANCY A. BREEN 1Department of Earth Sciences and Institute for Marine Sciences, University of California, Santa Cruz, California 95064 ELI A. SILVER 1Department of Earth Sciences and Institute for Marine Sciences, University of California, Santa Cruz, California 95064 DONALD M. HUSSONG 2Hawaii Institute of Geophysics, University of Hawaii, Honolulu, Hawaii 96822 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1986) 97 (10): 1250–1261. https://doi.org/10.1130/0016-7606(1986)97<1250:SSOAAW>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 Email Permissions Search Site Citation NANCY A. BREEN, ELI A. SILVER, DONALD M. HUSSONG; Structural styles of an accretionary wedge south of the island of Sumba, Indonesia, revealed by SeaMARC II side scan sonar. GSA Bulletin 1986;; 97 (10): 1250–1261. doi: https://doi.org/10.1130/0016-7606(1986)97<1250:SSOAAW>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 The accretionary wedge south of Sumba Island, Indonesia, is in the early stages of continent-island arc collision. Australian continental shelf sediments are being actively accreted to the Sunda arc at the Timor trough. We have correlated SeaMARC II side-scan images and bathymetry with 3.5-kHz and seismic-reflection profiles to construct a structural interpretation of this zone. Deformation is concentrated on the lower slope of the accretionary wedge, within 15 to 25 km of the thrust front, above which the strain rate appears to decrease abruptly. Three distinct structural styles are developed in the survey area. The characteristics of the easternmost region are (1) deformation in a fold-and-thrust geometry; (2) presence of mud volcanoes and mud ridges parallel to the thrust front, indicating elevated fluid pressure; and (3) the development of a long décollement extending 10 to 15 km from the thrust front. In contrast, the central region shows a more homogeneous thickening, resulting mainly from closely spaced faulting. Seaward-verging thrust faults and conjugate strike-slip faults are the main structures in this segment of the accretionary wedge. Mud volcanoes and a very long décollement are absent in the central region. We present a hypothesis in which structural style is controlled by the length of the décollement developed in front of the thrust front. Short, thick thrust sheets may favor uniform shortening, whereas long thin sheets may be unstable to buckling and deform by folding. High fluid pressure may facilitate propagation of the décollement. In contrast to the accretion occurring in the other two regions, the western part of the accretionary wedge is in the process of being indented and redeformed by a basement ridge. 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.
Publication Year: 1986
Publication Date: 1986-01-01
Language: en
Type: article
Indexed In: ['crossref']
Access and Citation
Cited By Count: 79
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot