Island arcs and their role in the evolution of the western Arabian Shield

Abstract

Research Article| August 01, 1984 Island arcs and their role in the evolution of the western Arabian Shield V. E. CAMP V. E. CAMP 1Deputy Ministry for Mineral Resources, c/o W.G.M. Ltd., P.O. Box 5219, Jeddah, Saudi Arabia Search for other works by this author on: GSW Google Scholar Author and Article Information V. E. CAMP 1Deputy Ministry for Mineral Resources, c/o W.G.M. Ltd., P.O. Box 5219, Jeddah, Saudi Arabia Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1984) 95 (8): 913–921. https://doi.org/10.1130/0016-7606(1984)95<913:IAATRI>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 V. E. CAMP; Island arcs and their role in the evolution of the western Arabian Shield. GSA Bulletin 1984;; 95 (8): 913–921. doi: https://doi.org/10.1130/0016-7606(1984)95<913:IAATRI>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 Two northeast-trending late Precambrian ensimatic island-arc systems in western Saudi Arabia are described. Each displays lithotectonic provinces that conform to those found in modern examples of plate convergence. The younger Hijaz arc system (800–700 Ma) contains a thick fore-arc sequence of Al Ays group turbidites overlying an accretionary prism of metamorphosed and fragmented volcanosedimentary rocks and associated ophiolites of the Farri group and the Al Hinu formation. The older Asir arc system (> 900–700 Ma) is exposed at a much deeper erosional level, in which only remnant arc and fore-arc deposits are present. It is identified in part by a frontal-arc assemblage of abundant dioritic intrusions and high-grade metamorphic rocks that are interpreted as a high-T-low-P belt. A mafic volcanic assemblage in the back-arc area appears to delineate an interarc basin situated between the At Ta'if frontal arc and a lithologically similar remnant arc west of Bishah.About 700 Ma ago, the Hijaz island arc collided with the Asir arc system along a southeast-dipping subduction zone now recognized as the Bi'r Umq–Port Sudan suture. Epeirogeny during this period led to the creation of an intramassif basin in the Hijaz arc system and an accretionary basin in the Asir arc system. These were filled by volcanic and shallow-water to continental molasse deposits of the Hadiyah and Fatimah groups, respectively. Continued convergence between 700 and 675 Ma ago resulted in development of the northeast-trending Samran fold belt. The collision event marks the cessation of an episode of southeast convergence that is interpreted as the initial phase in the progressive eastward evolution of the Arabian-Nubian Shield. 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.