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Tectonic relationships between forearc-basin strata and the accretionary complex at Bath, Barbados

1985; Geological Society of America; Volume: 96; Issue: 7 Linguagem: Inglês

10.1130/0016-7606(1985)96 2.0.co;2

1943-2674

R. Torrini, R. C. Speed, G. S. Mattioli,

Geological and Tectonic Studies in Latin America

Research Article| July 01, 1985 Tectonic relationships between forearc-basin strata and the accretionary complex at Bath, Barbados RUDOLPH TORRINI, JR.; RUDOLPH TORRINI, JR. 1Department of Geological Sciences, Northwestern University, Evanston, Illinois 60201 Search for other works by this author on: GSW Google Scholar ROBERT C. SPEED; ROBERT C. SPEED 1Department of Geological Sciences, Northwestern University, Evanston, Illinois 60201 Search for other works by this author on: GSW Google Scholar GLEN S. MATTIOLI GLEN S. MATTIOLI 1Department of Geological Sciences, Northwestern University, Evanston, Illinois 60201 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1985) 96 (7): 861–874. https://doi.org/10.1130/0016-7606(1985)96 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 RUDOLPH TORRINI, ROBERT C. SPEED, GLEN S. MATTIOLI; Tectonic relationships between forearc-basin strata and the accretionary complex at Bath, Barbados. GSA Bulletin 1985;; 96 (7): 861–874. doi: https://doi.org/10.1130/0016-7606(1985)96 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 island of Barbados exposes the crestal zone of the accretionary prism of the Lesser Antilles forearc. Tertiary rocks at Bath, Barbados, include four lithic suites: (1) inter-bedded volcanogenic and mainly calcareous pelagic rocks (the Oceanic beds), (2) radiolarite, (3) siliceous hemipelagic rocks, and (4) mélange. Suites 1–3 are in structurally discrete groups of fault packets; mélange occurs in apparently diapiric crosscutting bodies. The Oceanic beds occupy a pre-Pleistocene nappe complex that underlies much of Barbados. Radiolarite and hemipelagic rocks belong to a thick accretionary basal complex and constitute the relative autochthon to the Oceanic nappes. Fault rocks of the sub-Oceanic fault zone developed during emplacement of the Oceanic nappes. The lower portion of the tectonic stack is deformed in a major south-verging fold couple with wavelength of ∼250 m. Lower, early emplaced Oceanic nappes are restricted to the core of the major synform and are increasingly deformed with depth. Structures suggest easterly transport of Oceanic nappes and upward younging of nappe emplacement, indicating that the deformation of Oceanic beds propagated westward. The Oceanic nappes provided a seal to rising fluids; transport of nappes may have been facilitated by elevated fluid pressure beneath their sole thrust. Pre- and post-nappe folds record north-south shortening about shallow, west-plunging axes, consistent with folded accretionary strata elsewhere on Barbados. Deformation occurred under shallow nonmetamorphic conditions.The Oceanic beds are interpreted as being trapped outer forearc-basin strata that have been tectonically shouldered by the arcward migrating prism flank or crest. The hemipelagic and radiolarite suites may be offscraped abyssal-plain and trench-wedge accumulations. Paleogene-lower Miocene Oceanic strata were deposited at depths between 2.0 and 4.8 km. Middle Miocene Oceanic beds accumulated at shallower depths (1–1.5 km); thus, early Miocene was the probable time of inception of major uplift and arcward shouldering in the crestal zone of the accretionary prism. Accretion of the basal complex of Barbados probably occurred in late Eocene time. 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.