Orogenesis and landscape evolution above the subduction-transform transition at the southeast Caribbean plate corner, Trinidad and Tobago

Orogenesis and landscape evolution above the subduction-transform transition at the southeast Caribbean plate corner, Trinidad and Tobago

Bibliographic Details
Main Author: Arkle, Jeanette C.
Language:English
Published: University of Cincinnati / OhioLINK 2019
Subjects:
Geology
Caribbean
Tectonics
Exhumation
Erosion
STEP fault
Geomorphology
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=ucin1571061691451314
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-ucin15710616914513142021-12-18T05:25:47Z Orogenesis and landscape evolution above the subduction-transform transition at the southeast Caribbean plate corner, Trinidad and Tobago Arkle, Jeanette C. Geology Caribbean Tectonics Exhumation Erosion STEP fault Geomorphology The southern end of the Lesser Antilles subduction zone is considered to be a type-locality of Subduction-Transform Edge Propagator (STEP) faulting, where lithospheric tearing facilities the transition from subduction of the South American plate to transform motion of the Caribbean plate. Regions where plate boundaries transition from subduction to transform motion are sites of complex tectonic and deformation processes that are not well understood. The shallow emergence of the islands of Trinidad and Tobago that sit directly above the southeast Caribbean plate corner provide a unique setting to investigate the influence of the plate transition on shallow crustal deformation. In this dissertation, I characterize crustal deformation of the mountains of Trinidad and Tobago to evaluate the influence of the STEP fault transition at southeast Caribbean plate corner on the tectonic and geomorphic evolution of the mountains. Crustal deformation is examined through time-scales between 106 –103 years and from crustal depths of ~10 km to the surface in the mountains of Trinidad and Tobago. Quaternary surface uplift rates are determined using optically stimulated luminescence ages from marine terraces in Trinidad’s Northern Range to evaluate spatial and temporal patterns of neotectonic activity along the southeast Caribbean plate boundary and yield uplift rates from to ~0.7–2 mm/a since 80 ka to the present. Geomorphic analyses and cosmogenic 10Be data from the Northern Range, Trinidad and Main Ridge, Tobago are used to constrain rates of hillslope erosion (ranging from ~6–167 mm/a), to identify controls on catchment erosion, and to investigate the steadiness or transience of the landscape with respect to tectonics and fluctuations of climate and sea-level during the Quaternary. The exhumation history of the Northern Range, Trinidad and eastern Paria Peninsula, Venezuela are constrained with analyses of apatite fission-track and apatite and zircon (U-Th)/He thermochronology and indicate phases of exhumation at rates from <0.1 to ~1.5 mm/a since the late Miocene. The integration of these data defines distinct syn- and post- collisional histories along the southeast Caribbean plate corner. Slow bedrock cooling and exhumation characterize Miocene oblique Caribbean-South American collision in Trinidad and eastern Venezuela. The temporal and spatial patterns of rock uplift and exhumation of the post-collisional history are consistent with the time-transgressive deformation produced by an eastward propagating lithospheric STEP fault. If uplift and exhumation in the study region are related to STEP kinematics, these data indicate that STEP faults and associated processes may be capable to exhume and uplift rocks on the order of several kilometers or more depending on local boundary conditions. The migration of deformation and exhumation over discrete time periods and spatial scales presents new empirical data for geodynamic models and is among the first datasets that documents the long-term (106 years) patterns of shallow crustal deformation associated with STEP plate corners. 2019 English text University of Cincinnati / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=ucin1571061691451314 http://rave.ohiolink.edu/etdc/view?acc_num=ucin1571061691451314 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Geology
Caribbean
Tectonics
Exhumation
Erosion
STEP fault
Geomorphology
spellingShingle Geology
Caribbean
Tectonics
Exhumation
Erosion
STEP fault
Geomorphology
Arkle, Jeanette C.
Orogenesis and landscape evolution above the subduction-transform transition at the southeast Caribbean plate corner, Trinidad and Tobago
author Arkle, Jeanette C.
author_facet Arkle, Jeanette C.
author_sort Arkle, Jeanette C.
title Orogenesis and landscape evolution above the subduction-transform transition at the southeast Caribbean plate corner, Trinidad and Tobago
title_short Orogenesis and landscape evolution above the subduction-transform transition at the southeast Caribbean plate corner, Trinidad and Tobago
title_full Orogenesis and landscape evolution above the subduction-transform transition at the southeast Caribbean plate corner, Trinidad and Tobago
title_fullStr Orogenesis and landscape evolution above the subduction-transform transition at the southeast Caribbean plate corner, Trinidad and Tobago
title_full_unstemmed Orogenesis and landscape evolution above the subduction-transform transition at the southeast Caribbean plate corner, Trinidad and Tobago
title_sort orogenesis and landscape evolution above the subduction-transform transition at the southeast caribbean plate corner, trinidad and tobago
publisher University of Cincinnati / OhioLINK
publishDate 2019
url http://rave.ohiolink.edu/etdc/view?acc_num=ucin1571061691451314
work_keys_str_mv AT arklejeanettec orogenesisandlandscapeevolutionabovethesubductiontransformtransitionatthesoutheastcaribbeanplatecornertrinidadandtobago
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