The nature of the crust under Cayman Trough from gravity

View/ Open
Date
2003-01-21Author
ten Brink, Uri S.
Concept link
Coleman, Dwight F.
Concept link
Dillon, William P.
Concept link
Metadata
Show full item recordCitable URI
https://hdl.handle.net/1912/10689As published
https://doi.org/10.1016/S0264-8172(02)00132-0DOI
10.1016/S0264-8172(02)00132-0Keyword
Caribbean plate; Cayman trough; Continental margins; Gravity anomalies; Serpentinized peridotite; Slow spreadingAbstract
Considerable crustal thickness variations are inferred along Cayman Trough, a slow-spreading ocean basin in the Caribbean Sea, from modeling of the gravity field. The crust to a distance of 50 km from the spreading center is only 2–3 km thick in agreement with dredge and dive results. Crustal thickness increases to ∼5.5 km at distances between 100 and 430 km west of the spreading center and to 3.5–6 km at distances between 60 and 370 km east of the spreading center. The increase in thickness is interpreted to represent serpentinization of the uppermost mantle lithosphere, rather than a true increase in the volume of accreted ocean crust. Serpentinized peridotite rocks have indeed been dredged from the base of escarpments of oceanic crust rocks in Cayman Trough. Laboratory-measured density and P-wave speed of peridotite with 40–50% serpentine are similar to the observed speed in published refraction results and to the inferred density from the model. Crustal thickness gradually increases to 7–8 km at the far ends of the trough partially in areas where sea floor magnetic anomalies were identified. Basement depth becomes gradually shallower starting 250 km west of the rise and 340 km east of the rise, in contrast to the predicted trend of increasing depth to basement from cooling models of the oceanic lithosphere. The gradual increase in apparent crustal thickness and the shallowing trend of basement depth are interpreted to indicate that the deep distal parts of Cayman Trough are underlain by highly attenuated crust, not by a continuously accreted oceanic crust.
Description
This paper is not subject to U.S. copyright. The definitive version was published in Marine and Petroleum Geology 19 (2002): 971-987, doi:10.1016/S0264-8172(02)00132-0.
Collections
Suggested Citation
Marine and Petroleum Geology 19 (2002): 971-987Related items
Showing items related by title, author, creator and subject.
-
Monsoon hydrography and productivity changes in the East China Sea during the past 100,000 years : Okinawa Trough evidence (MD012404)
Chang, Yuan-Pin; Chen, Min-Te; Yokoyama, Yusuke; Matsuzaki, Hiroyuki; Thompson, William G.; Kao, Shuh-Ji; Kawahata, Hodaka (American Geophysical Union, 2009-08-29)We analyzed the high-resolution foraminifer isotope records, total organic carbon (TOC), and opal content from an Okinawa Trough core MD012404 in order to estimate the monsoon hydrography and productivity changes in the ... -
Earthquake swarms driven by aseismic creep in the Salton Trough, California
Lohman, Rowena B.; McGuire, Jeffrey J. (American Geophysical Union, 2007-04-10)In late August 2005, a swarm of more than a thousand earthquakes between magnitudes 1 and 5.1 occurred at the Obsidian Buttes, near the southern San Andreas Fault. This swarm provides the best opportunity to date to assess ... -
The origin of hydrothermal chlorite- and anhydrite-rich sediments in the middle Okinawa Trough, East China Sea
Shao, Hebin; Yang, Shouye; Humphris, Susan E.; Cai, Di; Cai, Feng; Li, Jiangtao; Li, Qing (2017-05-18)During the Integrated Ocean Drilling Program (IODP) Expedition 331, five sites were drilled into the Iheya North Knoll hydrothermal system in the Okinawa Trough (OT) — a back-arc basin characterized by thick terrigenous ...