Complutense University Library

Gravity modeling of the Muertos Trough and tectonic implications (north-eastern Caribbean)

Granja Bruña, José Luis and Muñoz Martín, Alfonso and Ten Brink, Uri S. and Carbó Gorosabel, Andrés and Llanes Estrada, Pilar and Martín Dávila, José and Córdoba Barba, Diego and Catalán, Manuel (2010) Gravity modeling of the Muertos Trough and tectonic implications (north-eastern Caribbean). Marine Geophysical researches . pp. 1-21. ISSN 0025-3235

[img]
Preview
PDF
1MB

Official URL: http://springerlink.metapress.com/content/1573-0581/

View download statistics for this eprint

==>>> Export to other formats

Abstract

The Muertos Trough in the northeast Caribbean has been interpreted as a subduction zone from seismicity, leading to infer a possible reversal subduction polarity. However, the distribution of the seismicity is very diffuse and makes definition of the plate geometry difficult. In addition, the compressive deformational features observed
in the upper crust and sandbox kinematic modeling do not
necessarily suggest a subduction process. We tested the hypothesized subduction of the Caribbean plate’s interior
beneath the eastern Greater Antilles island arc using gravity modeling. Gravity models simulating a subduction
process yield a regional mass deficit beneath the island arc
independently of the geometry and depth of the subducted slab used in the models. This mass deficit results from sinking of the less dense Caribbean slab beneath the lithospheric mantle replacing denser mantle materials and suggests that there is not a subducted Caribbean plateau beneath the island arc. The geologically more realistic gravity model which would explain the N–S shortening observed in the upper crust requires an overthrusted Caribbean slab extending at least 60 km northward from the deformation front, a progressive increase in the thrusting angle from 8 to 30 reaching a maximum depth of 22 km beneath the insular slope. This new tectonic model for the Muertos Margin, defined as a retroarc thrusting, will help to assess the seismic and tsunami hazard in the region. The use of gravity modeling has provided targets for future wide-angle seismic surveys in the Muertos Margin.

Item Type:Article
Uncontrolled Keywords:Caribbean plate, Muertos Trough, Gravity modeling, Retroarc thrusting
Subjects:Sciences > Physics > Geophysics
Sciences > Geology > Geodynamics
ID Code:11692
Deposited On:03 Dec 2010 08:59
Last Modified:06 Feb 2014 09:09

Repository Staff Only: item control page