Lithospheric magnetic mapping of the northern Caribbean region

M. CATALÁN, J. MARTÍN-DÁVILA

Abstract


A more complete crustal perspective of the northernmost part of the Venezuela Basin is provided by data from an international public database processed with new geomagnetic models (CM4) together with data from aeromagnetic surveys and from a recent marine cruise in areas offshore Puerto Rico and the Dominican Republic. The magnetic anomaly map set off three main domains: the North Atlantic plate, a narrow zone extending from the Dominican Republic to Puerto Rico-Virgin Islands, and the North Caribbean Plate. We focused mainly on the latter, applying the Euler deconvolution algorithm in the Venezuela Basin. Shallow and middle depth sources (located between 2km and 12km) are inferred to be the dominant sources (85%), while deep sources are located mostly in the Venezuela Basin, and scarcely appear in the Beata and Aves Ridges. We performed 2D+1/2 modeling on an eastwest transect, using Bouguer gravity and magnetic anomaly data to derive a more detailed crustal description of the northern part of the Venezuela Basin. The model suggests that in the Caribbean crust, long wavelengths (>200km) are controlled by variations in crustal thickness, whereas the intermediate ones (50-100km) are mainly controlled by variations in their magnetic properties. It also suggests the presence of a local anomalous body located in the east-west transect, between 487km and 560km, displaying a remarkable positive magnetization contrast (0.3 SI) with regard to the rest of the basin. This body shows a slight increase in density (3010kg/m3), and extends from the bottom of the UCL (Underplate Cumulate Layer) to a depth of 7.5km. We correlate it with the volcanic wedge reported by Driscoll and Diebold (1998).


Keywords


Caribbean plate; Magnetic anomaly; Poisson's theorem; Potential field

Full Text:

PDF


DOI: http://dx.doi.org/10.1344/105.000001872

Refbacks

  • There are currently no refbacks.




Geoscience e-Journals

 

Previous

 

Random

 

Next

 

List

 

Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike License.
Geologica Acta (ISSN-1695-6133)
Biblioteca de Geologia (UB-CSIC) | Facultat de Ciències de la Terra, Martí i Franquès s/n 08028 Barcelona | Spain
Phone: +34 93 403 19 89 | Fax: +34 93 402 14 21 | E-mail: geologica-acta@ictja.csic.es
RCUB revistesub@ub.edu Avís Legal RCUB Universitat de Barcelona