Stretching of the Leeward Antilles Island Arc
|Investigator:||Hans G. Avé Lallemant|
|Graduate Student:||Amanda Beardsley|
|Funding Source:||National Science Foundation|
The Leeward Antilles (LA) island arc consists from west to east of the Dutch ABC islands (Aruba, Curaçao, and Bonaire) and the Venezuelan islands (Las Aves, Los Roques, La Blanquilla, La Orchilla, Los Frailes, and Los Testigos). Generally, they are underlain by metamorphic basement, plateau basalts, and island arc basalts. Supposedly, the Caribbean plate and the LA arc collided with South America diachronously (initially in Paleogene time in the west, and in the east in the Miocene). Generally, the plate convergence rate in island arcs is partitioned in an arc-normal component (e.g., thrust faults), an arc-parallel component (e.g., strike-slip faults), and an arc-parallel stretching component (e.g., arc-perpendicular normal faults). The present study deals with brittle deformation structures in the islands; these structures are interpreted in terms of the oblique convergence between the Caribbean and South American plates. Samples are collected for zircon and apatite fission-track analysis so as to determine whether uplift of the islands is indeed related to the eastward passage of the arc parallel to the South American plate.
Beardsley, A., G, Sisson, V.B., Avé Lallemant, H.G., and Roden-Tice, M.K., 2006, Shallow level exhumation history of the Leeward Antilles, offshore Venezuela: Evidence from fluid inclusion analysis: Geological Society of America, Abstracts with Programs, v. 38 (7), 80–12, p. 209.
Beardsley, A.G., Avé Lallemant, H.G., Levander, A., and Clark, S.A., 2006, Oblique Collision of the Leeward Antilles, Offshore Venezuela: Linking Onshore and Offshore Data from BOLIVAR: American Geophysical Union Transactions (EOS), v.87 (52), T43D–1676.
Beardsley, A.G., and Avé Lallemant, H.G., 2005, Brittle deformation history and rotation of the Leeward Antilles island arc: EOS (Transactions American Geophysical Union), v. 86 (52), p.F1661, T11B–0387.
Francis, A.H., Avé Lallemant, H.G., and Sisson, V.B., 2005, Tectonic history of two disparate high-pressure, low-temperature metamorphic belts in the Motagua Valley, Guatemala: Geological Society of America Abstracts with Programs, v. 37 (3), p. 5.
Avé Lallemant, H.G.., Francis, A.H., Sisson, V.B., Hemming, S. R., Roden-Tice, M., Brueckner, H.K., Harlow, G.E., and Chiquín, M., 2005, Two jadeitite belts in the Motagua Valley fault zone, Guatemala: two subduction events or one subduction event with retrogression? Geological Society of America Abstracts with Programs, v. 37 (7), p. 67–68.