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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 53 (1969)

Issue: 9. (September)

First Page: 2031

Last Page: 2031

Title: Geologic History of Nicaraguan Rise: ABSTRACT

Author(s): Daniel D. Arden, Jr.

Article Type: Meeting abstract

Abstract:

A study of Previous HitrefractionNext Hit-seismic velocity Previous HitdataNext Hit beneath the Caribbean Sea and nearby areas of the Atlantic Ocean reveals that the thickest crust is in the Antillean island belts and the Nicaraguan Rise. In the Nicaraguan Rise, the maximum thickness is about 22 km and is south of the present topographic crest. Isopach maps of total crustal thickness indicate that the Caribbean crust is intermediate between average oceanic and continental crust.

The oldest dated rocks in the Caribbean are Jurassic, a fact which is consistent with the idea that the region had its origin in early Mesozoic time as a result of rifting and subsequent drift between the American and Afro-European continental blocks.

Throughout Jurassic and Early Cretaceous time, the Nicaraguan Rise was a mobile belt associated with vast submarine lava flows and mafic intrusives. Volcanism gradually decreased during the Late Cretaceous. Terrigenous clastic and carbonate strata alternated with tuff, agglomerate, and mixed-origin volcanic-sedimentary units. The first phase of the Laramide orogeny occurred at the end of the Cretaceous, and it may have been at this time that a rift along the southern flank of the rise separated it from the Beata Ridge which now is south of Hispanola.

Normal Previous HitmarineNext Hit sedimentation--clastic and chemical--prevailed during the Tertiary. Islands emerged and sank as movement occurred between crustal blocks. Tectonism beginning in middle Miocene time markedly altered the topography and depositional pattern of the rise. The Cayman Trough rift formed as a result of left-lateral displacement of at least 250 mi. The Nicaraguan Rise was tilted southward, with the result that the topographic crest was shifted 50-100 mi north.

Recent geophysical work related to petroleum prospecting has aided in Previous HitinterpretingTop the structure and stratigraphy of the rise. Cross sections and a map of depth to magnetic basement are presented.

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Copyright 1997 American Association of Petroleum Geologists