Barbados: Architecture and implications for accretion

摘要: The island of Barbados exposes the crestal zone remarkably broad accretionary prism Lesser Antilles foreacrc. architecture is three-tiered: an upper arched cap Pleistocene reefs that record rapid and differential uplift island, intermediate nappes mainly abyssal or deep bathyal pelagic rocks, a basal complex whose lithotypes extend to substantial depth may be representative bulk western inner prism. exposed consists generally steeply dipping ENE NE-striking fault-bounded packets which contain rocks one three lithic suites: terrigenous (quartzose turbidite mudstone), debris flow, hemipelagic (chiefly radiolarite). Present but imcomplete rock dating indicates suites are age overlapping in Early Middle Eocene time. Deformation within systematic, pre- synfault, indicative shortening normal packet boundaries. A unit materials probably underwent local resedimentation Miocene recognized wells, its relationship uncertain. packet-bounding faults interpreted have been primary surfaces reactivated by later intraprism movements. Exposed sedimentary can successfully assigned contemporaneous depositional sites associated with prism: beds trench wedge was connected South American sediment sources, flow floor slope basin accumulations material derived from lower slope, Atlantic plain strata, outer forearc sites. decollement at base due arcward motion respect during progressive growth. Principal seems started, apparently abruptly, Miocene. Quaternary partly diapirism. Paleogene subduction created region occurred differently configured present one.