Clastic domains of sandstones in central/eastern Venezuela, Trinidad, and Barbados: heavy mineral and tectonic constraints on provenance and palaeogeography

Abstract

Current models for the tectonic evolution of northeastern South America invoke a Palaeogene phase of inter-American convergence, followed by diachronous dextral oblique col-

Magma source evolution beneath the Caribbean oceanic plateau: new insights from elemental and Sr-Nd-Pb-Hf isotopic studies of ODP Leg 165 Site 1001 basalts

“…For the slab-window model of Pindell et al to be correct, given the mantle source constraints outlined in this paper, it would require the 'highly fortuitous' arrival of a mantle plume directly below the slab c. 91 Ma. The 'Atlantic convection cell' invoked by Pindell et al (2006Pindell et al ( , 2009 in their slab window model is presumably of depleted MORB-source upper mantle composition (although they do not explicitly state this). They do however state 'we would expect the resulting lavas [from their slab window model] to have the Fig.…”

“…4a). This trace element evidence in combination with their depleted radiogenic isotope signatures rules out any subduction component whatsoever in the source region of these lavas and again poses a fundamental problem for the slab window model of Pindell et al (2006Pindell et al ( , 2009. It could be argued that, because the lavas from Site 1001/152 were erupted in the centre of the Caribbean Plate, they are derived from a mantle source region which is less likely to be contaminated by subduction-influenced mantle than CCOP lavas nearer the edge of the plate.…”

“…The near absence of a depleted MORB source mantle signature in the basalts of the Caribbean plateau in conjunction with the apparent long-term (.10 Ma) availability of a deep mantle-plumederived source region below the Caribbean severely calls into question most aspects of the slab window model (Pindell et al 2006(Pindell et al , 2009 for the origin of the Caribbean Plateau. For the slab-window model of Pindell et al to be correct, given the mantle source constraints outlined in this paper, it would require the 'highly fortuitous' arrival of a mantle plume directly below the slab c. 91 Ma.…”

“…We note, however, that if the source region invoked in their model is ambient upper mantle and not a deep mantle plume, then the magmas which are formed will not have an oceanic plateau geochemical signature. This represents a fundamental flaw in the slab window model of Pindell et al (2006Pindell et al ( , 2009.…”

Sedimentology and depositional model for the Early Miocene Oficina Formation in the Petrocedeño Field (Orinoco heavy-oil belt, Venezuela)

“…In the northern part of the Petrocedeño field additional sediment was supplied from the Guárico fold-and-thrust belt and from the Serranía del Interior (Rivero and Scherer, 1996;Rodriquez and Oswaldo, 1996;Pindell et al, 2009; his domain 4).…”