--> Abstract: Caribbean Plio-Quaternary (5-0 Ma) Plate Interaction and Basin Development, Colombia-Venezuela-Trinidad Oil Province, by Roger Higgs; #90078 (2008)

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Caribbean Plio-Quaternary (5-0 Ma) Plate Interaction and Basin Development, Colombia-Venezuela-Trinidad Oil Province

Roger Higgs
Geoclastica Ltd, Marlborough, United Kingdom

Merida Andes NW-SE bivergent thrusting formed dual foreland basins (Maracaibo, Barinas) on the E-verging Catatumbo-Apure foreland basin. This uplift began near 5 Ma, based on (1) published fission-track ages (< 4.9 Ma), (2) the Pliocene early-fill age (Betijoque, Rio Yuca), and (3) Miocene age of uplifted Catatumbo remnants (La Cope, Mucujun). Uplift reflects SE-subducting Caribbean Plateau choking the S Caribbean Fault (Santa Marta-Guajira sector), also uplifting Santa Marta, Perija and Falcon. Resistance to all this shortening eventually forced a plate-boundary jump to the Ibague-Guaicaramo-Bocono-Sebastian-Pilar-C Range fault linkage. The Caribbean Plate thus annexed the N Andes (including "Maracaibo block") and adopted today's relative motion (2 cm/yr toward 085; GPS). Ensuing transpression at the Sebastian-Pilar sector (080; raised beaches) is masked where the coastal mountains (formed by prior Proto- and Caribbean oblique convergence; see companion abstracts) are collapsing by dissolution of thick (km), unproven, buried rift halite, forming Neogene basins (Carupano; Gulfs of Barcelona, Paria), reflecting long-term heavier rain since Panama-Colombia collision blocked Pacific-Caribbean oceanic circulation (13 Ma), initiating the Gulf Stream. The boundary jump was ca. 2.5 Ma, based on: (1) late Pliocene accelerated uplift shown by E Cordillera palynology and Quaternary gravels flanking the Merida Andes; (2) removal of the Maracaibo block from the path of Cura nappe SE obduction by restoring it 50 km W (2 cm/yr since 2.5 Ma). Hence the block does not "escape" N; strike slip on the Bocono dextral thrust is only apparent and minor (50 km sine 045); (3) 50 km of E-W extension (seismic estimate) in the Pilar-C Range stepover (superimposed on dissolution subsidence); and (4) straightening (NW-SE) of the E Trinidad shelf edge by restoring 50 km slip on the C Range Fault.

 

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas