TRINIDAD EXPLORATION REPORT
Trinidad & Gulf of Paria: "piggyback" halite-dissolution basins (11-0Ma) on a long-lived foreland-basin thrust belt (Campanian-Recent)
by Roger Higgs
©Geoclastica Ltd 2005
The evidence for a subsurface, dissolving, "Carib Halite Formation" detailed in this report, plus major changes to the "Caribbean Oblique Collision Model", will affect Trinidad exploration on- and offshore, changing interpretations and predictions of subsidence history, paleogeography, structure/traps (décollement; dissolution collapse), seismicity (transpression; collapse), paleo-heatflow (high halite conductivity), evaporitic source rocks, seals, etc. Many new plays will arise. For example, the concept of a continentwide Proto-Caribbean Foreland Basin with dual (N- and S-derived) sand fairways is new, replacing the single, pre-Caribbean passive-margin fairway of the old model. Both N and S fairways host large/giant oilfields (e.g. Furrial in the S; Angostura, Brighton in the N), serving as analogues for future exploration. The N fairway, being confined to the thrust belt, is breached/eroded by uplift unless promptly buried by a halite-dissolution basin, as in Trinidad (on-/offshore). The southern, Furrial play is predicted low in the S Trinidad thrust pile. The supposed 12 Ma shift to transtensional motion, Paria pullapart, and resulting gross dextral palinspastic (paleogeographic) distortion of Trinidad, are incorrect: dextral slip in Trinidad is not only entirely transpressive, but also totals only 30 km, not 240 km (Caribbean motion 2 cm/yr for 1.5 m.y.), distributed among the Pilar and N Coast Fault Zones (085 trend), and possibly the Warm Springs Fault (060).
The report presents the Jurassic to Recent evolution of Trinidad, in greater detail than the more regional companion report on NW Colombia-Venezuela-Trinidad, meticulously presenting the diverse evidence for deep-halite dissolution (from outcrops, wells and seismic profiles; such evidence may include known sub-commercial metalliferous deposits, offering a new model for metals exploration) and for long-lived northern provenance (based on southward fining, olistolith compositions, cannibalization and heavy minerals). The report is a painstaking synthesis of the literature, with the added benefit of the author's 20 years of experience in the region, conducting outcrop and subsurface studies in Trinidad, Venezuela and Colombia. Numerous enigmatic Trinidadian formations are analysed and demystified (e.g. Sans Souci, Toco, "Cherrycake", Soldado, Plaisance).
The text integrates and interprets a vast amount of data, leading to the main conclusions above. Products include 14 tectonogeographic maps (Maastrichtian-Quaternary) and 5 tables of data (olistolith compositions, heavy minerals, known evaporite occurrences, halite-dissolution basins, and analagous basins worldwide).
With frequent bid-round and farmin opportunities in Trinidad, onshore and offshore, and the recently demonstrated continued potential for giant oilfield discoveries (e.g. Angostura, discovered 1999), no exploration company interested in this prolific petroleum province should be without this report, which both BP and BHP have bought.
161 pages, 5 tables, 45 figures.
Download list of contents (pdf 63 KB)
For price and partner-discount information, please call +44 7880 515748 or email RogerHiggs@geoclastica.com