ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1991.tb00309.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Sedimentary basins in the Caribbean and adjacent areas are assessed in terms of the plate‐tectonic and paleogeographic history of the regions. Primary phases of development were rifting and passive margin development during Jurassic‐Cretaceous drift of North from South America; and the Late Cretaceous to Recent relative eastwards migration of the Caribbean Plate from the eastern Pacific area to its present position between North and South America.Two primary stratigraphic suites of rock occur in the Caribbean region: (I) autochthonous Jurassic, Cretaceous and Cenozoic passive margin sediments deposited along the rifted margins of North and South American basement: and (2) allochthonous oceanic crustal and magmatic arc rocks and overlying sedimentary units of the migrating Caribbean Plate. The tectonic boundary between these suites coincides roughly with the limit of circum‐Caribbean thrusted metamorphic/mafic rocks above the formerly passive Proto‐Caribbean shelf rocks (episutural foredeep basins), and juxtaposition youngs from west (latest Cretaceous in southern Yucatan) to east (late Neogene in Trinidad). Although Jurassic rift/early drift‐related source rocks occur in some areas. such as in Cuba—Bahamas. the primary source rocks in both suites were deposited well after rifting in the “medial” Cretaceous. Basin development during the Late Cretaceous to Recent tectonic juxtaposition of the two suites (i.e. Caribbean migration) directly controlled both clastic reservoir facies deposition and hydrocarbon maturation in many areas around the Caribbean. Basin development, source and reservoir rock deposition, and maturation of source rocks in all basins in the region can be directly related to plate‐tectonic evolution. A satisfactory understanding of the hydrocarbon potential of the Caribbean/northem South American province therefore requires a full appreciation of the region's plate

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1991.tb00310.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Oil and gas exploration in Cuba began with the discovery of the Motembooilfield in 1881. and some 25 oilfields have subsequently been discovered. the largest of which areBoca de JarucoandVaradero.Two oil‐bearing provinces are known: the Northern Cuban Province, which includes the overthrust belt; and the Southem Cuban Province, to the south of the overthrust belt, which includes a number of Cretaceous‐Tertiary basins.Rocks in the overthrust belt are intensely faulted and folded. with folds trending NE in western Cuba and NW elsewhere on the island. The Northern Cuban Province is about 1,000–kms long and 80– to 100–kms wide: sediments here are generally 10– to 12–kms thick. Seven overthrust surfaces have been identified by drilling, and correspond to different oil zones: thus, oilfields are characteristically located within different tectonic‐stratigraphic units.The Southern Cuban Province covers an area of about 60.000 sq. kms, and is composed of several basins. whose development was different from those to the north. Oil has been located in the Central Basin, where oilfields are present in positive structures, but not so far in any other basins here, although surface and subsurface oil seeps are comm

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1991.tb00311.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Sedimentary basins in the NE Caribbean Plate Boundary Zone are associated with the evolution of a Cretaceous to Early Tertiary island arc, and with carbonate banks which formed following cessation of volcanism in the Eocene to Oligocene. Neogene sedimentary basins are typically present where crustal blocks in the plate boundary zone have undergone divergence, with or without rotation. Cretaceous through Oligocene basins may also have formed during divergence between crustal blocks, although this is difficult to prove owing to limited exposure and subsequent tectonic deformation. Other basins are associated with localized overthrusting along the plate boundaries.Absence of source rocks and complicated and variable geothermal gradients make the area one of high risk for petroleum exploration. However. the paucity of data collected in the region allows for significant future discoveries, and the presence of minor seeps and traces of petroleum from two wells gives some hope. Finally, there is some evidence that seismic reflection amplitude anomalies may be associated with gas occurrences in the NE Caribbean, such that imaging of “bright spots” may prove to be a successful exploration t

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1991.tb00312.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

The island of Hispaniola (Dominican Republic and Haiti) lies within the North Caribbean strike‐slip plate boundary zone. The post‐Eocene history of Hispaniola is marked by strike‐slip accretion of crustal fragments onto a Late Cretaceous‐Eocene island arc.Three onshore Neogene clastic basins have been the focus of petroleum exploration in Hispaniola. Oil production was achieved by drilling sugace anticlines in the Azua Basin in South‐Central Hispaniola (Dominican Republic) during World War II (MalenoandHiguerito fields). More modem seismic exploration has been carried out in the Enriquillo, San Juan and Cibao Basins, but has not resulted in production.Recent surface and seismic stratigraphic mapping has elucidated the geoiogic history of Southem Hispaniola. It consists of several Late Cretaceous‐Eocene oceanic and island‐arc terranes separated by E‐Wto NW/SE‐striking “ramp” or thrust‐bound clastic basins of Neogene age (San Juan, Azua and Enriquillo). Basin edges are marked by either basinward‐verging thrust or reverse faults, or strike‐slip faults. Basin centres are characterised by gentle folds at shallow depths and high‐angle faults and associated folds at greater depths. The easternmost area of the three ramp basins (Azua and eastern Enriquillo) has been overprinted by more intense shortening caused by local NE‐ward “indentation” of the Beata Ridge, an area of elevated Caribbean sea‐floor south of Hispaniola.The stratigraphy of Southem Hispaniola is characterised by two depositional phases. During the first phase, deep‐water pelagic sedimentary rocks of Eocene to Middle Miocene age accumulated on the leading‐edge of the intra‐oceanic Caribbean Plate. Following Early Miocene transpressional juxtaposition of the intra‐oceanic plate with the Cretaceous‐Eocene island‐arc core of the island. Late Miocene‐Early Pliocene clastic rocks derived from the island‐arc core filled the developing Azua‐San Juan ramp basin system. In the Plio‐Pleistocene, shallow‐marine/lagoonal sediments filled the Enriquillo Basin, while residual fluvio‐deltaic sedimentation continued in the Azua Basin.Oil‐prone source rocks are predicted in deep‐water carbonate rocks of the Sombrerito Formation (Early Miocene) and hemi‐pelagic mudstones of the Trinchera Formation (Middle to Late Miocene). Reservoirs occur in carbonates of the Sombrerito Formation and sandstones of the Trinchera and Arroyo Blanco Formations.Maturity modelling shows that hydrocarbon generation largely pre‐dates Plio‐Pleistocene folding and uplift. Shallow. late‐formed structural traps in the Azua Basin have been charged by remigrated hydrocarbons. Unrecognised and undrilled deeper parent structures are predicted at depth in the Azua Basin, but require modem seismic data to confirm their existence. Existing seismi

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1991.tb00313.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Eleven wells were drilled in Jamaican territory over a 27–year period commencing in 1955: all were abandoned as dry. This study evaluates the island's petroleum potential in the light of new data on the source‐rock quality of the shales penetrated, and on reservoir properties of sandstones and limestones interbedded with these shales.Altogether. 270 representative shales and mudstones were sampled from the Cretaceous Windsor, Hanover and Sunderland Formations, and from the Eocene Richmond and Chapelton Formations. and subjected to standard organic‐geochemical analyses. Data on organic matter quantity, type and maturity indicate good potential for oil generation in the Chapelton Formation. The other formations analysed have<1.0% total organic carbon. comprising woody and coaly kerogens, with no potential for oil generation.Modal compositions of detrital grains were determined on sandstones sampled for reservoir quality evaluation from four formations. Provenance studies indicate derivation from a magmatic‐arc source, with volcanic lithic fragments and feldspars being the dominant constituents. This unstable mineralogy, combined with rapid sedimentation and location of sedimentary basins close to source areas, implies low porosity and permeability in these sandstones.Other considerations of trap availability, presence and extent of cap rocks. and the likelihood of any petroleum generated being preserved in view of Jamaica's active tectonic history since the Middle Miocene, suggest that conditions for the generation. accumulation and preservation of commercial deposits of petroleum probably may not have exist

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1991.tb00314.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Barbados island has risen above sea‐level in the last one million years as a pinnacle on the structural high of the extensive Barbados accretionary prism. The island provides by outcrop and many wells a glimpse of the structural history of the oldest and thickest realm of the prism, and a model for evolution of oil and gas in an accretionary terrane rich in quartz sanaktones and muddy temgenous and hemipelagic rocks that are moderately rich in organic substances. The island contains four major tectonostratigraphic units: basal complex of Eocene accretionary origin: prism cover: the Oceanic allochthon, of marly forearc basin strata, that was thrust over the basal complex and prism cover: and mud‐matrix mélange diapirs. Oil and gas are sourced chiefly from the basal complex at depths below 7 km, the minimum maturation depth. Oil reservoirs are in sandstones of the basal complex in fault‐fold structures. Seals are provided by mudstones of the basal complex and, more regionally, by thick, impermeable successions of prism cover and the Oceanic allochthon. Current oil reservoirs probably evolved mainly in Late Neogene time during a late stage of deformations. Oil reservoirs are best known in southern Barbados, in the Woodboume Trough, where sealing conditions were optimized.Barbados' marine territory also includes an extensive fold‐thrust belt for some 50 km west of the island. This belt includes rocks of both the Barbados accretionary prism and strata of the Tobago Trough forearc basin. The thrusting is due to the westward wedging of the prism into the forearc basin between roof and floor det

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1991.tb00315.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

The Maturin Basin of eastern Venezuela, including Trinidad. has produced approximately 9.5 billion brls of oil, and is the site of significant new discoveries at El FurrialandEl Carito. The present structural basin was formed by oblique compression during Oligocene to Miocene time, with the northem flank being a folded and thrusted terrane over‐riding the South American continental margin. This deformed northern flank extends into the subsurface to the basin axis, and includes the southern half of the onshore and offshore territory of the Republic of Trinidad and Tobago. The basin was infilled from west to east by deep‐marine shales, turbidites, pelagic oozes and deltaic sediments of Neogene age. Deltaic sands form the reservoirs of all the important oilfields in the basin. Oil occurrence on the northern flank of the basin is associated with thrust‐related structures in Venezuela and wrench‐related structures in Trinidad.There are many excellent prospects along the flanks of wrench‐related ridges with diapiric cores in the Trinidad and Tobago portion of the basin. Late Pliocene and Pleistocene deltaic sands shale‐out northwards in very thick aggradational lobes, enhancing the prospectivity of the southern flanks of these ridges. The prospectivity of the fold‐and‐thrust belt in Trinidad and Tobago is limited by the distribution of reservoir facies in pre‐Pliocene sediments. Candidates for non‐deltaic reservoirs are Miocene limestones, Oligocene sheet‐sands, Eocene turbidites and Cretaceous

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1991.tb00316.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1991.tb00317.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1991.tb00319.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY