Cenozoic Kinematics and Dynamics of Oblique Collision Between two Convergent Plate Margins: The Caribbean-South America Collision in Eastern Venezuela, Trinidad and Barbados

Abstract

Numerous structural, tectonic, and geometric aspects of the Eastern South Caribbean Plate Boundary Zone are assessed or reassessed in the light of seismic reflection data, field studies from 2000-2007, heavy mineral analysis, updated interpretation of seismic tomography, seismicity, GPS data, and refined plate kinematic constraints for the Cenozoic. We show that the Cretaceous passive margin of northern South America was transformed to a north-facing, slowly convergent margin in the Late Maastrichtian, and that the collision between the Caribbean and South America was a collision of two convergent margins above an intervening, "doubly subducting" Proto-Caribbean oceanic lithosphere. The new assessments are iteratively integrated to create semi-quantitative palinspastic reconstructions for 5, 10, 25, 31 and 42 Ma, on which paleogeographies are developed. The origin of key sandstone units are considered, due to their importance as major reservoirs, as well as the implications of the kinematic and dynamic modeling for structural timing. The primary collision between the two plates was completed by 10 Ma, with subsequent motion being essentially E-W strike slip, the deformations of which are driven mainly in a bow-wave model of transcurrent simple shear.

Kinematic reconstruction of the Caribbean region since the Early Jurassic

“…We, as most authors, put faith in the oceanic spreading history of the Cayman Trough, even though the magnetic anomalies of the Trough are poor (Leroy et al, 2000). However, in conjunction with assessment of the 1000 km long west to east migrating foreland basins of northern South America (Pindell et al, 1998;Pindell and Kennan, 2007;Escalona and Mann, 2011), as well as the close match between the Cayman Trough's length and orientation and the Eocene-Recent motion history of North America relative to the hotspot reference frame to which the Caribbean Plate is fixed , see their Fig. 25), we are confident that the Cayman Trough does in fact record most (but not all; Sykes et al, 1982;Mann and Burke, 1990) of the Eocene-Recent displacement between the Caribbean and North American plates, which occurred in an E-W (~080°) direction relative to a stable North America.…”

Tectonic evolution of the Gulf of Mexico, Caribbean and northern South America in the mantle reference frame: an update

“…For example, it can be used to assess the southeastern Caribbean collision zone without the complication of having been dissected and offset 200 km by the east -west El Pilar transcurrent fault (e.g. Pindell & Kennan 2007b). Also, by retraction of transpression in the Chiapas Foldbelt of southern Mexico, the southern flank of the Tehuantepec terrane aligns with the SW Mexican Trench, restoring the smooth curvilinear transform trend along which the Chortís Block migrated since the Maastrichtian.…”

“…It may be that a tear in the slab was initiated along the Yucatán margin, which then progressively migrated eastward with continuing collision along the foot of the Belize margin (Pindell et al 2005), and eventually along the foot of the Bahamas Platform. Pindell & Kennan (2007b) interpreted the tomography of van der Hilst (1990) to suggest that the tear has reached Hispaniola at present. If this progressive tear model is correct, then there may be a very large remnant of the Proto-Caribbean slab accumulating in the mantle in a zone between the Colombian Basin and the Silver Plain.…”

“…The Maastrichtian -Palaeogene evolutionary interval (Figs 12 and 15-17) involves: (1) the cessation of Proto-Caribbean seafloor spreading by 71 Ma (Pindell et al 1988;Müller et al 1999); (2) northvergent inversion (potentially developing into south-dipping subduction) along the foot of the northern South American rifted margin (Pindell et al , 2006Pindell & Kennan 2007b); (3) the migration of the Caribbean Arc from the Yucatán-Guajíra 'bottleneck' to the Bahamas and western Venezuelan collision zones (Pindell et al 1988(Pindell et al , 2005; (4) the opening of the Yucatán (Pindell et al 2005) and Grenada (revised model proposed here) intra-arc basins as a means of the arc expanding into the Proto-Caribbean Seaway, which was wider than the Yucatán-Guajíra bottleneck, and maintaining collisional continuity with the American margins (Pindell & Barrett 1990); (5) the migration of Chortís-Nicaragua RiseJamaica along southwestern Mexico/Yucatán (Pindell et al 1988); (6) polarity reversal/onset of northward dipping subduction of Caribbean lithosphere at the Lower Nicaragua Rise, which we believe was the cause of arc magmatism in the eastward migrating Nicaragua Rise-Jamaica and took up the convergence between that terrane and the Caribbean Plate while the latter migrated northeast into the Proto-Caribbean Seaway (Pindell & Barrett 1990); and (7) the poorly-dated Eocene amalgamation of the Chortís and Panama -Costa Rica arcs into a single Middle American arc. Here, we will focus new considerations on the Motagua Fault Zone of Guatemala and the opening history of the Grenada and the Tobago basins.…”

“…(1) Southeast Caribbean: the linear Morón-Cariaco Basin-El Pilar -Gulf of Paria Basin fault system and additional splays through Trinidad crosscut the Middle Miocene foldthrust structures of Eastern Venezuela and Trinidad that had resulted from Caribbean collision of that age (Pindell & Kennan 2007b). The new (post-10 Ma) plate boundary configuration is also associated with a primary change in Late Miocene and younger deposition (Algar & Pindell 1993;Ysaccis 1997;Pindell et al 1998Pindell et al , 2005 Wadge & Burke (1983), Mann & Corrigan (1990) and Pindell (1993), wherein slices of Panama are being backthrust to the NW onto the Caribbean Plate, is not currently operating, although it probably did so earlier in the collision (Middle to Late Miocene).…”