MIDDLE MIOCENE TECTONICS AND ITS EFFECTS
ON LATE MIOCENE SEDIMENTATION IN THE TRINIDAD AREA

LLEWELLYN TYSON, BRIAN DYER,
STEPHEN BABB
Trinidad & Tobago Oil Co. Ltd.
Pointe-a-Pierre, Trinidad


The eastern extension of the Andean Orogenic Belt into Trinidad is known as the Northern Range. The Miocene culmination of orogenesis in Trinidad was a direct result of renewed collision between the South American and Caribbean plates. The internal belt or, "infrastructure" of this orogen is represented by the regionally metamorphosed rocks of the Northern Range. The external or foreland fold belt is represented by folded, but unmetamorphosed, Miocene to Lower Cretaceous sedimentary rocks, the deformation extending as far south as the present day Columbus Channel Syncline.
Middle Miocene tectonics produced a clear distinction between two (2) Sub-basins, a Northern and a Southern, the barrier separating the two being the incipient Central Range. The shallow Northern sub-basin became the site of typical molasses deposition in the Late Miocene. The Central Range was, initially, an area of significant erosion. With the establishment of shoal conditions, it became an area of biohermal sedimentation. The eroded material was shed southwards as boulder beds into the deeper-water (bathyal) Southern sub-basin. At the close of the Miocene, the shallowing of the Southern sub-basin was achieved by the infill of this foredeep with deltaic sediments from the Orinoco River.

Home | About Us | Links To The World  |  Publications | Upcoming Events |

Feedback | Executive Members | Geology |Teaching Resources| Virtual Field Trip

THE GEOLOGICAL SOCIETY OF TRINIDAD & TOBAGO
P.O. Box 3524, La Romain, Republic of Trinidad and Tobago, W.I.