DYNAMIC STRATIGRAPHY WORKGROUP

Deltaic to estuarine regime change on the proximal paleo-Orinoco shelf, Morne L’Enfer Formation, Trinidad

 

People:

Ariana Osman, Ron Steel

 

Research question(s):

The outer shelf/shelf edge of the paleo-Orinoco shelf has been more extensively studied than the other components of the Orinoco margin. What is the character of delta-estuary cycles on the inner shelf of the paleo-Orinoco shelf margin?

 

Summary of work:

Outcrop and well-log data from the Late Pliocene Morne L’Enfer Formation, onshore Trinidad, was integrated to understand the distribution of facies within a genetic sequence of mixed wave/tide-influenced delta, sequence boundary, and tide-dominated estuary associated with the paleo-Orinoco river. Clear differences in sand quality show that the transgressive (estuarine) sands would form better hydrocarbon reservoirs than the underlying regressive (deltaic) deposits. The character of these proximal delta-estuary cycles, when compared and contrasted with shelf-edge deposits, provide data for a proximal to distal regime-change model for the paleo-Orinoco shelf.