Recent Advances in the Understanding of Northern Basin Stratigraphy, Gulf of Paria: Integrating Biostratigraphic and Palynological Analysis

Abstract

Abstract

The North Marine area is located in the East Central part of the Gulf of Paria, on the western coast of Trinidad. It is situated within the Eastern Venezuelan Basin, more specifically within the Maturin Sub Basin. The North Marine block is the result of the interaction of right lateral motion of the Warm Springs and Los Bajos Faults. 18 wells were drilled in the North Marine area and sub-commercial amounts of oil were produced from various wells. The lack of significant discoveries resulted in the acreage remaining idle for > 35 years. These existing wells contain a suite of geological analyses that were used for the re-evaluation of the area. The re-interpretation incorporates new analyses of High-resolution biostratigraphy including paleobathymetries, well log motifs, palynogical zonation, lithological and seismic correlations. The study is focused on the North Marine area which will develop a stratigraphic framework for Petrotrin's Marine acreage on the west coast of Trinidad. This stratigraphic framework will aid in building a relationship to define the Formations to the north and south of the Los Bajos Fault in the Gulf of Paria. The Northern Basin lithostratigraphic units range in age from the Early Miocene Manzanilla Formation to the Pleistocene Talparo Formation. Traditionally, it was noted that the Manzanilla Formation deposited in the Pliocene underlies the more argillaceous Springvale Formation and the top of which is bounded by the Pliocene-Pleistocene boundary. The Talparo Formation lies unconformably on the Springvale Formation and the sediments represent a gradual transgressive sequence.

The current re-evaluation illustrated some discrepancies, the Pliocene-Pleistocene boundary now lies within the Talparo Formation. The top and base of the Manzanilla Formation was reviewed and noted to range from Zanclean to Messinian respectively. The chronostratigraphic results were determined primarily by palynological events correlating within the Trinidad region which are prevalent within the Pleistocene-Pliocene and the Miocene intervals. The top of the Zanclean is a correlative 3.6Ma flooding surface event on the relative change of coastal onlap from Haq et al. (1987). The ultimate goal of this study is to focus on a stratigraphic revision and use these integrated results to assist in building a relationship with the Northern and Southern Basin stratigraphy.

AAPG Datapages/Search and Discovery Article #90260 © 2016 AAPG/SEG International Conference & Exhibition, Cancun, Mexico, September 6-9, 2016