Late Tertiary and Quaternary Evolution of the Northeastern South American Margin

Lorena Moscardelli¹, Lesli Wood², and Paul Mann³

¹ UT Jackson School of Geosciences
Austin, TX
phone: (512)471-0328, fax: (512)471-0140, moscardellil@mail.utexas.edu
² Bureau of Economic Geology, Jackson School of Geosciences, The University of Texas at Austin
Austin, TX 
³ Institute for Geophysics, Jackson School of Geosciences, The University of Texas at Austin
Austin, TX

The goal of the present research is to integrate a significant dropcore and geotechnical core database with a comprehensive mega-merged 3D seismic data set for understanding the nature, history and mechanisms of basin development in mobile shale, tectonically active plate margin settings. Additionally to define the climatic and tectonic history of the northeastern South American margin and the influence that history has played in the development of the deep marine margin.

The deep marine margin of the Southeastern part of the Caribbean is situated along the obliquely converging boundary of the Caribbean and South American plates and proximal to the mouth of the Orinoco River. Major structural elements that characterize the deep water slope regions include: Large transpression fault zones, fault-cored anticlinal structures, shallow-rooted sediment bypass grabens, and normal and counter-regional faults. Seismic data reveals several erosional surfaces that form the boundaries of enormous and episodic mass transport complexes (MTC) that are characterized by chaotic, mounded seismic facies and map in a fan-like geometry. The study area is also characterized by significant gas hydrate deposits and significant extrusive mobile mud features.

The combination of conventional hydrocarbon resources and unconventional sources in the form of gas hydrates make this one of the premier exploration and development regions of the world. Results will improve our knowledge regarding 1) the impact of the climate and tectonics on basin development, 2) the nature and morphology of deep marine reservoirs, 3) morphology, driving mechanisms and impact of catastrophic debris flows in deep water settings.