Tertiary Paleogeographic Evolution of the Sureste Basin, Mexico

Juan I. Juarez Placencia¹, Marta Mata Jurado¹, and Santosh Ghosh^2
1 Pemex Exploracion y Produccion, Villahermosa, Tabasco, Mexico
² Geo-Strat Consulting, Kingston

The Tertiary sedimentary column in the Sureste basin, Mexico shows a gradual shallowing upward aggradational trend. A mud-rich bathyal environment with the development of slope and deeper water facies characterized the Paleogene-Lower Miocene paleogeography in the area. Dark organic-rich shales with abundant planktonic fauna are the dominant lithology. Debris-flows and breccias were deposited in the slope environment, derived from the adjacent carbonate platforms in the Chiapas range to the south. Pre-existing structural and geomorphic highs such as the Jalpa High and the Artesa-Mundo Nuevo detached Cretaceous carbonate platform also controlled sediment thickness variation and facies development.

Uplift of the Chiapas Massif, associated with the Chiapaneca orogeny (SB 11.7 M.a.), generated large volumes of terrigenous detritus, triggering rapid progradation of the platform during late Middle Miocene. A prominent sand-rich turbidite complex developed in the southwest sector of the study area during the Middle Miocene. During the end of Upper Miocene and partly the Pliocene, shelf and paralic environments dominated most of the area. The shallowing upward trend continued into the Plio-Pleistocene when the paleoenvironment became more deltaic to continental in nature and showed an aggradational stacking pattern.

Lithologically the Middle Miocene section consists of interbedded fine to medium sandstones and shales, whereas the Mio-Pliocene is mainly sandy in character. Grain size, in general, varies from very fine grained (distal turbidite facies) to coarse grained, to even gravel size in proximal turbidites and continental facies.

Neogene sandstones constitute good reservoirs, where significant potential still exists for discovering new hydrocarbon accumulations, comparable to those already found productive in several plays in the study area.