Evolution of the Cretaceous Artesa Mundo-Nuevo Carbonate Platform, North-Central Chiapas, Southeast Mexico

Joan M. Spaw¹, J. Ricardo Alcantara², Hugo Pena Ramirez², and Victor M. De la Cruz Rivera<sup>2

1</sup>Core Laboratories, Petroleum Services, Houston, Texas
²PEMEX Exploracion y Produccion, Villahermosa, Mexico

The hydrocarbon-rich, Artesa Mundo-Nuevo Carbonate Platform, located in the northwestern portion of the Sierra de Chiapas fold and thrust belt in southeastern Mexico, is structurally complex; consequently, the geometry of the platform and its margins cannot be discerned based solely on seismic data. Cretaceous geologic models were derived from environmentally significant lithofacies contained in 173 cores from 37 wells. Potential reservoirs in these intervals were also evaluated.

The lack of a documented platform edge to the north and the similarity of facies in the Reforma-Jalpa area, located immediately to the north of the study area, suggest a connection between these areas/platforms throughout most of the Cretaceous. The southern boundary of the Artesa Mundo-Nuevo Platform is indicated by a lateral change to deep water lithofacies. The eastern margin was seen in cores (occurrence of deep water lithofacies) until the Late Cretaceous. The western boundary was not discerned from cores in this study. Where distinct margins have been discerned, it is likely they were the result of gravitational collapse from karstification and submarine erosion and, possibly, due to reactivation of older basement tectonic elements.

Seven major depositional environments are recognized in the Cretaceous section of the Artesa Mundo-Nuevo carbonate platform. These carbonate environments include: sabkha, tidalflat complex, inner platform, inner platform with organic biostromes of rudists, and oysters, outer platform margin with organic biostromes of corals, rudists and red algae and with grainstone shoals, platform slope with debris flows and grain flows, and open marine basin floor.

Controls on sediment distribution across the platform and the anatomy of the platform include sea level and accommodation space, structural control due to reactivation of basement tectonic elements, and collapse from karstification.

AAPG Search and Discovery Article #90080©2005 GCAGS 55th Annual Convention, New Orleans, Louisiana