Lacustrine Carbonate Facies as Modern Analogues of Presalt Units of Northeastern Mexico

Abstract

During the last decade, the characterization of modern analogues of carbonate and clastic deposits have been of great relevance for oil exploration. Nowadays, microbial carbonates are the subject of intense theoretical and technical exploration in order to understand the genesis and to frame the exploration of ancient pre-salt reservoirs, especially those derived from lacustrine deposits. With a major emphasis in rift lacustrine deposits, three-dimensional organo-sediments known as microbialites, such as stromatolites and thrombolites, accrete and develop a 3D synoptic relief that can be related to the physicochemical factors of the depositional environment. As they grow, they a generate primary porosity at the micro, meso and macroscale level, which in turn may be modified by diagenesis or other biogenic factors, modifying. This work presents the microbial sediments of the alkaline crater lake of Rincon de Parangueo (RP), a Quaternary lacustrine setting that may be considered a good modern analogue of ancient pre-salt systems. RP contains thrombolitic bioherms with a characteristic clotted, laminated and cystoidal microfabric. In addition, RP contains laminated muddy structures that preserve a record of changing geochemical conditions, among them microbially-induced sedimentary structures. This recent volcano-sedimentary setting may bear comparison with older volcano-sedimentary deposits from northern Mexico originated after the continental fragmentation and the opening of the Gulf of Mexico at the beginning of Mesozoic. Non-marine volcano-sedimentary sequences are well-exposed in northern Mexico and, although the regional geology is mainly dominated by volcanic and siliciclastic deposits, carbonates are present in some localities of Huizachal Peregrina in Tamaulipas, Mexico, and in Aramberri, Nuevo Leon.

AAPG Datapages/Search and Discovery Article #90369 © 2020 AAPG Hedberg Conference, Geology and Hydrocarbon Potential of the Circum-Gulf of Mexico Pre-salt Section, Mexico City, Mexico, February 4-6, 2020