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Neogene Sandstone Composition and Provenance, Southern Gulf of Mexico

Abstract

Petrographic analysis and description from conventional cores from the main Neogene sandstone units of the Southern Gulf of México basin, including 1928 point count analyses, allowed us to identify the sandstone composition of the main reservoir units on the sector. Two types of volcanic litharenites are present to the west; lithic arcoses and arcosic litharenites are the main compositions on the central portion, and calcarenites are the only composition present to the east. On the marine and continental sectors of the southern Gulf of México, six compositional families are present on the Neogene sandstones: (1) one group of rocks of intermediate and acid volcanic composition, located to the west of the southern gulf, have a Transmexican Volcanic Belt (TMVB) compositional affinity, and a (2) family of basic volcanic composition is mainly related to the Tuxtlas Volcanic Complex. (3) Lithic arcoses are the main composition present at the Salina Basin, which extends into the deep Gulf of México with a provenance related to the Chiapas Plutonic Complex, (4) arcosic litharenites are the main composition observed at the Macuspana and Comalcalco Basins, including their marine counterparts, the Chiapas Fold and Thrust Belt is the main source for these sandstones; (5) calcarenites are present in the proximities of the Yucatán platform, and finally a (6) Neogene calclithitic family is present along the Veracruz Basin, mainly derived from the Sierra Madre Oriental. For this last family, sandstone composition is volcanic rich at the north and northwest sectors, metamorphic rich-quartz poor at the west, and metamorphic and quartz rich at the south and east sectors; these petrographic variations on the Veracruz Basin, illustrate local influence of different sources of sediment, such as the TMVB, the Cuicatlan Metamorphic Complex, and the Mixtequita Plutonic and Metamorphic Complex respectively.