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The Paleocene to lower Eocene Chicontepec Formation consists of submarine turbidites deposited in front of the developing Sierra Madre Oriental foldbelt in east-central Mexico. The majority of studied outcrops are characteristic of non-channelized outer-fan lobe and fan-fringe deposits, and their distribution suggests the presence of major fan systems in both the northwestern and southern portions of the Chicontepec basin. The Chicontepec records the initial uplift and erosion of Mesozoic carbonate platform units located to the west. The composition of Chicontepec sandstones changes through time in southern outcrops near the Teziudán massif, reflecting uplift and unroofing of the massif during the Paleocene.

Chicontepec sandstones are mineralogically immature with an average composition of Q17F10R73. The average lithic fraction consists of 83 percent carbonate rock fragments. 12 percent volcanic rock fragments, 4 percent chen, and 1 percent metamorphic rock fragments. The more distinctive carbonate rock fragments include dark, argillaceous lime mudstones and wackestones with pelagic Foraminifera; lime packstones containing fragmented red algae, miliolid Foraminifera, and ooids; and crystalline dolomite. These rock types indicate uplift and erosion of both basin and platform carbonate strata during the Paleocene. The dark, argillaceous lime mudstone and wackestone fragments, the most commonly identified carbonate rock fragment, and chert were likely derived from Upper Cretaceous strata to the west. Fragments of dolomite and fossiliferous lime packstones, some containing the miliolid Foraminifera Nummotoculina heimi, were most likely derived from the middle Cretaceous El Abra Formation. Easterly directed paleocurrent measurements preclude the Tuxpán Platform (Golden Lane) as a major source of carbonate detritus during the Paleocene. The abundance of volcanic rock fragments, bentonites, and andesine plagioclase all suggest that volcanic activity was coeval with Chicontepec deposition. Outcrops southwest of Poza Rica show an increase in quartz, metamorphic rock fragments, microcline, and dolomite from the western (presumably older) to eastern outcrops. This petrographic change also corresponds to an overall coarsening- and thickening-upward trend interpreted as submarine fan progradation. Both trends are likely related to uplift of the Teziutlán massif to the south that resulted in the partial unroofing of Mesozoic carbonate units, the erosion of middle Jurassic sandstones and Paleozoic metasediments, and northward fan progradation.

Some have estimated that Chicontepec sandstones contain up to 106 billion barrels of oil in place, but the thin-bedded nature of individual sandstones, pervasive carbonate cements, and interstitial clays combine to reduce porosity, permeability, and oil recovery. Belter reservoirs are expected near Poza Rica where thick-bedded, quartz-rich sandstones derived from the Teziutlán massif were observed to have better porosities than sandstones to the north.

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