4 Sedimentary Systems and Provenance in the Western Cordillera
This session invites contributions on sedimentary processes, depositional environments, stratigraphic frameworks, and provenance evolution across western North America. Topics may include basin analysis, source-to-sink studies, and applications of stratigraphy to energy and environmental questions.
Wednesday, 22 April 2026
8:00 AM - 12:00 PM
LMH, Fiesta Terrace Salon
Diagenetic Controls on Reservoir Properties of Salt-Influenced Miocene Deepwater Sandstones, Salina del Istmo Basin, Gulf of Mexico
Paper number: 4-12
Program: Technical Sessions
Time: 11:30 AM – 11:45 AM
Authors
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Sandra Guerrero Moreno Presenting AuthorUNAM- Facultad de Ingeniería, Ciudad Universitaria, 04510 Ciudad de México, México., Mexico
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Claudia Mendoza-RosalesUNAM-Facultad de Ingeniería, Ciudad Universitaria, 04510 Ciudad de México, México., Ciudad de México, CDMX
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Salatiel DiazUNAM-Posgrado en Ciencias de la Tierra, Ciudad Universitaria, 04510 Ciudad de México, México., Jojutla
Abstract
The southern Gulf of Mexico constitutes one of the largest hydrocarbon provinces in the world, with the Salina del Istmo Basin representing a major component of the petroleum system of southeastern Mexico. Miocene sandstones in this basin form important reservoir rocks, and their quality varies across minibasins as a function of depositional environment, sediment composition and provenance, climatic and tectonic settings, and diagenetic processes. While depositional environment, sediment provenance, and climatic conditions exert a first-order control on the primary composition and texture of sediments, salt tectonics has produced domes, diapirs, and related structures that may exert significant control on sandstone diagenesis. This study evaluates whether proximity to salt structures affects burial diagenesis in Miocene sandstones, compared to intervals located farther from diapirs, where diagenesis may instead be controlled by primary texture and burial-related processes. To test this, one hundred and fifty samples from four wells in the Salina del Istmo Basin were selected to encompass variations in texture, composition, burial depth, and proximity to salt-related structures. A multidisciplinary approach was applied, integrating petrographic analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), and digital image analysis using Fiji/ImageJ to quantify 2D porosity and pore network connectivity, placing rock-scale observations within the broader seismic-scale architecture of deepwater minibasins. Preliminary results indicate that Miocene sandstones represent the distal sink of a regional sediment-routing system mainly sourced from the Guatemala Suture and the Chiapas Massif complexes, as well as Miocene volcanism, supplying quartz-rich, metamorphic and ultramafic lithics, and volcanic detritus to deep-water minibasins. Facies associations include massive mudstones, thin-bedded very fine-grained deposits, and thick-bedded conglomeratic sandstones deposited in levee, overbank, and channel systems formed by low- and high-density turbidity currents and other gravity-driven processes in a deep-marine environment. SEM and cathodoluminescence imaging reveal a clay-rich matrix, framboidal pyrite, and a generally low abundance of carbonate and quartz cements, indicating limited early cementation. XRD analyses further constrain burial and thermal evolution through smectite-to-illite transformation and the presence of evaporitic minerals. Preliminary observations suggest that, despite proximity to salt structures, diagenetic alteration in several intervals remains relatively gentle, with preservation of primary porosity, indicating that reservoir quality may be largely controlled by original texture and sediment composition rather than by intense salt-related diagenesis.
Geological Society of America Abstracts with Programs. Vol. 58, No. 3
doi: 10.1130/abs/2026CD-411007
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