13-12 Geological Forcing of Genomic Patterns in a Cordilleran Maar Lake: A Geogenomic Perspective from the Trans-Mexican Volcanic Belt

Session: Earth Life Sciences across the Cordillera

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Across the Cordillera, volcanic and tectonic processes generate extreme-for-life environments where geological dynamics directly regulate biological organization. The Rincón de Parangueo maar crater (central Mexico) provides a unique case study to examine how basin evolution, subsidence, and hydrological disruption imprint genomic patterns on a maar crater lacustrine ecosystem. This Quaternary volcanic maar system transitioned from a perennial alkaline lake to a desiccated, deforming basin following intensive groundwater extraction, producing rapid changes in stress regime, pore-fluid circulation, and geochemistry. Integrated geological analyses, including stratigraphy, sedimentology, mineralogy, and structural mapping, have documented long-term carbonate microbialite growth followed by recent deformation, subsurface mud mobilization, and gas migration linked to active subsidence. These geological transformations define sharp physicochemical gradients that structure biological communities. High-throughput sequencing of sedimentary DNA (16S and 18S rRNA) combined with ASV-based bioinformatic workflows reveals strong habitat filtering, high community modularity, and minimal taxonomic overlap across microbialites, microbial mats, hypersaline waters, sediments, and subsurface mud layers. Geogenomic patterns indicate that geological forcing, rather than biological dispersal, dominates community assembly, with genomic signatures reflecting mineral substrates, pore-fluid connectivity, and redox conditions. Predicted metabolic pathways suggest feedback between carbonate precipitation, methane generation, and sediment deformation. This study demonstrates how geological processes operating at the small basin scale are encoded in genomic datasets, highlighting geogenomics as a powerful tool to interrogate Earth–life interactions in Cordilleran volcanic systems and to interpret biogeological signals in the continental rock record. PAPIIT IG101325.

Geological Society of America Abstracts with Programs. Vol. 58, No. 3, 2026

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