17 Paleoceanography and paleoclimate of the Gulf of California and how they resonate with the evolution of other marginal seas

This session features studies on the climatic and marine history of the Gulf of California and its connections to the global climate and ocean system, utilizing multidisciplinary geological, micropaleontological, geochemical, and numerical modeling proxies.

Thursday, 23 April 2026
9:30 AM - 12:00 PM
LMH, Deli

Paleocene–Eocene hyperthermal events: paleoenvironmental evidence and climatic significance

Paper number: 17-1
Program: Technical Sessions
Time: 9:35 AM – 9:50 AM

Authors

Abstract

The Paleocene and Eocene epochs (66–33.9 Ma) are characterised by major geological, climatic and biological changes that led to a profound ecological reorganisation in both marine and terrestrial environments. During the Paleocene–Eocene boundary interval and the early Eocene, several hyperthermal events were recorded, including the Paleocene–Eocene Thermal Maximum (PETM or ETM1) and the Eocene Thermal Maxima (ETM2 and ETM3). These events were marked by large carbon emissions to the atmosphere, deoxygenation of surface and deep waters, ocean acidification, and variable increases in global temperature. These warming episodes constitute natural analogues for assessing the impacts of current climate change. This study aims to reconstruct palaeoenvironmental conditions through the correlation of the fossil record (nano- and microfossils) and biogeochemical techniques (X-ray diffraction —XRD—, X-ray fluorescence —XRF—, and stable isotopes), applied to sedimentary rocks of the Tepetate Formation. This geological unit forms part of the oldest marine and continental Palaeogene deposits in Baja California Sur (BCS) and is composed of shale, limestone and sandstone séquenles ranging from the Late Cretaceous (Maastrichtian?) to the middle Eocene. To date, outcrops dated from the late Paleocene to the early Eocene (NP9–NP10) have been identified, based on key calcareous nannofossil species such as Discoaster lodoensis, Sphenolithus primus and Tribrachiatus orthostylus. In addition, foraminiferal identification is currently underway, along with the preparation of shale, siltstone and sandstone samples for geochemical analyses. This project seeks to understand how global warming events disturbed the palaeolittoral environments of BCS, in order to provide information that contributes to improving regional and local climate projections, and to deepen our understanding of present-day climate dynamics and their possible future trends.

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

doi: 10.1130/abs/2026CD-411018

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