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

NET PRIMARY PRODUCTIVITY OVER THE LAST 22,400 CAL YEARS BP IN THE GUAYMAS BASIN BASED ON COCOLITHOPHORE DATA.

Paper number: 17-3
Program: Technical Sessions
Time: 10:05 AM – 10:20 AM

Authors

Abstract

Net primary productivity (NPP) was calculated from sediment core U1549A of the International Ocean Discovery Program (IODP) in the Guaymas Basin, yielding an average of 1176.45 mgC m-2 day-1, indicating that the Guaymas Basin has been highly productive over the last 22,400 cal years BP. Other indicators, such as total coccolith abundance and the N ratio, confirm its high productivity. The NPP results were compared with several points in the eastern equatorial Pacific Ocean, showing that the NPP of the Guaymas Basin has been the highest. Furthermore, a gradual downward trend in NPP was observed during the study period, ranging from very high productivity conditions at the end of the glaciation to high/medium productivity conditions towards the present day. This trend coincides with that observed at the other points with which it has been compared. In addition, other indicators, such as total coccolith abundance and the N ratio, confirmed its high productivity and allowed the identification of three intervals in which the atmospheric and oceanographic context changed, influencing the coccolith association. These intervals can be characterized as follows: (I) Conditions of high productivity from ~22,400 to ~15,320 years cal BP; (II) A transition period with moderate productivity from ~15,320 to 11,200 years cal BP; (III) An environment that gradually moves towards more stratified conditions and less productivity from ~11,200 years cal BP to the present.

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

doi: 10.1130/abs/2026CD-410982

© Copyright 2026 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.