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

Evaluating XRF Measurements in Wet and Dried Sediments from IODP Marine Cores in Guaymas Basin

Paper number: 17-10
Program: Technical Sessions
Time: 11:50 AM – 12:05 PM

Authors

Abstract

X-ray fluorescence (XRF) is an analytical tool in paleoceanographic and paleoclimatic studies due to its rapid and non-destructive nature; however, elemental signals can be significantly affected by sample preparation, matrix heterogeneity and water content. In this study, calibration methods for XRF analyses are developed and evaluated using an Avaatech Core Scanner and a Thermo Scientific Niton XL3t XRF analyzer, including certified reference materials and marine sediment samples from cores of Hole U1545A drilled during the International Ocean Discovery Program (IODP) Expedition 385 in the Guaymas Basin.

Eleven certified reference materials have been analyzed, including eight loose powdered standards and three pressed pellets standards, in order to assess repeatability, reproducibility, analytical precision and matrix effects for both instruments. In addition, fifty marine sediment samples from Hole U1546A, cores 1H-1 to 7H-4 (~0.3 to 56 m), covering an age range of ~1,000 to 42,000 cal years BP, will be analyzed in their original wet condition, then freeze-dried to determine water content, and finally pulverized and analyzed in dry condition as loose powder. Through this workflow, a systematic evaluation of the effects of moisture and grain size on elemental XRF responses will be conducted.

Analyses of the certified reference materials and marine sediment samples were conducted using 4 µm Ultralene® film and 4 µm polypropylene film. The samples were measured on the Avaatech Core Scanner at 10 kV with no filter and a 10 s count time, and analyzed in Mining Mode on the Thermo Scientific Niton XL3t XRF analyzer, targeting Al, Si, K, Ca, Ti, and Fe. Instrument accuracy was assessed based on these measurements.

The results of this study quantify instrumental performance and matrix effects, enabling the development of instrumental and matrix calibration strategies. Their application to wet marine sediments enables assessment of the impact of water content on elemental signals and thus validates the use of calibrated XRF data for reliable geochemical interpretation of marine sediment cores in paleoceanographic and paleoclimatic studies.

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

doi: 10.1130/abs/2026CD-410989

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