17 D6. Geochemistry (Posters)

Tuesday, 26 March 2019
8:30 AM - 5:45 PM
Big Basin/Kaw Nation Rooms

TEMPORAL VARIATION OF STABLE HYDROGEN AND OXYGEN ISOTOPES FOR PRECIPITATION IN STILLWATER, OKLAHOMA

Paper number: 17-4
Program: Technical Sessions
Time: 8:30 AM – 5:45 PM

Authors

Abstract

Stable isotopes of hydrogen (δ2H) and oxygen (δ18O) can be used to explore the relationships between the local climate and hydrological cycle. The δ2H and δ18O in precipitation forms the foundations from which to assess local hydrologic cycles. We collected precipitation from 2006-2008 in Stillwater (36oN05”17.4”, 97o08’48.0”W), north-central Oklahoma and analyzed them for δ2H and δ18O. Our objectives were to document the temporal variations in the δ2H and δ18O and to develop a local meteoric water line (LMWL) and to assess the processes that control the δ2H and δ18O composition over seasonal cycles. The results showed that the temporal δ2H and δ18O isotopic composition were more depleted in the fall and winter and more enriched in the spring and summer. The lower δ2H and δ18O isotopic composition in the fall and winter were due to precipitation under colder conditions and the more enriched values in the spring and summer are due to warmer temperatures. The δ18O and δ2H define an LMWL of 7.6753x+11.0192 (R2=0.9167), which has a slightly lower slope than that of the Global Meteoric Water Line (GMWL). The lower slope may be due to evaporation of rain during precipitation within this semi-arid environment or from a mixture of evaporated water from the terrestrial environment with precipitating air mass in Oklahoma. The LMWL for Stillwater will serve as a useful tool for future surface and groundwater studies conducted in north-central Oklahoma. Such studies, which involve the use of stable isotopes of hydrogen and oxygen, will help geologists and other scientists to couple geochemical processes with the hydrologic cycle.

Geological Society of America Abstracts with Programs. Vol. 51, No. 2

doi: 10.1130/abs/2019SC-326685

© Copyright 2019 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.