A first look at oxygen isotope records from modern and Holocene‐aged gastropod (Stenomelania) shells from Lake Kutubu, Papua New Guinea

Abstract

The oxygen isotopic composition of Stenomelania gastropod shells was investigated to reconstruct Holocene palaeoclimate change at Lake Kutubu in the southern highlands of Papua New Guinea. Oxygen isotope (δ18O) values recorded in aquatic gastropod shells change according to ambient water δ18O values and temperature. The gastropod shells appear to form in oxygen isotopic equilibrium with the surrounding water and record a shift in average shell oxygen isotopic composition through time, probably as a result of warmer/wetter conditions at ca. 600–900 and 5900–6200 cal a bp. Shorter term fluctuations in oxygen isotope values were also identified and may relate to changes in the intensity or source of rainfall. Further δ18O analyses of gastropod shells or other carbonate proxies found in the Lake Kutubu sediments are warranted. © 2020 John Wiley & Sons, Ltd.

Matrix corrected SIMS in-situ oxygen isotope analyses of marine shell aragonite for high resolution seawater temperature measurements

“…Using both optical microscopy during SIMS sessions and subsequent BSE imaging offered a more confident identification of growth increments compared to previous strategies relying on literature-based growth rates (e.g., Böhm et al, 2000;Carré et al, 2005;Chamberlayne et al, 2021) or shell height measurements (e.g., Wanamaker et al, 2006). As the pulse-chase label is visible in high-resolution BSE images, it even surpasses the imaging resolution of fluorescent markers (e.g., Al-Qattan et al, 2023) and is therefore even better suited for marking narrow growth increments at high resolution as well as for species with inconclusive natural growth banding (e.g., Long et al, 2020). 4.2 Ion microprobe matrix calibration for obtaining quantitative δ 18 O from biogenic aragonite with organic-inorganic architectures:…”

Matrix corrected SIMS in-situ oxygen isotope analyses of marine shell aragonite for high resolution seawater temperature measurements

“…A desire for higher-resolution, in-situ microanalysis of δ 18 O in biomineral archives is driving instrumental development towards obtaining finer scaled paleoclimate and paleoenvironmental reconstructions (e.g., Green et al, 2022;Rollion-Bard et al, 2003;Vetter et al, 2013). Although these applications are becoming increasingly routine for some biomineral systems, quantitative in-situ applications to aragonite biominerals are hindered by a lack of suitable micro-analytical reference materials, and of analytical protocols and calibration methods for producing the requisite accuracy for paleotemperature calculations (He et al, 2021;Long et al, 2020;Rollion-Bard et al, 2007).…”