Integrating high-resolution Sr/Ca and ultrastructural analyses of the Tridacna squamosa shell to reconstruct sub-daily seawater temperature variation

IF 2.6 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Palaeogeography, Palaeoclimatology, Palaeoecology Pub Date : 2025-02-01 DOI:10.1016/j.palaeo.2024.112663

Cornélia Brosset , Chengcheng Liu , Haotian Yang , Hong Yan , Bernd R. Schöne

{"title":"Integrating high-resolution Sr/Ca and ultrastructural analyses of the Tridacna squamosa shell to reconstruct sub-daily seawater temperature variation","authors":"Cornélia Brosset , Chengcheng Liu , Haotian Yang , Hong Yan , Bernd R. Schöne","doi":"10.1016/j.palaeo.2024.112663","DOIUrl":null,"url":null,"abstract":"<div><div>Modern and fossil bivalves record environmental variability in their shells in the form of chemical and ultrastructural properties as well as changes in growth rate. These proxy data can be placed in precise temporal context based on growth pattern analysis. Some species such as tridacnids grow particularly fast providing unique insights into environmental changes on the time scale of weather which opens new opportunities for paleoclimate research. Here, we assessed the potential use of the fluted giant clam (<em>Tridacna squamosa</em>) to reconstruct sub-daily sea surface temperature (SST) fluctuations from shell Sr/Ca ratios. Through a combined μm-scale analysis of shell Sr/Ca (NanoSIMS) and ultrastructure (SEM) it was possible to study shell material produced during daytime (growth increments) and nighttime (growth lines) separately. Unlike coarser resolution chemical analysis (LA-ICP-MS and ICP-OES), this approach revealed a significant positive correlation between SST and Sr/Ca during daytime (R<sup>2</sup> = 0.36, <em>p</em> < 0.001). The correlation further increased when the NanoSIMS data of several consecutive daily increments were combined to match the sampling resolution of LA-ICP-MS and ICP-OES data, i.e., four days to two weeks (R<sup>2</sup> of up to 0.86, <em>p</em> < 0.001). With an uncertainty of at least ± 1.5 °C, the applicability of the Sr/Ca thermometer remains limited considering that <em>T. squamosa</em> only occurs in ecosystems with minimal seasonal temperature amplitudes. Consistent daily Sr/Ca cycles were observed with local maxima at growth lines. This cyclic pattern was found even when the ultrastructure morphology varied or when the complex crossed-lamellar ultrastructure of the shell deviated from its typical configuration during extreme weather events. Therefore, Sr/Ca is likely not directly linked to the shell ultrastructure, but instead both properties are driven by underlying physiological factors.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"659 ","pages":"Article 112663"},"PeriodicalIF":2.6000,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Palaeogeography, Palaeoclimatology, Palaeoecology","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0031018224006527","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOGRAPHY, PHYSICAL","Score":null,"Total":0}

引用次数: 0

Abstract

Modern and fossil bivalves record environmental variability in their shells in the form of chemical and ultrastructural properties as well as changes in growth rate. These proxy data can be placed in precise temporal context based on growth pattern analysis. Some species such as tridacnids grow particularly fast providing unique insights into environmental changes on the time scale of weather which opens new opportunities for paleoclimate research. Here, we assessed the potential use of the fluted giant clam (Tridacna squamosa) to reconstruct sub-daily sea surface temperature (SST) fluctuations from shell Sr/Ca ratios. Through a combined μm-scale analysis of shell Sr/Ca (NanoSIMS) and ultrastructure (SEM) it was possible to study shell material produced during daytime (growth increments) and nighttime (growth lines) separately. Unlike coarser resolution chemical analysis (LA-ICP-MS and ICP-OES), this approach revealed a significant positive correlation between SST and Sr/Ca during daytime (R² = 0.36, p < 0.001). The correlation further increased when the NanoSIMS data of several consecutive daily increments were combined to match the sampling resolution of LA-ICP-MS and ICP-OES data, i.e., four days to two weeks (R² of up to 0.86, p < 0.001). With an uncertainty of at least ± 1.5 °C, the applicability of the Sr/Ca thermometer remains limited considering that T. squamosa only occurs in ecosystems with minimal seasonal temperature amplitudes. Consistent daily Sr/Ca cycles were observed with local maxima at growth lines. This cyclic pattern was found even when the ultrastructure morphology varied or when the complex crossed-lamellar ultrastructure of the shell deviated from its typical configuration during extreme weather events. Therefore, Sr/Ca is likely not directly linked to the shell ultrastructure, but instead both properties are driven by underlying physiological factors.

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

Palaeogeography, Palaeoclimatology, Palaeoecology 地学-地球科学综合

CiteScore

5.90

自引率

10.00%

发文量

398

审稿时长

3.8 months

期刊介绍： Palaeogeography, Palaeoclimatology, Palaeoecology is an international medium for the publication of high quality and multidisciplinary, original studies and comprehensive reviews in the field of palaeo-environmental geology. The journal aims at bringing together data with global implications from research in the many different disciplines involved in palaeo-environmental investigations. By cutting across the boundaries of established sciences, it provides an interdisciplinary forum where issues of general interest can be discussed.