TY - JOUR

T1 - Radiolitid rudists

T2 - an underestimated archive for Cretaceous climate reconstruction?

AU - Schmitt, Katharina E.

AU - Huck, Stefan

AU - Krummacker, Malte

AU - De Winter, Niels J.

AU - Godet, Alexis

AU - Claeys, Philip

AU - Heimhofer, Ulrich

N1 - Funding Information: Acknowledgements. – We thank Christiane Wenske (LUH) for laboratory assistance. Financial support from German Research Foundation (DFG) project HU 2258/2-1 and HE 4467/8-1 is gratefully acknowledged. During this study, NdW was financed by a personal PhD fellowship from IWT Flanders (IWT700; now part of the Flemish Research Council, FWO). PC thanks the VUB strategic research fund and Research Foundation Flanders (FWO) for instrument funding.

PY - 2022/12

Y1 - 2022/12

N2 - Rudist shells are important archives for palaeoenvironmental reconstructions in the greenhouse world of the Cretaceous. Radiolitids, a family of rudists became very abundant dwellers of the shallow marine carbonate platforms during the Cretaceous. Still, due to the complex structure of their low-Mg calcite outer shell layer, radiolitids are often deemed unsuitable for palaeoenvironmental reconstructions. The aim of this study is to present a combination of petrographic (transmitted light microscopy and cathodoluminescence microscopy) and elemental analyses (high-resolution μXRF and stable isotope) to investigate radiolitid shells for diagenetic alteration and to make them accessible as an archive for environmental conditions during the mid-Cretaceous. Four Eoradiolitites shells were analysed in detail: two right valves (RV), a left valve (LV) with an articulated RV and an isolated LV. Three shell structure types have been identified, including a non-compact, compact and celluloprismatic types. The compact structure type was identified in the LVs while the other two types were observed exclusively in the RVs. Radiolitid shell material composed of the non-compact and the compact structure types can be used as palaeoenvironmental archives as it preserved seasonal signals in both, shell growth structure and isotopic records, while celluloprismatic shell structures are less suitable for reconstructions due to diagenetic alteration. The alternation of dark and light lamellae in both valves, RV and LV, provide information on the intertidal living habitat of the shell-producing organism and its life span.

AB - Rudist shells are important archives for palaeoenvironmental reconstructions in the greenhouse world of the Cretaceous. Radiolitids, a family of rudists became very abundant dwellers of the shallow marine carbonate platforms during the Cretaceous. Still, due to the complex structure of their low-Mg calcite outer shell layer, radiolitids are often deemed unsuitable for palaeoenvironmental reconstructions. The aim of this study is to present a combination of petrographic (transmitted light microscopy and cathodoluminescence microscopy) and elemental analyses (high-resolution μXRF and stable isotope) to investigate radiolitid shells for diagenetic alteration and to make them accessible as an archive for environmental conditions during the mid-Cretaceous. Four Eoradiolitites shells were analysed in detail: two right valves (RV), a left valve (LV) with an articulated RV and an isolated LV. Three shell structure types have been identified, including a non-compact, compact and celluloprismatic types. The compact structure type was identified in the LVs while the other two types were observed exclusively in the RVs. Radiolitid shell material composed of the non-compact and the compact structure types can be used as palaeoenvironmental archives as it preserved seasonal signals in both, shell growth structure and isotopic records, while celluloprismatic shell structures are less suitable for reconstructions due to diagenetic alteration. The alternation of dark and light lamellae in both valves, RV and LV, provide information on the intertidal living habitat of the shell-producing organism and its life span.

UR - http://www.scopus.com/inward/record.url?scp=85147036477&partnerID=8YFLogxK

U2 - 10.18261/let.55.4.4

DO - 10.18261/let.55.4.4

M3 - Article

AN - SCOPUS:85147036477

VL - 55

SP - 1

EP - 21

JO - LETHAIA

JF - LETHAIA

SN - 0024-1164

IS - 4

ER -