DOI: 10.1016/j.palaeo.2017.07.031
论文题名: Tropical seasonality in the late Campanian (late Cretaceous): Comparison between multiproxy records from three bivalve taxa from Oman
作者: de Winter N.J. ; Goderis S. ; Dehairs F. ; Jagt J.W.M. ; Fraaije R.H.B. ; Van Malderen S.J.M. ; Vanhaecke F. ; Claeys P.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2017
语种: 英语
英文关键词: Mollusc
; Palaeotemperature
; Rudist
; Stable isotope
; Trace element
; μXRF
英文摘要: Geochemical proxy records from calcite shells of bivalves constitute an important archive for the reconstruction of palaeoenvironmental conditions on sub-annual timescales. However, the incorporation of these trace element and stable isotope proxies into the shell is influenced by a multitude of physiological and environmental factors that need to be disentangled to enable reliable reconstruction of palaeoclimate and palaeoenvironment. In this study, records of multiple proxies in three bivalve taxa from the same late Campanian locality in Oman are used to study the expression of various geochemical proxies in relation to each other and to the palaeoenvironment. Micro-X-Ray Fluorescence mapping allows the localization, discussion and evasion of diagenetically altered parts of the fossil shells. X-Ray Fluorescence line scanning calibrated with Laser Ablation Inductively Coupled Plasma Mass Spectrometry is used to measure trace element profiles through well-preserved calcitic parts of the shells. Records of stable carbon and oxygen isotope ratios of shell calcite are combined with these high-resolution trace element concentration profiles to study sub-annual variations in shell chemistry and reconstruct changes in the palaeoenvironment of the bivalves on a seasonal scale. Spectral analysis routines are used to detect cyclicity in stable isotope (δ18O and δ13C) and trace element (Mg/Ca, Sr/Ca, S/Ca and Zn/Ca) records. Differences in seasonal expression between these chemical proxies and between individual shells are discussed in terms of the relative influence of palaeoenvironment and potential species-specific physiological effects. Stable oxygen isotope ratios between shells suggest a local palaeotemperature seasonality of 8°C around an annual mean of 28°C, with the shell of the rudistid Torreites sanchezi milovanovici yielding slightly higher average temperatures. The discussion of the application of various Mg/Ca palaeotemperature calibrations on Mg/Ca records in these bivalve species emphasizes the complexity of using trace element proxies in extinct bivalve species. It shows that long-term changes in Mg/Ca ratios in ocean water need to be taken into account and that Mg/Ca ratios in bivalves might be influenced by vital effects. Sr/Ca and S/Ca ratios in these fossil taxa are likely controlled by growth and metabolic rates of the shell, although an influence of local salinity on strontium-to-calcium ratios cannot be excluded. Sub-annual variations in zinc concentrations in shell calcite may reflect seasonal variations in palaeoproductivity and redox conditions in the water column. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68084
Appears in Collections: 过去全球变化的重建
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作者单位: Analytical, Environmental and Geochemistry (AMGC) Department, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium; Department of Analytical Chemistry (A and MS), Ghent University, Krijgslaan 281, Campus Sterre - S12, 9000 Ghent, Belgium; Natuurhistorisch Museum Maastricht (NHMM), Bosquetplein 7, 6211 KJ, Maastricht, The Netherlands; Oertijdmuseum De Groene Poort, Bosscheweg 80, 5283 WB Boxtel, The Netherlands
Recommended Citation:
de Winter N.J.,Goderis S.,Dehairs F.,et al. Tropical seasonality in the late Campanian (late Cretaceous): Comparison between multiproxy records from three bivalve taxa from Oman[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2017-01-01