DOI: 10.1016/j.palaeo.2014.07.005
论文题名: Discrepancy between Sr isotope and biostratigraphic datings of the upper middle and upper Miocene successions (Eastern North Sea Basin, Denmark)
作者: Eidvin T. ; Ullmann C.V. ; Dybkjær K. ; Rasmussen E.S. ; Piasecki S.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2014
卷: 411 起始页码: 267
结束页码: 280
语种: 英语
英文关键词: Danish Upper Oligocene-Miocene succession
; Strontium isotope stratigraphy
英文摘要: One hundred and fifty-six 87Sr/86Sr analyses have been performed on 129 samples from 18 outcrops and boreholes in Oligocene-Miocene deposits from Jylland, Denmark. These analyses were mainly conducted on mollusc shells but foraminiferal tests, Bolboforma and one shark tooth were also analysed.The main purpose of the study is to compare the ages of the Danish succession suggested by the biostratigraphic zonation on dinoflagellate cysts (Dybkjær and Piasecki, 2010) with the ages based on analyses of the 87Sr/86Sr composition of marine calcareous fossils in the same succession.Analyses of samples from the Danish Brejning, Vejle Fjord, Klintinghoved, Arnum, Odderup, Hodde, Ørnhøj and Gram formations gave ages between 25.7My (late Oligocene) and 10.3My (late Miocene). The Sr isotope ages from the lower part of the succession, i.e. Brejning to Odderup formations, agree with the age estimates based on biostratigraphy. However, the 87Sr/86Sr ratios of fossil carbonates from the middle-upper Miocene, Hodde to Gram succession consistently indicate ages older than those recorded by biostratigraphy. Post-depositional processes as an explanation for this offset are inconsistent with good preservation of shell material and little reworking. A palaeoenvironmental cause for the observed mismatch is therefore indicated.Search for geological events that could explain the older ages obtained by Sr isotope compositions have not led to any conclusions and we had recognised the same problem in earlier reports and communications. We conclude that this is a general and possibly global, middle-late Miocene problem that has to be reconsidered and explained geologically. © 2014 The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69242
Appears in Collections: 过去全球变化的重建
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作者单位: Norwegian Petroleum Directorate (NPD), Professor Olav Hanssens vei 10, P. O. Box 600, Norway; University of Copenhagen, Department of Geosciences and Natural Resource Management, Section of Geology, IGN, Øster Voldgade 10, Copenhagen K, Denmark; Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, Copenhagen K, Denmark; Geological Museum, Natural History Museum of Denmark, Øster Voldgade 5-7, Copenhagen K, Denmark
Recommended Citation:
Eidvin T.,Ullmann C.V.,Dybkjær K.,et al. Discrepancy between Sr isotope and biostratigraphic datings of the upper middle and upper Miocene successions (Eastern North Sea Basin, Denmark)[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2014-01-01,411