DOI: 10.1016/j.palaeo.2016.03.016
论文题名: Carbon cycle history through the Jurassic-Cretaceous boundary: A new global δ13C stack
作者: Price G.D. ; Fozy I. ; Pálfy J.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2016
卷: 451 起始页码: 46
结束页码: 61
语种: 英语
英文关键词: Carbonate carbon cycle history
; Chemostratigraphy
; Early Cretaceous
; Late Jurassic
英文摘要: We present new carbon and oxygen isotope curves from sections in the Bakony Mts. (Hungary), constrained by biostratigraphy and magnetostratigraphy in order to evaluate whether carbon isotopes can provide a tool to help establish and correlate the last system boundary remaining undefined in the Phanerozoic as well provide data to better understand the carbon cycle history and environmental drivers during the Jurassic-Cretaceous interval. We observe a gentle decrease in carbon isotope values through the Late Jurassic. A pronounced shift to more positive carbon isotope values does not occur until the Valanginian, corresponding to the Weissert event. In order to place the newly obtained stable isotope data into a global context, we compiled 31 published and stratigraphically constrained carbon isotope records from the Pacific, Tethyan, Atlantic, and Boreal realms, to produce a new global δ13C stack for the Late Oxfordian through Early Hauterivian interval. Our new data from Hungary is consistent with the global δ13C stack. The stack reveals a steady but slow decrease in carbon isotope values until the Early Valanginian. In comparison, the Late Jurassic-Early Cretaceous δ13C curve in GTS 2012 shows no slope and little variation. Aside from the well-defined Valanginian positive excursion, chemostratigraphic correlation durSchning the Jurassic-Cretaceous boundary interval is difficult, due to relatively stable δ13C values, compounded by a slope which is too slight. There is no clear isotopic marker event for the system boundary. The long-term gradual change towards more negative carbon isotope values through the Jurassic-Cretaceous transition has previously been explained by increasingly oligotrophic condition and lessened primary production. However, this contradicts the reported increase in 87Sr/86Sr ratios suggesting intensification of weathering (and a decreasing contribution of non-radiogenic hydrothermal Sr) and presumably a concomitant rise in nutrient input into the oceans. The concomitant rise of modern phytoplankton groups (dinoflagellates and coccolithophores) would have also led to increased primary productivity, making the negative carbon isotope trend even more notable. We suggest that gradual oceanographic changes, more effective connections and mixing between the Tethys, Atlantic and Pacific Oceans, would have promoted a shift towards enhanced burial of isotopically heavy carbonate carbon and effective recycling of isotopically light organic matter. These processes account for the observed long-term trend, interrupted only by the Weissert event in the Valanginian. © 2016. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68442
Appears in Collections: 过去全球变化的重建
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作者单位: School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus, Plymouth, United Kingdom; Department of Paleontology and Geology, Hungarian Natural History Museum, POB 137, Budapest, Hungary; Department of Physical and Applied Geology, Eötvös Loránd University, Pázmány P. sétány 1/C, Budapest, Hungary; MTA-MTM-ELTE Research Group for Paleontology, POB 137, Budapest, Hungary
Recommended Citation:
Price G.D.,Fozy I.,Pálfy J.. Carbon cycle history through the Jurassic-Cretaceous boundary: A new global δ13C stack[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2016-01-01,451