气候变化领域集成服务门户(CCPortal): Central Tethyan platform-top hypoxia during Oceanic Anoxic Event 1a

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DOI	10.5194/cp-15-1327-2019
	Central Tethyan platform-top hypoxia during Oceanic Anoxic Event 1a
	Hueter A.; Huck S.; Bodin S.; Heimhofer U.; Weyer S.; Jochum K.P.; Immenhauser A.
发表日期	2019
ISSN	18149324
起始页码	1327
结束页码	1344
卷号	15 期号:4
英文摘要	Short-term hypoxia in epeiric water masses is a common phenomenon of modern marine environments and causes mass mortality in coastal marine ecosystems. Here, we test the hypothesis that during the early Aptian, platform-top hypoxia temporarily established in some of the vast epeiric seas of the central Tethys and caused, combined with other stressors, significant changes in reefal ecosystems. Potentially interesting target examples include time intervals characterized by the demise of lower Aptian rudist-coral communities and the establishment of microencruster facies, as previously described from the central and southern Tethys and from the proto-North Atlantic domain. These considerations are relevant as previous work has predominantly focused on early Aptian basinal anoxia in the context of Oceanic Anoxic Event (OAE) 1a, whereas the potential expansion of the oxygen minimum zone (OMZ) in coeval shallow-water environments is underexplored. Wellknown patterns in the δ13C record during OAE 1a allow for a sufficiently time-resolved correlation with previously studied locations and assignment to chemostratigraphic segments. This paper presents and critically discusses the outcome of a multi-proxy study (e.g., rare earth elements (REEs), U isotopes, and redox-sensitive trace elements) applied to lower Aptian shallow-water carbonates today exposed in the Kanfanar quarry in Istria, Croatia. These rocks were deposited on an extensive, isolated high in the central Tethys surrounded by hemipelagic basins. Remarkably, during chemostratigraphic segment C2, the depletion of redox-sensitive trace elements As, V, Mo, and U in platform carbonates, deposited in normal marine oxic waters, record the first occurrence of basinal, organic-rich sediment deposition in which these elements are enriched. During the C3 segment, seawater oxygen depletion established on the platform top as indicated by the patterns in Ce=Ce∗ and U isotopes. Shifts in redox-sensitive proxies coincide with the expansion of microencruster facies. Segment C4 witnesses the return to normal marine reefal faunas on the platform top and is characterized by patterns in redox-sensitive proxies typical of normal marine dissolved oxygen levels. It remains unclear, however, if platform-top hypoxia resulted from the expansion and upwelling of basinal, oxygen-depleted water masses or if spatially isolated, shallow hypoxic water bodies formed on the platform. Data shown here are relevant as they shed light on the driving mechanisms that control poorly understood faunal patterns during OAE 1a in the neritic realm and provide evidence on the intricate relation between basinal and platform-top water masses. © Author(s) 2019.
语种	英语
scopus关键词	anoxic conditions; Aptian; deposition; dissolved oxygen; hypothesis testing; hypoxic conditions; oxygen minimum layer; shallow water; Tethys; trace element; water mass; Atlantic Ocean; Atlantic Ocean (North); Croatia; Istria; Anthozoa
来源期刊	Climate of the Past
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/146797
作者单位	Institute for Geology, Mineralogy and Geophysics, Sediment and Isotope Geology, Ruhr-University Bochum, Bochum, Germany; Institute for Geology, Leibniz University Hannover, Hanover, Germany; Department of Geoscience, Aarhus University, Aarhus, Denmark; Institute for Mineralogy, Leibniz University Hannover, Hanover, Germany; Climate Geochemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
推荐引用方式 GB/T 7714	Hueter A.,Huck S.,Bodin S.,et al. Central Tethyan platform-top hypoxia during Oceanic Anoxic Event 1a[J],2019,15(4).
APA	Hueter A..,Huck S..,Bodin S..,Heimhofer U..,Weyer S..,...&Immenhauser A..(2019).Central Tethyan platform-top hypoxia during Oceanic Anoxic Event 1a.Climate of the Past,15(4).
MLA	Hueter A.,et al."Central Tethyan platform-top hypoxia during Oceanic Anoxic Event 1a".Climate of the Past 15.4(2019).