Rare-earth element patterns in conodont albid crowns: Evidence for massive inputs of volcanic ash during the latest Permian biocrisis?
Rare-earth element patterns in conodont albid crowns: Evidence for massive inputs of volcanic ash during the latest Permian biocrisis?
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牙形刺白牙冠中的稀土元素模式：最近二叠纪生物危机期间火山灰大量输入的证据？
DOI：
10.1016/j.gloplacha.2012.09.001
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发表时间：
2013-06
影响因子：
3.9
通讯作者：
Liu, Yongsheng
中科院分区：
文献类型：
--
作者：
Gao, Shan;Zhou, Lian;Hu, Zhaochu;Liu, Yongsheng
为研究二叠纪生物大灭绝（LPME）后的环境变化，对中国南方两个二叠纪-三叠纪界线剖面（梅山和大峡口）牙形石生物磷灰石进行了稀土元素（REE）剖面的提取。REE浓度进行了测量，在白色冠，牙形石的组织学，是致密的，最不容易成岩蚀变，努力恢复海水稀土元素的签名。然而，稀土元素来源分析表明，研究样品中的稀土元素80-100%来自硅质岩源，推测研究剖面中存在丰富的粘土矿物。区间I（前LPME）表现出较低的稀土元素的浓度和明显不同的稀土元素分布模式比区间II（同步LPME）和III（后LPME）的研究部分。稀土元素“指纹”表明，后两个区间含有大部分来自火山粘土的稀土元素，具有低Eu/Eu* 和LaN/YbN，高Th/La比值的特征。在后LPME区间III的火山衍生稀土元素的存在表明，火山爆发继续喷出火山灰的边界危机后的一个延长的间隔，或者，也许更有可能的是，大量的火山灰沉积物落在陆地上的LPME缓慢侵蚀和运输到海洋环境。火山灰最有可能的来源是西伯利亚圈闭岩浆区。Ce/Ce* 比值在LPME附近为0.8-1.0，可能反映了从缺氧到缺氧的海水条件，尽管还不确定研究剖面中的Ce主要是氢源还是碎屑源。
Rare-earth element (REE) profiles were generated from conodont bioapatite for two Permian–Triassic boundary sections in South China (Meishan and Daxiakou) in order to investigate environmental changes following the latest Permian mass extinction (LPME). REE concentrations were measured in albid crowns, the conodont histology that is densest and least susceptible to diagenetic alteration, in an effort to recover seawater REE signatures. However, an analysis of REE sources demonstrated that 80–100% of REEs in the study samples were derived from siliciclastic sources, presumably the abundant clay minerals present in the study sections. Interval I (pre-LPME) exhibited lower ΣREE concentrations and distinctly different REE distribution patterns than Intervals II (syn-LPME) and III (post-LPME) of the study sections. REE “fingerprinting” suggests that the latter two intervals contain a large fraction of REEs derived from volcanic clays, characterized by low Eu/Eu* and LaN/YbNand high Th/La ratios. The presence of volcanically derived REEs in post-LPME Interval III indicates that volcanic eruptions continued to spew ash for an extended interval following the boundary crisis or, perhaps more likely, that substantial ash deposits that fell on landmasses during the LPME were slowly eroded and transported to the marine environment. The most probable source of this volcanic ash is the Siberian Traps magmatic province. Ce/Ce* ratios of 0.8–1.0 around the LPME may reflect suboxic to anoxic seawater conditions, although it is uncertain whether Ce in the study sections is mainly of hydrogenous or detrital origin.
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DOI：
10.1111/j.1751-908x.2002.tb00886.x
发表时间：
2002-01-01
期刊：
GEOSTANDARDS NEWSLETTER-THE JOURNAL OF GEOSTANDARDS AND GEOANALYSIS
影响因子：
--
作者：
Gao, S;Liu, XM;Hu, SH
通讯作者：
Hu, SH
最近二叠纪生物大灭绝前的华南海洋环境火山扰动及其生物效应
影响因子：
3.7
作者：
J. Shen;T. J. Algeo;L. Zhou;Q. Feng;J. Yu;B. Ellwood
通讯作者：
B. Ellwood
影响因子：
5.3
作者：
D. Peppe;P. Reiners
通讯作者：
D. Peppe;P. Reiners
影响因子：
2.3
作者：
N. Pearce;J. Denton;W. Perkins;J. Westgate;B. Alloway
通讯作者：
N. Pearce;J. Denton;W. Perkins;J. Westgate;B. Alloway
影响因子：
5
作者：
H.A Armstrong;D.G Pearson;M. Griselin
通讯作者：
H.A Armstrong;D.G Pearson;M. Griselin