Sulfur-isotope study on the mass extinction boundaries

大灭绝边界的硫同位素研究

• 批准号: 04804066
• 负责人: KAJIWARA Yoshimichi
• 金额: $ 1.47万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04804066/
• 关键词: Mass extinction; Sulfur isotopes; K; T boundary; P; Tr boundary; Oceanic anoxia; Stratified ocean; Isotope effect; Bacteria; 生物大量絶滅; 酸化還元条件; バクテリア同位体効果; 古環境

Systematic sulfur isotope data for whole-rock sulfides have been obtained from the chert-dominated, continuous, pelaqic sedimentary sequences spanning the Permian/Triassic (P/Tr) boundary at Tenjinmaru in the chichibu Terrane and at Sasayama in the Tanba Terrane in Japan. The P/Tr boundary is characterized by the occurrence of siliceous shales in association with a carbonaceous black mudstone which is similar in appearance to the worldwide distributed Cretaceous/Tertiary (K/T) boundary claystone. The obsarved data ciearly demonstrate a significant bimodalism. The 34S/32S ratios with respect to CDT are generally low throughout the Hiddle Permian (ca.-39 to -25 %.) and show a remarkable increase beginning in the lower Upper Permian and persisting into the Lower Triassic (ca.-20 to -2 %.), with a temporary and drastic negative shift, down to roughly the same isotopic level as in the Hiddle Permian, just at the suspected P/Tr boundary (ca.-41 to -23 %.). Interestingly, the mode of isotopic excursion across the P/Tr boundary is in striking contrast to that across the K/T boundary which was recently disclosed at Kawaruppu in Hokkado, Japan. The apparent extent of fractionation, with rospect to contemporaneous seawater sulfate, in the high-34S/32S grouplies within the range of -25(〕SY.+-.〔)10 %, which is quantitatively equivalent to the currently confirmed range of kinetic isotope effect during bacterial dissimilatory sulfate reduction, and that in the low-34S/32S group mostly exceeds this range, giving the values typically in the range of -45(〕SY.+-.〔)10 %, which is similar to what is generally observced in the present-day oceanic sediments. The present data would provide strong evidence for the development of a largely stagnant, anoxic stratified ocean, which presumably began to form in the early Late Permian and persisted into the Early Triassic, and for the outbreak of its temporary massive mixing just at the suspected P/Tr boundary. Such an oceanic oxic-anoxic histor

在日本千叶地体的天神丸和丹波地体的Sasayama，获得了横跨二叠纪/三叠纪（P/Tr）界线的以硅质岩为主的连续泥灰岩沉积序列的全岩硫化物的系统硫同位素数据。P/Tr边界的特征是硅质页岩与碳质黑色泥岩的出现，碳质黑色泥岩在外观上类似于全球分布的白垩纪/第三纪（K/T）边界粘土岩。观察到的数据清楚地表明了显著的双峰性。相对于CDT的34 S/32 S比值在整个Hiddle二叠纪（约- 39 - 25%）。并显示出一个显着的增加开始在较低的上二叠世和持续到下三叠世（约- 20至-2%），随着一个暂时的和剧烈的负位移，下降到大致相同的同位素水平，在Hiddle二叠纪，只是在可疑的P/Tr边界（约- 41%至-23%）。有趣的是，同位素漂移的方式跨越P/Tr的边界是在鲜明的对比，最近在日本北海道的Kawaruppu在K/T的边界。高~（34）S/~（32）S组相对于同期海水硫酸盐的表观分馏程度在-25SY. ±-范围内。()10%，这在数量上相当于目前确认的细菌异化硫酸盐还原过程中动力学同位素效应的范围，并且在低-34S/32S组中，该值大多超过该范围，给出了典型地在-45（）SY ±-范围内的值。()10%，这与当今海洋沉积物中普遍观察到的情况相似。目前的数据将提供强有力的证据，一个基本上停滞，缺氧分层的海洋，这大概开始形成在晚二叠世早期，并持续到早三叠世的发展，和爆发的临时大规模混合只是在可疑的P/Tr边界。这种海洋缺氧-缺氧的历史

项目成果

Kajiwara,Y.他4名: "Development of a largely anoxic stratified ocean and its temporary massive mixing at the Permian/Triassic boundary" Palaeoceanogr.Palaeoclimatol.Palaeoecol.105(印刷中). (1994)

Kajiwara, Y. 和其他 4 人：“二叠纪/三叠纪边界处很大程度上缺氧的分层海洋的发展及其暂时的大规模混合”Palaeoceanogr.Palaeoclimatol.Palaeoecol.105（出版中）。

Shimada,T.and Kajiwara,Y.: "Sulfur isotopic variation within the Cretaceous/Tertiary boundary claystone at Kawaruppu in Hokkaido,Japan" Ann.Rep.,Inst.Geosci.,Univ.Tsukuba. 18. 98-101 (1992)

Shimada,T. 和 Kajiwara,Y.：“日本北海道 Kawaruppu 的白垩纪/第三纪边界粘土岩中的硫同位素变化”Ann.Rep.，Inst.Geosci.，Univ.Tsukuba。

Kajiwara, Y., Ishida, K., Tanikura, Y.and Ishiga, H.: "Sulfur isotope data from the Permian/Triassic boundary at Sasayama in the Tanba Terrane in central Honshu, Japna." Ann.Rep., Inst.Geosci., Univ.Tsukuba. 19. 67-71 (1993)

Kajiwara, Y.、Ishida, K.、Tanikura, Y. 和 Ishiga, H.：“来自日本本州中部丹波地体笹山二叠纪/三叠纪边界的硫同位素数据”。

Kajiwara,Y.他3名: "Sulfur isotope data from the Permian/Triassic boundary at Tenjinmaru in the Chichibu Terrane in eastern Shikoku,Japan" Ann.Rep.,Inst.Geosci.,Univ.Tsukuba. 19. 59-65 (1993)

Kajiwara, Y. 和其他 3 人：“日本四国东部秩父地体 Tenjinmaru 边界的硫同位素数据”Ann.Rep.，Inst.Geosci.，Univ.Tsukuba 19. 59-65（ 1993）

Kajiwara, Y., Yamakita, S., Ishida, K., Ishiga, H.and Imai, A.: "Development of a largely anoxic stratified ocean and its temporary massive mixing at the Permian/Triassic boundary supported by the sulfur isotopic record." Palaeoceanogr.Palaeoclimatol.Pala

Kajiwara, Y.、Yamakita, S.、Ishida, K.、Ishiga, H. 和 Imai, A.：“硫同位素记录支持了很大程度上缺氧的分层海洋的发展及其在二叠纪/三叠纪边界的临时大规模混合