This paper investigates the high-solution of Mo isotopes and uses trace-element analyses for fresh and representative black shales and siliceous shales collected from the transition between the Late Ordovician and the...This paper investigates the high-solution of Mo isotopes and uses trace-element analyses for fresh and representative black shales and siliceous shales collected from the transition between the Late Ordovician and the Early Silurian at the Wangjiawan section in Yichang and the Late Permian Dalong Formation in the Shangsi Section of Sichuan. The applicability of different geochemical parameters used as paleo-oxygenation indices are also compared. The preliminary results show that V/(V+Ni), U auth (auth U), V/Cr, Ce anom and U/Th have a scattered variation range, but most samples plot within the suboxic-anoxic fields. The suboxic-anoxic environment was dominant during the deposition and formation of the two anoxic facies. These redox indicators show little correspondence to the δ 98 Mo values. The U/Mo ratio can be used as a potential proxy for the paleo-redox conditions due to the possibility that Mo is enriched relative to U at different redox gradients during early diagenesis. This evidence is more significant for the euxinicity condition and corresponds to positive δ 98 Mo (>1.5‰) values with low U/Mo ratios. This evidence is likely related to the depositional conditions near the boundary between anoxic and euxinic environments, which are characterised by low bioturbation or water circulation. Other samples reveal a wide scatter of U/Mo ratios and δ 98 Mo <1.5‰. These results are likely due to punctuated improvements in oxygenation with intense bioturbation or water circulation, which led to the redistribution of trace element.展开更多
“这里是如此的安静和美好，在我工作的地方是那么的混乱和吵闹”。赛事总监吕华勇一落座就和记者开起了玩笑。“热闹”确实是今年上海劳力士大师赛的关键词，因为费德勒、穆雷和德约科维奇的到来，今年上海劳力士大师赛期间的观赛人数...“这里是如此的安静和美好，在我工作的地方是那么的混乱和吵闹”。赛事总监吕华勇一落座就和记者开起了玩笑。“热闹”确实是今年上海劳力士大师赛的关键词，因为费德勒、穆雷和德约科维奇的到来，今年上海劳力士大师赛期间的观赛人数突破性的达到了14．8万人，比去年增长了20％还要多。“Simply the best”是上海今年打出的标语，而在忙碌的间隙，赛事总监吕华勇和杨亦斌也抽空接受了我们的采访，娓娓道来了他们是如何精益求精接近完美的。展开更多
基金supported by National Natural Science Foundation of China (Grant Nos. 40673020, 40839903, 40821061)Ministry of Education of China (Grant Nos. IRT0441 and B07039)+2 种基金China Petroleum & Chemical Corporation Project (Grant No. G0800-06-ZS-319)MOST Special Fund from the State Key Laboratory of Geological ProcessesMineral Resources and the Fundamental Research Funds for the Central Universities
文摘This paper investigates the high-solution of Mo isotopes and uses trace-element analyses for fresh and representative black shales and siliceous shales collected from the transition between the Late Ordovician and the Early Silurian at the Wangjiawan section in Yichang and the Late Permian Dalong Formation in the Shangsi Section of Sichuan. The applicability of different geochemical parameters used as paleo-oxygenation indices are also compared. The preliminary results show that V/(V+Ni), U auth (auth U), V/Cr, Ce anom and U/Th have a scattered variation range, but most samples plot within the suboxic-anoxic fields. The suboxic-anoxic environment was dominant during the deposition and formation of the two anoxic facies. These redox indicators show little correspondence to the δ 98 Mo values. The U/Mo ratio can be used as a potential proxy for the paleo-redox conditions due to the possibility that Mo is enriched relative to U at different redox gradients during early diagenesis. This evidence is more significant for the euxinicity condition and corresponds to positive δ 98 Mo (>1.5‰) values with low U/Mo ratios. This evidence is likely related to the depositional conditions near the boundary between anoxic and euxinic environments, which are characterised by low bioturbation or water circulation. Other samples reveal a wide scatter of U/Mo ratios and δ 98 Mo <1.5‰. These results are likely due to punctuated improvements in oxygenation with intense bioturbation or water circulation, which led to the redistribution of trace element.
文摘“这里是如此的安静和美好，在我工作的地方是那么的混乱和吵闹”。赛事总监吕华勇一落座就和记者开起了玩笑。“热闹”确实是今年上海劳力士大师赛的关键词，因为费德勒、穆雷和德约科维奇的到来，今年上海劳力士大师赛期间的观赛人数突破性的达到了14．8万人，比去年增长了20％还要多。“Simply the best”是上海今年打出的标语，而在忙碌的间隙，赛事总监吕华勇和杨亦斌也抽空接受了我们的采访，娓娓道来了他们是如何精益求精接近完美的。
