The genus and species Yuyuanozoon magnificissimi gen. et sp. nov., a new fossil vetulicolian, is reported from the Early Cambrian Chengjiang Fauna in Yunnan of China. It has a bipartite body plan and five pairs of cha...The genus and species Yuyuanozoon magnificissimi gen. et sp. nov., a new fossil vetulicolian, is reported from the Early Cambrian Chengjiang Fauna in Yunnan of China. It has a bipartite body plan and five pairs of chain-formed gill sacs, showing the general characteristics of Ventulicolia. However, the exclusive 'atrial cavity' and external gill observed indicate that the new form is different from those previously described as vetulicolians, probably representing a lineage developed within deuterostomes and more primitive than urochordates.展开更多
The ore genesis model for barite deposits in east Guizhou Province has been in dispute and the major debate focuses on whether they are product of the submarine hydrothermal sedimentation. This note presents new stron...The ore genesis model for barite deposits in east Guizhou Province has been in dispute and the major debate focuses on whether they are product of the submarine hydrothermal sedimentation. This note presents new stron- tium isotope data from 19 samples of Dahebian and Yuping barite deposits, and their 87Sr/86Sr ratios are significantly lower than that of the coeval seawater. The Sr/86Sr ratios of 87 17 samples out of 19 samples rang from 0.708310 to0.708967, indicating that theymight be related to the mantel admixture. Two isotopic ratios in this study are higher than those of coeval seawater (0.7090), collected from late-stage barite mineral vein of interpenetrative strata and a barite nodule bearing hypidiomorphic granular pyrite, which indicates that they might be related to the continental admixture. The study provides Sr isotopic evidence not only for the subma- rine hydrothermal exhalative genesis of Dahebian and Yup- ing barite deposits, but also for distinguishing the barite mineralization of late stage.展开更多
基金supported by the National Natural Science Foundation of China(Grants 40073007,40173002,40232020)the Natural Scienee Foundation of Yunnan Province(Grant 97D007Z)
文摘The genus and species Yuyuanozoon magnificissimi gen. et sp. nov., a new fossil vetulicolian, is reported from the Early Cambrian Chengjiang Fauna in Yunnan of China. It has a bipartite body plan and five pairs of chain-formed gill sacs, showing the general characteristics of Ventulicolia. However, the exclusive 'atrial cavity' and external gill observed indicate that the new form is different from those previously described as vetulicolians, probably representing a lineage developed within deuterostomes and more primitive than urochordates.
文摘The ore genesis model for barite deposits in east Guizhou Province has been in dispute and the major debate focuses on whether they are product of the submarine hydrothermal sedimentation. This note presents new stron- tium isotope data from 19 samples of Dahebian and Yuping barite deposits, and their 87Sr/86Sr ratios are significantly lower than that of the coeval seawater. The Sr/86Sr ratios of 87 17 samples out of 19 samples rang from 0.708310 to0.708967, indicating that theymight be related to the mantel admixture. Two isotopic ratios in this study are higher than those of coeval seawater (0.7090), collected from late-stage barite mineral vein of interpenetrative strata and a barite nodule bearing hypidiomorphic granular pyrite, which indicates that they might be related to the continental admixture. The study provides Sr isotopic evidence not only for the subma- rine hydrothermal exhalative genesis of Dahebian and Yup- ing barite deposits, but also for distinguishing the barite mineralization of late stage.
