The Kungurian Stage is one of the three remaining stages of the Permian that is not yet defined at the base by a Global Stratotype Section and Point (GSSP). The candidate section at the Yuryuzan'River in the Urals ...The Kungurian Stage is one of the three remaining stages of the Permian that is not yet defined at the base by a Global Stratotype Section and Point (GSSP). The candidate section at the Yuryuzan'River in the Urals yields few conodonts, and contains non-marine sediments near the boundary. The search for a suitable, continuous marine succession is a principal task for the Subcommission on Permian Stratigraphy. The Leonardian, with its type area in the southwest United States, and in objective stratigraphic succession directly beneath the basal Guadalupian Roadian Stage,has priority to serve as a subseries of the Lower Permian. However, distinct provincialism limits the correlation of Leonardian fossil zones with the fusuline-based Tethyan timescale. Conodonts can be correlated in many important regions on opposite sides of Pangea, yet contradictions arise when relating conodont zones with fusuline and ammonoid zones. The different taxonomic philosophies are highly suspected for the cause of the conflicts, but also there are different conodonts from the type Roadian in West Texas. Given that the Pamir and Darvaz in central Asia are difficult to access, further investigations should focus on South China, where abundant fusulines and ammonoids facilitate correlation throughout the Tethyan region, and where conodonts permit correlation with North America.展开更多
During the Late Paleozoic,West Junggar(Xinjiang,NW China)experienced a shift in tectonic setting from compression to extension.Ha'erjiao is an important area for investigating collisional structures,post–collisio...During the Late Paleozoic,West Junggar(Xinjiang,NW China)experienced a shift in tectonic setting from compression to extension.Ha'erjiao is an important area for investigating collisional structures,post–collisional structures,and magmatic activities.Based on the petrological and geochemical characteristics of pyroclastic and other volcanic rocks in the Permian Kalagang Formation from the borehole ZKH1205 in the Jimunai Basin,the main types of source rock for the pyroclastic rocks deposited in the basin are identified and their implications for the Early Permian tectonic setting examined.The abundance of basalt and andesite lithic fragments in the pyroclastic rocks,together with the REE characteristics and the contents of transition and high field strength elements show that the source rocks were chiefly intermediate–basic volcanic rocks.High ICV values,low CIA values,low Rb/Sr ratios,low Th/U ratios and the mineralogical features suggest weak chemical weathering of the source rocks;the geochemical patterns of the pyroclastic rocks might not only have been impacted by crustal contamination but also might be related to the nature of the magma from the source area.The geochemical properties of the pyroclastic rocks distinguish them from arc-related ones,and such samples plot in the within-plate basalt(WPB)field in some diagrams.This is consistent with the formation background of the Early Permian volcanic rocks in this region.展开更多
The paper deals with the Lower Kungurian (Philippovian Horizon; Lower Permian) biota of the Mid-dle Cis-Urals, Russia. The biota is characterized on the basis of four representative localities ( Philippovskoe B...The paper deals with the Lower Kungurian (Philippovian Horizon; Lower Permian) biota of the Mid-dle Cis-Urals, Russia. The biota is characterized on the basis of four representative localities ( Philippovskoe Bus-stop, Philippovskian Quarry, Kamai and Kiselevo-Suksun Highway) , which are situated in the stratotype area of the Kungurian stage. All the localities can be regarded as Lagerstatten, but of authentically low biodi-versity ,since they represent oligotrophic lagoons of abnormal fluctuating salinity. General reconstruction of the Philippovian near-shore shallow-water ecosystem is given. Two new species of algae Algites philippoviensis sp. nov., A. shurtanensis sp. nov., and a new species of the limulids Paleolimulus kunguricus sp. nov. are de-scribed for the first time.展开更多
基金supported by MST(2006FY120300)the Chinese Academy of Sciences (KZCX2-YW-122)the National Natural Science Foundation of China
文摘The Kungurian Stage is one of the three remaining stages of the Permian that is not yet defined at the base by a Global Stratotype Section and Point (GSSP). The candidate section at the Yuryuzan'River in the Urals yields few conodonts, and contains non-marine sediments near the boundary. The search for a suitable, continuous marine succession is a principal task for the Subcommission on Permian Stratigraphy. The Leonardian, with its type area in the southwest United States, and in objective stratigraphic succession directly beneath the basal Guadalupian Roadian Stage,has priority to serve as a subseries of the Lower Permian. However, distinct provincialism limits the correlation of Leonardian fossil zones with the fusuline-based Tethyan timescale. Conodonts can be correlated in many important regions on opposite sides of Pangea, yet contradictions arise when relating conodont zones with fusuline and ammonoid zones. The different taxonomic philosophies are highly suspected for the cause of the conflicts, but also there are different conodonts from the type Roadian in West Texas. Given that the Pamir and Darvaz in central Asia are difficult to access, further investigations should focus on South China, where abundant fusulines and ammonoids facilitate correlation throughout the Tethyan region, and where conodonts permit correlation with North America.
基金This research was funded by the National Science Foundation for Young Scientists of China(No.41602176)Key Laboratory of Tectonics and Petroleum Resources(TPR–2018–16).
文摘During the Late Paleozoic,West Junggar(Xinjiang,NW China)experienced a shift in tectonic setting from compression to extension.Ha'erjiao is an important area for investigating collisional structures,post–collisional structures,and magmatic activities.Based on the petrological and geochemical characteristics of pyroclastic and other volcanic rocks in the Permian Kalagang Formation from the borehole ZKH1205 in the Jimunai Basin,the main types of source rock for the pyroclastic rocks deposited in the basin are identified and their implications for the Early Permian tectonic setting examined.The abundance of basalt and andesite lithic fragments in the pyroclastic rocks,together with the REE characteristics and the contents of transition and high field strength elements show that the source rocks were chiefly intermediate–basic volcanic rocks.High ICV values,low CIA values,low Rb/Sr ratios,low Th/U ratios and the mineralogical features suggest weak chemical weathering of the source rocks;the geochemical patterns of the pyroclastic rocks might not only have been impacted by crustal contamination but also might be related to the nature of the magma from the source area.The geochemical properties of the pyroclastic rocks distinguish them from arc-related ones,and such samples plot in the within-plate basalt(WPB)field in some diagrams.This is consistent with the formation background of the Early Permian volcanic rocks in this region.
基金supported by the State Program for Supporting Competitive Growth of the Kazan Fe-deral University among World's Leading Scientific-Educational Centers and the Russian Foundation for Basic Research
文摘The paper deals with the Lower Kungurian (Philippovian Horizon; Lower Permian) biota of the Mid-dle Cis-Urals, Russia. The biota is characterized on the basis of four representative localities ( Philippovskoe Bus-stop, Philippovskian Quarry, Kamai and Kiselevo-Suksun Highway) , which are situated in the stratotype area of the Kungurian stage. All the localities can be regarded as Lagerstatten, but of authentically low biodi-versity ,since they represent oligotrophic lagoons of abnormal fluctuating salinity. General reconstruction of the Philippovian near-shore shallow-water ecosystem is given. Two new species of algae Algites philippoviensis sp. nov., A. shurtanensis sp. nov., and a new species of the limulids Paleolimulus kunguricus sp. nov. are de-scribed for the first time.