With the definition and adoption of the Global Stratotype Section and Point （GSSP） for base of the Visean in China, the newly synthesized zonations and correlation of some significant fossil groups： foraminifera, c...With the definition and adoption of the Global Stratotype Section and Point （GSSP） for base of the Visean in China, the newly synthesized zonations and correlation of some significant fossil groups： foraminifera, conodont, coral and brachiopoda near the Tournaisian-Visean boundary beds are reviewed, which help in the recognition of the boundary in various sedimentary facies. The occurrence of two physical events, one pre- and one post- the Tournaisian-Visean boundary is emphasized, which allows for recognition of the position close to the Tournaisian-Visean boundary in the field. The regional correlation in southern China and international correlation throughout Eurasia around the Tournaisian-Visean boundary beds with the GSSP is proposed.展开更多
A stratotype section, boundary point and conodont sign have been recommended for GSSP of the Tournaisian-Visean boundary, based on studies of sectional sedimentology, conodont facies and phylogeneses in South China. T...A stratotype section, boundary point and conodont sign have been recommended for GSSP of the Tournaisian-Visean boundary, based on studies of sectional sedimentology, conodont facies and phylogeneses in South China. Two areas representing margin and inner of the Yangtzi Plate and three sections of different facies were chosen, i.e. the Longdianshan sec-tion of the platform facies in Liuzhou of Guangxi, the Yudong section of the ramp facies in Shidian of Yunnan and the Pengchong section of the basin facies in Liuzhou of Guangxi. Stratigraphic frameworks of two areas were set up by systematical studies of carbonate facies and cycles. Conodont facies-distribution and paleoecologic conditions were researched on statistics of fossil variation and richness, and a kind of planktonic conodont, gnathodids that were widespread, is chosen to select the sign-fossil from it. Seven conodont pedigrees were supplemented or erected by studies of statistics and transitional forms. Conodont evolution in the Early Carboniferous could be divided into three stages, i.e. the Siphonodella stage, the Gnathodus typicus stage and the Gnathodus bilineatus stage. The transform-surface between the later two stages could be put as the Tournaisian-Visean boundary. Finally, this paper proposes that the Pengchong section can be the stratotype candidate of the Tournaisian-Visean boundary, the boundary point be put at the bottom of bed 58 and the stratotype sign of conodont be the first occurrence of Gnathodus praebilineatus of the Gnathodus semiglaber branch.展开更多
A new early Visean coral assemblage has been recorded from turbidite facies in the southern part of the AzrouKhenifra Basin,northwest of Khenifra,central Morocco.The newly discovered Ba Moussa West(BMW)coral fauna inc...A new early Visean coral assemblage has been recorded from turbidite facies in the southern part of the AzrouKhenifra Basin,northwest of Khenifra,central Morocco.The newly discovered Ba Moussa West(BMW)coral fauna includes Siphonophyllia khenifrense sp.nov.,Sychnoelasma urbanowitschi,Cravenia lamellata,Cravenia tela,Cravenia rhytoides,Turnacipora megastoma and Pleurosiphonella crustosa.The early Visean age of the coral assemblage is supported by foraminiferal and conodont data,with the recognition of the basal Visean MFZ9 Zone.This confirms that the first transgression in the Azrou-Khenifra Basin was during the earliest Visean.The allochthonous coral assemblage was recovered from coarse-grained proximal limestone debris flow and turbidite beds within a faultbounded unit,lying to the west of a thrust syncline containing upper Visean limestones.No evidence exists of the former early Visean shallow-water platform from which the corals were derived.All other in situ platform carbonate rocks around the southern margin of the Azrou-Khenifra Basin are probably of late Visean(Asbian–Brigantian)age.The early Visean Ba Moussa West coral fauna can be compared with that at Tafilalt in eastern Morocco,as well as in other Saharian basins of Algeria.Many of the genera and species in the Ba Moussa West assemblage are identical to those in NW Europe,with which it must have had marine connections.The new rugose species described,Siphonophyllia khenifrense,is probably endemic to North Africa.Its ecological niche in NW Europe was occupied by S.cylindrica or S.aff.garwoodi.展开更多
基金supported by the Ministry of Science and Technology (Grant No. 2006FY120300-7)the National Commission on Stratigraphy of China (No. 2006CB80640)the China Geological Survey (No. 1212010916059)
文摘With the definition and adoption of the Global Stratotype Section and Point （GSSP） for base of the Visean in China, the newly synthesized zonations and correlation of some significant fossil groups： foraminifera, conodont, coral and brachiopoda near the Tournaisian-Visean boundary beds are reviewed, which help in the recognition of the boundary in various sedimentary facies. The occurrence of two physical events, one pre- and one post- the Tournaisian-Visean boundary is emphasized, which allows for recognition of the position close to the Tournaisian-Visean boundary in the field. The regional correlation in southern China and international correlation throughout Eurasia around the Tournaisian-Visean boundary beds with the GSSP is proposed.
基金This work was supported by the National Natural Science Foundation of China(Grant No.40242001).
文摘A stratotype section, boundary point and conodont sign have been recommended for GSSP of the Tournaisian-Visean boundary, based on studies of sectional sedimentology, conodont facies and phylogeneses in South China. Two areas representing margin and inner of the Yangtzi Plate and three sections of different facies were chosen, i.e. the Longdianshan sec-tion of the platform facies in Liuzhou of Guangxi, the Yudong section of the ramp facies in Shidian of Yunnan and the Pengchong section of the basin facies in Liuzhou of Guangxi. Stratigraphic frameworks of two areas were set up by systematical studies of carbonate facies and cycles. Conodont facies-distribution and paleoecologic conditions were researched on statistics of fossil variation and richness, and a kind of planktonic conodont, gnathodids that were widespread, is chosen to select the sign-fossil from it. Seven conodont pedigrees were supplemented or erected by studies of statistics and transitional forms. Conodont evolution in the Early Carboniferous could be divided into three stages, i.e. the Siphonodella stage, the Gnathodus typicus stage and the Gnathodus bilineatus stage. The transform-surface between the later two stages could be put as the Tournaisian-Visean boundary. Finally, this paper proposes that the Pengchong section can be the stratotype candidate of the Tournaisian-Visean boundary, the boundary point be put at the bottom of bed 58 and the stratotype sign of conodont be the first occurrence of Gnathodus praebilineatus of the Gnathodus semiglaber branch.
基金funded by projects CGL2012–30922 and CGL2016–78738-P of the Spanish Government.
文摘A new early Visean coral assemblage has been recorded from turbidite facies in the southern part of the AzrouKhenifra Basin,northwest of Khenifra,central Morocco.The newly discovered Ba Moussa West(BMW)coral fauna includes Siphonophyllia khenifrense sp.nov.,Sychnoelasma urbanowitschi,Cravenia lamellata,Cravenia tela,Cravenia rhytoides,Turnacipora megastoma and Pleurosiphonella crustosa.The early Visean age of the coral assemblage is supported by foraminiferal and conodont data,with the recognition of the basal Visean MFZ9 Zone.This confirms that the first transgression in the Azrou-Khenifra Basin was during the earliest Visean.The allochthonous coral assemblage was recovered from coarse-grained proximal limestone debris flow and turbidite beds within a faultbounded unit,lying to the west of a thrust syncline containing upper Visean limestones.No evidence exists of the former early Visean shallow-water platform from which the corals were derived.All other in situ platform carbonate rocks around the southern margin of the Azrou-Khenifra Basin are probably of late Visean(Asbian–Brigantian)age.The early Visean Ba Moussa West coral fauna can be compared with that at Tafilalt in eastern Morocco,as well as in other Saharian basins of Algeria.Many of the genera and species in the Ba Moussa West assemblage are identical to those in NW Europe,with which it must have had marine connections.The new rugose species described,Siphonophyllia khenifrense,is probably endemic to North Africa.Its ecological niche in NW Europe was occupied by S.cylindrica or S.aff.garwoodi.
