The Raohe area of Heilongjiang Province,Northeast China belongs to the Nadanhada Terrane,which was in low latitudes of Panthalassa during the Triassic.The composition of the Late Triassic conodont fauna,derived from l...The Raohe area of Heilongjiang Province,Northeast China belongs to the Nadanhada Terrane,which was in low latitudes of Panthalassa during the Triassic.The composition of the Late Triassic conodont fauna,derived from limestone lenses interpreted to formed on seamounts,provides important new information on the pelagic biota in this ocean.New conodont samples collected from sections at Minzhu,Minnan and Chigangbei sections belong to three Norian conodont zones.In ascending order,they are:Mockina postera Zone,Mockina bidentata Zone and Parvigondolella andrusovi Zone.The Norian conodont fauna in the Raohe area has distinct attributes:there are a lot of cosmopolitan species(e.g.,Mockina postera,Mockina bidentata,Parvigondolella andrusovi)which enable good global correlation;endemic conodont species are also present(e.g.,Mockina sakurae,Mockina shamiseni,Norigondolella nadanhadaensis)indicating that Panthalassa Ocean conodont populations also contained unique taxa;and some conodonts belong to taxa with much shorter ranges in surrounding epeiric seas(e.g.,Carnepigondolella pseudoechinata,Neocavitella cavitata and Epigondolella vialovi).The presence of the latter“relicts”indicates that the seamounts were persistently suitable habitats for many millions of years in the Late Triassic.展开更多
基金supported by the National Natural Sciences Foundation of China(Nos.42372005,41830320,41972033)。
文摘The Raohe area of Heilongjiang Province,Northeast China belongs to the Nadanhada Terrane,which was in low latitudes of Panthalassa during the Triassic.The composition of the Late Triassic conodont fauna,derived from limestone lenses interpreted to formed on seamounts,provides important new information on the pelagic biota in this ocean.New conodont samples collected from sections at Minzhu,Minnan and Chigangbei sections belong to three Norian conodont zones.In ascending order,they are:Mockina postera Zone,Mockina bidentata Zone and Parvigondolella andrusovi Zone.The Norian conodont fauna in the Raohe area has distinct attributes:there are a lot of cosmopolitan species(e.g.,Mockina postera,Mockina bidentata,Parvigondolella andrusovi)which enable good global correlation;endemic conodont species are also present(e.g.,Mockina sakurae,Mockina shamiseni,Norigondolella nadanhadaensis)indicating that Panthalassa Ocean conodont populations also contained unique taxa;and some conodonts belong to taxa with much shorter ranges in surrounding epeiric seas(e.g.,Carnepigondolella pseudoechinata,Neocavitella cavitata and Epigondolella vialovi).The presence of the latter“relicts”indicates that the seamounts were persistently suitable habitats for many millions of years in the Late Triassic.
