新疆北部密西西比亚纪早期无鳞板的单体珊瑚

EARLY MISSISSIPPIAN NON-DISSEPIMENTED SOLITARY RUGOSE CORALS FROM NORTHERN XINJIANG

新疆北部准噶尔盆地东缘巴里坤、西缘托里与西北缘和布克赛尔等地的密西西比亚纪早期地层为一套较深水相的黑色页岩与生物屑泥晶灰岩,产浮游生活的菊石、牙形类和营底栖固着生活的腕足类、腹足类、双壳类、苔藓虫、无鳞板的单体珊瑚以及孢子等化石。根据鉴定,该地层时代应属于密西西比亚纪(或称早石炭世)早期,相当于国际地层表中的杜内阶(Tournaisian)。产出珊瑚分别为:Amplexus gennarenensis sp.nov.,Cyathaxonia stereoseptata,Hapsiphyllumcrissum,Meniscophyllumirregulare,Rotiphyllumxinjiangensesp.nov.,Zaphrentites parallelus(Carruthers),Neozaphrentis sp.,fam.gen.et sp.indet.。

The Early Mississippian strata in Barkol that is located in the east margins of the Junggar Basin,and Toli and Hoboksar counties that are located in the west margins of the Basin,north Xinjiang are characterized by the occurrences of relatively deep-water black shale and bioclastic micrite limestone,yielding abundant pelagic ammonoids,conodonts and benthic brachiopods,bryozoans,gastropods,bivalves,tabulate corals,non-dissepimented solitary rugose corals,and spores,etc.According to the assemblages of ammonoids and conodonts,the strata is undoubtedly of Early Mississippian in age,within the Tournaisian Stage of the international chronostratigraphic chart.The rugose corals from four different Early Mississippian outcrops of north Xinjiang are investigated in this study,and they belong to eight species of eight different genera,including two new species and an undetermined genus and species.