摘要
滇东、黔西和桂北地区在早三叠世早期为一辽阔的古海盆,西靠康滇古陆,南邻马关古陆,北接上扬子海,东有桂林海峡。海水经桂林海峡进入湖广海盆而连接下扬子海。早三叠世以后,古陆不断扩展,海域逐渐缩小,至晚三叠世末全区隆起成陆地。本区下、中三叠统发育,化石丰富,各期相变明显。
The conodonts described here were collected from the 28 Triassic sections in eastern Yunnan, western Guizhou and northern Guangxi, representing different facies realms as shown in Figs.2-5.These conodonts are of different characters.Two major types of con-odont zonation, the 'platform facies type' and 'basinal facies type' are recognized.Sixteen 'basinal facies type' conodont assemblages have been herein recognized in ascending order: 1.Anchignathodus minutus Zone (= Hindeodus mi nut us Zone), 2.Anchignathodus parvus Zone (= Hindeodus parvus Zone), 3.Jsarcicella isarcica Zone, 4.Neogo-ndolclla carinata Zone, 5.Neospathodus dieneri Zone, 6.Neospathodus patystanensis Zone, 7.Neospathodus conservativus Zone, 8.Neospathodus cf.ivaagcni Zone, 9.Neospathodus homeri-Neogondolella jubata Zone, 10.Neospathodus timorensis Zone, 11.Neogondolella regale Zone, 12.Neogondolella bijurcata Zone, 13.Neogondolella constricta-N.excelsa Assemblage Zone, 14.Neogondolella mombergensis Zone, 15.Neogondolella polygnathijo-rmis-Gladigondolella Assemblage Zone, 16.Neogondolella polygnathiformis Zone0On the other hand,12 conodont assemblages of the 'platform facies type' also have been recognized in ascending order.1.AnchignatAodus minutus Zone, 2.Anchignathodus parvus Zone,3.Plat ,villosus costatus, Zone,4.Pachycladina symmetrica-P.inclinata Assemblage, 5.Pachycladina bidentata-Glad-igondolella carinata Assemblage, 6.Neospathodus triangularis Zone, 7.Neospathodus timo-reasis Zone, 8.Neospathodus germantcus Zone, 9.Neospathodus kockeli Zone, 10.Neogondolella constricts Zone, 11.Neogondolella poly gnat hijormis-Gladigondolella Assemblage Zone, 12.Neogondolella polygnathiformis Zone.Based upon several correlation criteria, the correlation between the two types of conodont zonation ha; been established as shown in Table 1.A mixed fauna of Permian-Triassic has been found from the base of the Luolou or Majiaoling Formation of this region.At the base of the Lower Triassic an important Permian conodont fauna, the Neogondolella subcarinata Fauna, became extinct, but Anchignathodus minutus, which was flourishing in the Permian still survived and extended into the Lower Triassic in association with the Triassic conodonts Anchignathodus parvus and Isarcictlla isarcica at the base of Lower Triassic.
出处
《地层学杂志》
CSCD
北大核心
1990年第1期15-35,共21页
Journal of Stratigraphy
