The Trilobite Biostratigraphy Of The Cambrian Series 2,Stage 4 In Jianhe County,Guizhou Province

The Cambrian strata is well exposed in eastern Guizhou,which is beneficial to further stratigraphic research.Abundant of Orythctocephalus and Redlichia was collected in the Balang Formation,“Tsinghsutung Formation” and the lower part of Kaili Formation,which provide abundant materials for the divide biostratigraphic work of the Cambrian Stage 4.Statistically,there were 8 genera and 10 species of trilobites in Balang Formation,they are Arthricocephalus chauveaui,Arthricocephalus xinzhaiheensis,Balangia balangensis,Changaspis elongata,Duyunaspis duyunensis,Oryctocarella duyunensis,Oryctocarella balangensis,Probowmania balangensis,Redlichia(Pteroredlichia)chinensis,Longaspis paiwuensis.15 genera and 19 species triliobites were collected the Tsinghsutung Formation,they are Arthricocephalus chauveaui,Burlingia balangensis,Balangcunaspis transversus,Dinesus panxinensis,Duyunaspis jianheensis,Eoptychoparia cf.Yunnanensis,Danzhaina lilia,Eoptychoparia gaodongensis,Mufushania cf.Nankingensis,Nangaops danzhaiensis,Olenoides constrictus,Olenoides cf.Hubenensis,Oryctocarella duyunensis,Protoryctocephalus arcticus,Panxinella angustilimbata,Redlichia(Redlichia)guizhouensis,Redlichia(Redlichia)nobilis,Redlichia(Pteroredlichia)chinensis,Yuehsienszella magna.There were 27 genera and 27 species of trilobites in Kaili Formation,they are Bathynotus kueichouensis?Balangcunaspis transversus?Burlingia ovata?Chittidilla brevis?Danzhaina conica?Eodouposiella taijiangensis?Eokaotaia gedongensis?Euarthricocephalus taijiangensis?Kermanella angustilimabata?Kunmingaspis yunnanensis?Mufushania nankingensis?Nangops brevis?Nangoia megaceps?Oryctocephalops guizhouensis?Ovatoryctocara sinensis?Olenoides hubeiensis?Oryctocephalites longus?Protoryctocephalus balangensis?Probowmania balangensis?Parashuiyuella subcylindrica?Pagetia significans?Qiannanagraulos costatus?Redlichia(Redlichia)takooensis longispina?Sinoschistometopuus latilimbata?Schmalensia rara?Sanwania prima?Xingrenaspis xingrenensis?According to the stratigraphic range and geographical distribution of trilobites,the biostratigraphy of the Cambrian stage 4 in Jianhe county was divided from the bottom to up as follow: Oryctocarella duyunensis-Arthricocephalus chauveaui Interval Zone;Arthricocephalus chauveaui Zone;Protoryctocephalus arcticus Zone;Bathynotus kueichouensis-Ovatoryctocare sinensis Assemblage Zone.Based on the collection of trilobites biostratigraphy range and geographical distribution,the trilobite biostratigraphy of Cambrian stage 4 in Jianhe County was divided as follows(from bottom to top): Oryctocarella duyunensis-Arthricocephalus chauveaui Interval Zone;Arthricocephalus chauveaui Range Zone;Protoryctocephalus arcticus Range Zone;Bathynotus kueichouensisOvatoryctocare sinensis Assemblage Zone.The Oryctocarella duyunensis-Arthricocephalus chauveaui Zone is equivalent with Palaeolenus Zone in eastern Yunnan and the top of Palaeolenus Zone in North China;the bottom of Arthricocephalus chauveaui Zone is lower than HoffetellaRedlichia(Pteroredlichia)chinensis in eastern Yunnan and higher than that Redlichia(Pteroredlichia)chinensis Zone in North China.The top boundary of Arthricocephalus chauveaui Zone is lower than Redlichia(Pteroredlichia)chinensis Zone in North China;the bottom boundary of Protoryctocephalus arcticus Zone is lower but top boundary is higher than Redlichia(Redlichia)guizhouensis Zone in eastern Yunnan,which same happens with Redlichia(Redlichia)nobilis Zone in North China to Protoryctocephalus arcticus Zone in Jianhe County.