论凯里组

ON THE KAILI FORMATION

记述了黔东南凯里组三叶虫的地层分布 ,讨论了三叶虫的分带 ,根据三叶虫地层分布情况 ,将凯里组与国内外同期地层进行了对比 ,指出了凯里生物群与布吉斯页岩生物群 ,斯潘塞页岩生物群出现的顺序 ,对于深入研究凯里生物群与其它生物群的演化具有重要意义。

The Kaili Formation bearing the Kaili fauna crops out in a continuous NE SW outcrop belt from Danzhai County via Taijiang, Yuping to Tongren in SE Guizhou, S China for about 370km (Zhao et al., 1993, fig.1). This Formation underlying uppermost part dolomite of Wuxun Formation and overlying lowermost part black carbonaceous thin bedded limestone intercalated with carbonaceous shale of the Jialao Formation includes lithologically three parts: the lower part about 25—70m thick is composed of grey, dark grey calcareous sandy mudstone intercalated with dark grey calcareous shale and thin bedded limestone; the middle part about 80—190m thick is made up of greenish grey, grey to yellowish green calcareous silty mudstone intercalated with grey shale and the upper part about 30—45m in thickness consists of light grey thin bedded argillaceous limestone and bioclastic limestone. The Kaili Formation can be divided four trilobite Zones in ascending order: 1. Bathynotus Nangaops Zone, 2. Wuxunaspis Zone, 3. Danzhaiaspis Xingrenaspis Zone, 4. Olenoides jialaoensis Zone. Bathynotus Nangaops Zone is marked by the first appearance of Balangcunaspis Yuan et Zhao, 1997 as its lower limmit and by the extinction of Nangaops Yuan et Sun, 1980 as its upper limit. This zone is characterized by the presence of Redlichia, Bathynotus. The main components of the zone contain the following genera: Chittidilla (Diandongaspidella), Eokaotaia, Danzhaina, Nangaoia (Gedongaspis), Kunmingaspis, Olenoides, Ovatoryctocara, Oryctocephalops, Protoryctocephalus, Oryctocephalites, Microryctocara, Burlingia, Parashuiyuella, Probowmania, Pro.(Mufushania), Qiannanagraulos, Sanwania, Yuehsienszella, Redlichia, Bathynotus. Wuxunaspis Zone is defined by the first appearance of Pagetia gaotanensis Zhang, S.G., 1980 as its lower limit and by the disappearance of Wuxunspis Yuan, 1980 as its upper limit. This zone has the following features:1. The typical Lower Cambrian trilobites Redlichia, Bathynotus disappear, 2.the main elements of this zone contain not only Kunmingaspis, Danzhaina, Olenoides, Sanwania, Microryctocara, Probowmania (Mufushania), Nangaoia (Gedongaspis) of Bathynotus Nangaops Zone, but Pagetia, Xingrenaspis of Danzhaiaspis Xingrenaspis Zone. Danzhaiaspis Xingrenaspis Zoneis marked by the first apperanace of Oryctocephalus indicus (Reed, 1910) as its lower limit and by the disappearnace of Kaotaia Lu, 1962 as its upper limit. This zone exhibits not only a relativeyly higher diversity of trilobite genera, but soft body bearing Kaili biota. About twenty trilobite genera (subgenera) have been found, e.g. Xingrenaspis, Kaotaia, Jiume nia, Kailiella, Danzhaiaspis, Meitania, Kuetsingocephalus, Oryctocephalus, Oryctocephalites, Oryctocephaloides, Oryctocephalina, Metabalangia, Microryctocara, Burlingia, Paramgaspis, Nangaoia, Pianaspis, Temnoura, Probowmania (Gunnia), Chengshanaspis, Peronopsis. Olenoides jialaoensis Zone is marked by the presence of Olenoides jialaoensis (Lu et Chien, 1978). The elements of this zone consist of those genera extending from Danzhaiaspis Xingrenaspis Zone, e.g. Peronopsis, Oryctocephalus, Oryctocephalites, Olenoides, Pagetia. The stratigraphical distribution of trilobite genera (subgenera) from the Kaili Formation is given on the table Ⅰ. The tentatively correlation of Kaili Formation with its synchronous strata in China is shown in table Ⅱ. and the tentatively correlation of the Kaili Formation with its synchronous strata in Laurentia and Siberian platform is given on table Ⅲ.