| 云南晋宁梅树村阶及梅树村动物群 |
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| 引用本文：蒋志文.1980.云南晋宁梅树村阶及梅树村动物群[J].地球学报,2(1):75-92. |
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| 中文摘要:<正> 一、前言 寒武系—前寒武系界限问题,历经了长期的争论和变动。由于各国界限工作者的努力,已有趋向一致的可能,已经达到可以选择一个建立这种界限层型点的程度。 云南省晋宁县梅树村剖面和王家湾剖面地层连续,代表单一的海相,含有丰富的生物化石,所含早寒武世最早期小壳动物群可以划分3个组合6个亚组合。这些组合由下至上持续更替的特征清晰,反映了动物群由低级—高级、由简单—复杂的演化序列,并且可以进行大范围的对比。1978年,国际地科联前寒武系—寒武系界限工作组决定将该两剖面选作界限层型参考工作点和参考段。 |
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| THE MEISHUCUN STAGE AND FAUNA OF THE JINNING COUNTY,YUNNAN |
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| Abstract:Both the Meishucun and Wangjiawan section in Jinning county, Yunnanprovince, represent a stratigraphically continuous section of marine depositscontaining abundant small shelly fossils. These section are readily accessibleand ideal for studying the Precambrian-cambrian boundary as comparedwith those both at home and abroad. The Meishucun stage is the lowest stageof the early Cambrian in China. It represents a smally shelly fossil assemblage-bearing stratigraphic unit below the first appearance of the oldest trilobites and archaeostracods. The Meishucun section is the stratotype for the Meishucon stage. Small shelly fossils in the Meishucun section have been studied since 1941. According to the systimatic study of data obtained from continuous channel sampling of the section, the small shelly fossils can be divided into three assemblages and six sub-assemblages. The characteristics of the changes of these fossil assemblages from bottom to top clearly reflects the evolution of small shelly faunas from lower grade to higher grade and from simple to complicated form. The forst 3 sub-asssemblages of the first assemblage are Pre-Tommotain. The Meishucun stage and fauna are widely correlatable with those both at home and abroad. This paper deals with(1)the characteristics of the Meishucun faunal assenblages and their correlation with those found in other parts of the country and in the world; (2)It is suggested that the boundary between the Precambrain and Cambrain in China Should be placed at the bottom of the Meishucun stage, and (3)descriptions and illustrations of new genera and species. |
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