赣中南华纪晚世源里组的重新厘定

在赣中地区开展的1：5万区调工作中，于南华纪早世古家组之上新发现一套变沉凝灰岩、变余砂岩、千枚岩夹灰岩组合，其层位与南华纪晚世下坊组相当，但岩性组合差异很大，两者属同时异相的沉积产物。早期工作中由于认识上的原因，将这套岩性组合及其下伏古家组合砾岩石组合统称源里组。新厘定的源里组是将原定义的源里组下部含砾的岩石组合划归古家组，其上部不含砾的这套岩石组合才归属于重新厘定的源里组。鉴于新厘定的源里组分布于扬子板块与华南板块对接带的南缘，代表古家组冰碛岩之上沉积的一套斜坡相浊积岩，与下坊组盆地相复理石建造明显不同，其空间展布及其边界对确定两大板块的分界线具有重要的大地构造意义，故本文作者将该套岩性组合重新厘定为源里组，时代归属于南华纪晚世．

Revision of the Late Nanhuan Peroid Yuanli Formation in the Central Part of Jiangxi

Through 1:50000 regional geological mapping in the central part of Jiangxi , a suite of rock association including of blastotuff, blastosandstone , phyllite and limestone interlining are found in upper part of Gujia Formation in early Nanhuan Peroid . It's horizontally corresponding to Xiafang Formation in the late Nanhuan Peroid, but their lithological assemblages are very difference. They belong to the sediment of isochroneity but different facies. On the basis of new data ,this suite of gravel- bearing rock association in the lower horizons of the original Yuanli are assigned to Gujia Formation, and the suite of the non gravel- bearing rock association in the upper part of the original Yuanli formation are assigned to the revised Yuanli Formation. The revised Yuanli Formation situated in the southern margin of junction between Yangtze Plate and Huanan Plate, it represents the sediments of slope facies turbidite in the upper part of tillite of Gujia formation, and it is complete difference with Xiafang Formation which belongs to flysch Formation of basin facies. It's boundary and distribution take on important geotectonic meaning for confirming the boundary line of the two Plates. Hence, this suite of rock association is revised to Yuanli Formation, and it's era belongs to the late Nanhuan Peroid.