皖东张八岭、珠龙地区西冷岩组微古植物群初步研究

PRELIMINARY RESEARCH ON MICROFLORA FROM XILENG FORMATION IN THE ZHANGBALING AND ZHULONG REGIONS OF EASTERN ANHUI

皖东张八岭、珠龙地区西冷岩组为一套浅海相变质火山－沉积岩系，岩性以细碧－石英角斑岩为特征，出露面积约占总面积的80％，视厚度为4616.51m。笔者等在1：5万区域地质填图中对这套变质岩系进行了生物地层工作．并采集了大量的微占植物样品，从中获得了丰富的微古植物化石。按化石组合特征将其分为两个组合：第一组合主要产于拂晓园艺场－朱郢剖面冷岩组下部层位，包括有33个属44个种，其中1个新属，2个新种，19个未定种，3个相似种；第二组合产于西冷岩织上部层位的罗士城、邱庄、西徐等地，包括30个属．34个种．其小1个新种、18个未定种、13个相似种的化石。西冷岩组微古植物群而貌与我国青白口系的微古植物面貌比较相似．与前苏联上里菲（850－1050Ma）、澳大利亚小部苦泉组微古植物面貌相似。因此，将西冷岩组的时代归为广义的青白口纪较为合适。

The Xileng Formation consists of a suite of neritic rock series of metamurphic volcanicsedimentary in the Zhangbaling and Zhulong regions, eastern Anhui, of which lithology ischaracterized by spilite-quartz keratophyre. Owing to lack of biological fossils, the subdivisiunand correlation as well as the ownership of the age of the metamorphic rock series in this regionhave been in confusiun for a long time.In recent years, we have studied the biustratigraphy in Zhangbaling and Zhulong regions,eastern Anhui, and found more abundant microflora fossils within section and some routepoints. The microflora fossils of the Xileng Formatiom may be divided into two assemblages.The fossils of the first assemblage found in the section of the Fuxiao Horticultural Gardento Zhuying contain 33 genera, 44 species,of which 1 genus and 2 species are ncwly discovered,19 unidentified species, 3 conformis. The fossils of the second assemblage found in some routepoints such as Luoshicheng, Yingzhong, Wawuyu and Xixu, contain 30 genera, 34 species,of which 1 species is new, 18 unidentified, 13 conformis. The sedimentary age revealed by thesecond assemblage seems younger than that of the first assemblage.According to microflora assembtage, the authors ascertain the age of the Xileng Formation in this region belongs to the Qingbaikuu system in a broad sense.