In the eastern Yangtze Platform of South China Block, Tremadocian (Early Ordovician) stromatolites in southern Anhui Province occur along a palaeoenvironmental transect from the shallowest intra-platform setting through to deeper platform margin. The intra-platform and platform margin belts of Tremadocian rocks in the eastern platform are carbonate-dominated marine environments favourable for calcimicrobes. However, stromatolites are absent in siliciclastic-dominated slope facies. Shallower carbonate facies are represented by the upper member of the Lunshan Formation, composed of a hundred metres thickness of stromatolite-bearing carbonates. Such stromatolites at the Beigong section of Jinxian county are characterized by stratiform and dome-shaped laminations. Girvanella filaments are ubiquitous in thin sections. Crinoids grew on the surfaces of the microbialites. In contrast, towards the deeper carbonate platform margin, stromatolites in massive-bedded limestones of the upper member of Lunshan Formation of the Ma’anshan section at Shitai occur as dense columns of bindstones; macrofossils and bioclasts are rare in those stromatolites, indicating a lower energy and deeper marine setting. Water depth at the platform margin of the Ma’anshan section is interpreted as being above the base of the euphotic zone favorable for photosynthesis in the calcimicrobial community; however, benthic fauna notably declined. In contrast to shallower settings, in clastic-dominated locations interpreted as deposited in deeper water, stromatolites are absent, represented by the middle member of Dawuqian Formation at the Ziliqian section. This work, therefore, supports that Early Ordovician reef systems were still microbial-dominated, representing the last golden age of stromatolites.

中文翻译：

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华南地块扬子地台东部微生物礁：奥陶系叠层石的最后黄金时代

在华南地块东部扬子地台，皖南三叠纪叠层石分布于从最浅的台内环境到更深的台缘的古环境断面。东台地特雷马多阶岩石的台内和台缘带是有利于钙微生物生长的以碳酸盐为主的海洋环境。然而，在硅质碎屑为主的斜坡相中不存在叠层石。较浅的碳酸盐岩相以伦山组上段为代表，由百米厚的含叠层石的碳酸盐岩组成。进贤县北宫段叠层石以层状和圆顶状层理为特征。Girvanella 细丝在薄片中无处不在。海百合在微生物岩的表面生长。相反，在更深的碳酸盐台地边缘，石台马鞍山段轮山组上段块状层状灰岩中的叠层石以致密的粘结岩柱出现；大型化石和生物碎屑在这些叠层石中很少见，表明能量较低且海洋环境较深。马鞍山段台缘水深解释为高于有利于钙微生物群落光合作用的透光带底部；然而，底栖动物群显着减少。与较浅的环境相反，在被解释为沉积在较深水中的碎屑岩为主的位置，叠层石不存在，以自力前剖面的大屋前组中段为代表。因此，这项工作，