LATE PALAEOZOIC SEDIMENTARY FACIES AND PALAEOGEOGRAPHY AND THEIR TECTONIC CONTROLS IN JIANGSHAN, ZHEJIANG

In the light of petrographic, palaeoecological and geochemical characteristics and sedimentary sequences, in combination with regional geological data, the present paper deals with the evolution and tectonic implications of the Carboniferous and Permian sedimentary facies and environments in the Jiangshan region, Zhejiang.
The Yejiatang Formation is interpreted as the rapidly accumulated products in braided rivers, and regionally,as a part of the Datangian (Early Carboniferous)alluvial facies belts on the western margin of the Cathaysia. The Outangdi Formation has the features of intercalated marine and terrestrial deposits with progradational sequences. The Shitoushan Limestones are assigned to the stable deposits on shallow-marine carbonate platforms. The Dingjiashan Formation is thought to be the turbid-water-disturbed and superimposed products during the western Zhejiang platform development.
During the Weiningian(Late Carboniferous)and Maokouian (Early Permian),the differential uplifts once occurred on the Cathaysia. The Weiningian uplifts were responsible for the formation of the progradarional sequences in the Outangdi Formation,whereas the Maokouian uplifts delivered to the turbid water with mud and sand,which permitted the development of the carbonate platforms in the Zhejiang-Anhui marine basin to be disturbed. It follows that the Variscan tectonic development is characterized by the intermittently active ancient land and steady transgressions in the study area.