Devonian Trace Fossils and Paleoenvironments from Ganxi of Sichuan, Southwest China

摘要

GEOLOGICAL SETTING The Ganxi section (31°54.302′N, 104°41.643′E) is one of the most typical marine Devonian sections in South China. The Devonian strata outcrop well along the Pingtonghe River in the northwest of Chengdu, Sichuan, Southwest China, with the total thickness of 3 181.9 m for the Lower, Middle and Upper Devonian. The Devonian strata in the Ganxi section are uncon-formably overlain by the slightly metamorphic Silurian muddy siltstones, and conformably underlain by the Lower Carboniferous fossiliferous limestones. The lower and the middle upper parts of the Lower Devonian mainly consist of fine- to medium-grained sandstones, muddy siltstones and mudstones. Carbonates are dominant in the upper Lower Devonian to the Upper Devonian. Body fossils and trace fossils and other facies indicators are abundant (Figs. 1, 2).