Middle Paleozoic Flysch Trace Fossils from Western Junggar and Their Palaeoenvironmental Significance
Fan Ruoying
Zhao Long
Zong Ruiwen
Gong Yiming
Abstract：The flysch trace fossils of western Junggar,Xinjiang,NW Chinaare mainly distributed in the Upper Devonian-Lower Carboniferous Ta'erbahatai Formation and Baogutu,Tailegula and Hala'alate formations of the Carboniferous.Characteristic trace fossils include Phycosiphon,Nereites,Megagrapton,Glockerichnus,Cochlichnus,Lophoctenium,Gordia,Chondrites, Zoophycos,Scolicia,Thalassinoides,forming two characteristic trace fossil assemblages of the Nereites ichnofacies:the Phycosiphon-Nereites and Megagrapton-Glockerichnus-Cochlichnus ichnoassemblages.The Baogutu and Tailegula formations represent the medial-distal submarine fan fringe-basin plain environments,while the Hala'alate and Ta'erbahatai formations are chiefly medial-distal submarine fan lobe deposits.The distribution of flysch trace fossils in western Junggar is closely linked to the thickness of the Bouma sequences.In millimetre to centimetre Bouma sequences,there are only scarce and blur traces of Phycosiphon or Nereites,while in centimetre to decimetre Bouma sequences,Phycosiphon and Nereites of various diametres and transitional morphologies occur,which might be produced by conspecific trace makers in an ontogenetic series.The thick-ness of a single Bouma sequence in submarine fan related environments determines if there is enough time for a mature benthic fauna to develop (with a series of young and old individuals).
Keywords：trace fossilflysch faciesdepositional environmentDevonianCarboniferouswestern Junggarpalaeoenvironment
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：15( 573-587 )