The discovery of the Late Devonian fossils from the Hebukehe Formation and its stratal position in Kelasaileke Mountain, western Junggar, Xinjiang

The Hebukehe Formation is widely distributed in western Junggar. It is the synonym of the Hongguleleng Formation. This paper presents abundant fossils from the clastic strata which were previously assigned to the Lower Carboniferous Hebukehe Formation in Kelasaileke Mountain, western Junggar. These fossils include trilobites Phacops sp., ammonoids Manticoceras sp., brachiopods Tylothyris sp., Aulacella sp., "Mucrospirifer" sp. and Cyrtospirifer sp., plants Leptophloeum rhombicum, Syringodendron sp. and Knorria sp.. The age of these fossils is attributed to the Late Devonian. According to the lithologic association, the fossiliferous strata are redefined as the Upper Devonian Tielieketi Formation, rather than the Hongguleleng Formation. Regional geological survey reveals that the Upper Devonian of Mayili Mountain stratomicroregion is only composed of the Tielieketi Formation, without the Hongguleleng Formation. The latter is only distributed in the Shaerbuerti Mountain stratomicroregion. The boundary of the two stratomicroregions is the deep fault located in northern Mengbulake to south slope of Xiemisitai Mountain. These two stratomicroregions experienced obvious sedimentary differentiation during the Late Devonian, and gradually evolved into the evolutional stage of uniform basin environment until the early Early Carboniferous, announcing a gradual disappearance of stratigraphic regionalization of the stratomicroregions.