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COVER Two important geological issues have a long history of debate in the Xingmeng area.The first concerns the final closure of the Paleo-Asian Ocean, and the other concerns the folding and uplift age of the Xingmeng Trough. Disagreements arise because of issues involving the tectonic-paleogeographical environment of the Upper Permian deposits of the Linxi Formation. The Linxi Formation (Upper Permian) is generally considered to be either (a) an exclusively continental deposit or (b) separated into marine-terrigenous facies deposited during the Lower to Middle Linxi Period and continental facies deposited in the Upper Linxi Period. In their paper, Yongsheng Zhang et al. investigate the upper part of the Linxi Formation in Lopingian, within the Guandi-Zhaijiagou section of Linxi County in eastern Inner Mongolia. The limestone layers (Lin 4 and Lin 5 members) include large amounts of marine fossils (e.g., bryozoans). The fossils indicate that the Xingmeng area was still a marine or mainly marine environment at the end of the Late Permian. The cover shows examples of field outcrops of the Lin 4 and Lin 5 members with some of the marine fossils (see the article by Yongsheng Zhang et al. on page 62).
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