There exists a large-scale transgressive onlap boundary between the Langshan Formation and its underlying strata.

证实郎山组与下伏地层之间存在一大型海侵超覆界面；

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There exists a large-scale transgressive onlap boundary between the Langshan Formation and its underlying strata.

证实郎山组与下伏地层之间存在一大型海侵超覆界面；

youdao