There exists a large-scale transgressive onlap boundary between the Langshan Formation and its underlyingstrata.
证实郎山组与下伏地层之间存在一大型海侵超覆界面；
2
It's very significant to use the wiggled character of seismic reflector to distinguish the gas hydrates and underlying free gases in the strata.
地震反射波形特征对判断地层中是否存在天然气水合物及其下伏游离气层具有重要指示意义。
3
We have mentioned that though Luzon appears to be on the Philippine Plate, this is a land mass attached to the Philippines on the Sunda Plate because underlying rock strata hold it to the Sunda Plate.