Lower Cretaceous 白垩纪早期
lower cretaceous oils 后白垩纪石油
upper jurassic-lower cretaceous 上侏罗下白垩统
upper jurassic-lower cretaceous strata 上侏罗下白垩统
Lower Cretaceous Lakang Formation 下白垩统拉康组
the lower cretaceous 下白垩统
lower cretaceous aquifer 下白垩统含水层
Permo Carboniferous coal series have relative good coal gas potential, dark mudstones in lower Jurassic, lower part of Middle Jurassic and lower Cretaceous are the best source rocks.
区内石炭—二叠纪煤系具有良好的煤型气及一定的煤层气潜力，中、下侏罗统和下白垩统暗色泥岩类是最具生油潜力的烃源岩系。
Chagan depression is in the east of Yin 'gen basin, and lower cretaceous is major exploration stratum.
查干凹陷位于银根盆地东部，勘探主要目的层为下白垩统。
In this paper, the mudstone acoustic time difference method and the vitrinite reflectance method are used to calculate the Lower Cretaceous denuded thickness in the Santanghu basin.
文中利用泥岩声波时差和镜质体反射率法计算了三塘湖盆地下白垩统的剥蚀量，两种方法得出的结果吻合较好。
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