graptolite例句

These provide base for the correct measurement and valuing of graptolite reflectivity.
從而為筆石反射率的正確測定和取值奠定了基礎(chǔ).

The black graptolite shale facies indicate a deep - water, half enclosed and anoxic sedimentary environment.
中奧陶世黑色的筆石頁巖為典型的半封閉缺氧的深水沉積環(huán)境,反映了海水逐步加深,水體也變得相對寧靜.

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