These provide base for the correct measurement and valuing of graptolite reflectivity.从而为笔石反射率的正确测定和取值奠定了基础.The black graptolite shale facies indicate a deep - water, half enclosed and anoxic sedimentary environment.中奥陶世...

n.笔石（古无脊椎动物，现存化石）...

graptolite的音标：graptolite的英式发音音标为：['græptəlaɪt]graptolite的美式发音音标为：['græptəlaɪt]...