黑龙江东部盆地群白垩纪海侵存在的矿物学证据及其意义

Mineralogical evidences and significance of transgression event in the Cretaceous basins of eastern Heilongjiang Province,China

前人研究所获得的海相化石证据表明,中国黑龙江东部早白垩世早期曾发生多次规模不等的海侵,多层厚度不等的海相夹层赋存于下白垩统中。对研究区白垩纪砂岩中的海绿石、独居石、莓状黄铁矿等自生矿物的显微特征、扫描电镜背散射特征和化学特征进行分析,结果证实,这些特征均与典型海侵相的特征接近,说明不仅含海相化石的层位系海侵成因,含这些自生矿物的砂岩、粉砂岩的层位也受到海侵的影响,从而为黑龙江省东部盆地在白垩纪发生过海侵提供矿物学的依据。

The evidences of marine fossils show that multiple different scales of transgression events have occurred in the Cretaceous basins of eastern Heilongjiang Province and marine interlayers of various thicknesses existed in Lata Cretaceous strata. According to further comparative study based on microscope observation, the SEM and the spectrum characteristics of chemical composition all proved that the glauconite, authigenic monazite and framboid pyrite in Cretaceous sandstones have similar characteristics to marine facies. Thus, it proiveds mineralogical evidence to transgression event in the Cretaceous basins of eastern Heilongjiang Province, and indicate that not only those marine fossils containing stratum were influenced by transgression, but also these authigenic minerals containing stratums were influenced.