浙闽地区下白垩统黑色泥岩沉积环境初探:微体古生物与有机地球化学证据

在中国东南沿海浙闽地区的中生代火山岩分布区，广泛发育有中生代沉积岩系，关于这套沉积岩是否受到海水作用影响，目前还存在争论。通过对福建下白垩统坂头组（K1b）、浙江地区为寿昌组（K1s）和馆头组（K1g）地层进行系统观察及采样，并进行详细的古生物化石观察及有机地球化学研究，发现该区沉积岩中除陆相高等植物之外，还见过渡相的线叶植物和海相红藻和褐藻化石；同时某些有机地球化学特征亦显示其具有一定的海相沉积特征，如普遍存在较高的伽马蜡烷含量，伽马蜡烷/C30藿烷比值较低（0.11～0.18，平均值0.14），以及C30重排藿烷检出。因此，从古生物学与有机地球化学特征来看，该区的确受到海侵作用影响，结合地质背景，推测海侵事件主要受古太平洋域的影响。

Preliminary Investigation on Depositional Environment of Black Mud in Lower Cretaceous,Zhejiang and Fujian Provinces:Micropaleontology and Organic Geochemical Evidences

Sedimentary rocks of lower Cretaceous widely distribute in volcanic-covered area in Zhejiang and Fujiang provinces,southeast China,and its sedimentary environment that whether it has been influenced by marine water is still controversial.Though carefully observation in outcrops,we have systematically sampled dark sedimentary rocks,including Bantou Formation(K1b) in Fujian province,Shouchang Formation(K1s) and Guantou Formation(K1g) in Zhejiang province.Under microscope,besides high plant,marine fossils such...