内蒙古东乌旗地区中下泥盆统泥鳅河组沉积相研究

发育于内蒙古东乌旗地区的泥鳅河组,属于早中泥盆世沉积,厚度约1000m,主要发育泥岩、粉砂岩和灰岩沉积,粉砂岩中常常发育大量腕足类和珊瑚生物化石。首次在本区发现风暴沉积和Beaconites遗迹化石:风暴沉积由下至上包括粒序层理段、平行层理段、丘状交错层理段和浪成波纹层理段4个层段;Beaconites遗迹化石具管壁和内部水平“V”字型的回填纹构造。通过对岩相、生物化石、风暴沉积和Beaconites遗迹化石的研究显示,东乌旗地区泥鳅河组为浅海相沉积。

Sedimentary facies of the Middle-Lower Devonian Niqiuhe Formation in East Ujimqin Qi of Inner Mongolia

The Middle-Lower Devonian Niqiuhe Formation,with about 1000m thick,developed at the East Ujimqin Qi of Inner Mongolia. It mainly consists of mudstone,siltstone and limestone. A great deal of brachiopoda and coral fossils are often found in the siltstone. Storm deposit and the trace fossil of Beaconites were found for the first time. The storm deposits consist from the bottom to the top of four segments,namely graded bedding,parallel bedding,hummocky cross-bedding and wavy bedding. Beaconites is characterized by pipe wall and horizontal “V”back-packing structure. The research of petrofacies,fossils,storm deposits and Beaconites shows that the Niqiuhe Formation in East Ujimqin Qi area belongs to shallow sea facies.