陕西靖边龙洲丹霞白垩纪恐龙足迹沉积环境

2019年在陕西靖边龙洲下白垩统洛河组紫红色砒砂岩中发现多处恐龙足迹，实属罕见。含恐龙足迹地层岩石组合为一套典型沙漠相"红色砒砂岩"系，岩石组合以紫红色-暗紫红色薄层中-粗粒长石石英砂岩、石英砂岩夹灰黄色-浅紫红色块状粉砂质泥岩、泥质粉砂岩为主。发现识别出恐龙足迹行迹9处。根据足迹形态对比，推断其类型为兽脚类恐龙足迹。根据足迹产地地层剖面的研究，推断恐龙足迹分布在沙丘湖岸附近。本次发现的恐龙足迹与2017年在陕西神木中鸡发现的恐龙足迹差异明显，为陕北鄂尔多斯盆地恐龙研究提供了珍贵的研究资料。由于靖边龙洲丹霞地貌恐龙足迹产地的地层研究程度较低，因此，对恐龙足迹的研究在地层年代确定，特别是恢复岩相古环境具有重大意义。

The sedimentary environment of Early Cretaceous dinosaur tracks in Longzhou Danxia Landform of Jingbian County,Shaanxi Province

During the extensive survey on Longzhou Danxia Landform in Jingbian County of Northern Shaanxi in July 2019, Shaanxi Institute of Geological Survey found several dinosaur track sites in the purple sandstone of Early Cretaceous Luohe Formation.The dinosaur track-bearing formation belongs to a typical red arsenic sandstone of desert facies, which is mainly composed of purplish red to dark purplish red medium to coarse grained feldspathic quartz sandstone, and quartz sandstone intercalated with grayish yellow-pale purple red massive silty mudstone and argillaceous stone, constituting the typical Danxia Landform scene.Altogether 9 dinosaur trackway sites were identified.Based on the comparison of morphological features and the field survey, it can be inferred that the dinosaur trackmakers were theropod.Based on the research on the sequence of around this area, it can be inferred that these dinosaur tracks were preserved near the shoreside of a desert lake.The dinosaur tracks found in Jingbian are distinctly different from those found in Zhongji Town, Shenmu City in 2017 and can provide rare research materials for the dinosaur research in the Ordos Basin.Moreover, the dinosaur track-bearing formation is less well studied, thus the study of the dinosaur tracks will contribute greatly to ascertaining the stratigraphic age and reconstructing the paleoenvironment.