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西秦岭北缘潭县地区分布的中—新生代红层地层格架和时代一直存在争议。该地区红层地层格架的正确厘定对于重建西秦岭北缘中—新生代构造地貌演化过程和认识印度-欧亚板块汇聚碰撞过程在青藏高原东北缘的远程地质响应具有重要的科学意义。通过对红层地层与下伏老地层以及不同红层地层之间的角度不整合、红层沉积序列及岩石学特征和红层地层与西秦岭北缘断层之间关系的研究,结合孢粉分析资料,重新厘定了西秦岭北缘漳县地区的红层沉积地层地质格架。研究表明,西秦岭漳县地区分布的中—新生代红层地层自下而上可分为三套地层系统,即①下白垩统紫红色砂岩、砾岩。②中新统红色砾岩、砂岩、黏土岩和深紫色-灰色泥岩、灰色泥灰岩、蒸发岩系。③上新统河流相砾岩层(韩家沟砾岩)和F1断层以北的红色洪积砾岩层。三套红层地层之间都为角度不整合面分割,相对地质关系清晰,沉积岩石特征差异明显,尽管由于断层的破坏,但没有影响到整体地层格架。三套红层地层系统反映了西秦岭北缘中—新生代不同阶段的沉积构造环境和古地貌演化过程,为研究西秦岭中—新生代陆内构造过程和青藏高原隆升、构造变形向东北缘的扩展远程效应等科学问题提供了基本的地质约束。
The Mesozoic-Cenozoic red strata stratigraphic framework and the age have been in dispute in the distribution of the Tamian County in the northern margin of the Western Qinling Mountains. The correct determination of the red beds stratigraphic framework in this area is of important scientific significance for the reconstruction of the Meso-Cenozoic tectonic landscape evolution in the northern margin of the West Qinling and for the understanding of the remote geologic response of the Indian-Eurasian plate convergence collision in the northeastern margin of the Qinghai-Tibet Plateau. Based on the study of the relationship between the red layer stratum, the underlying stratum and the red stratum, the red stratum sedimentary sequence and petrological characteristics and the relationship between the red stratum and the fault of the north margin of the western Qinling Mountains, Data, re-determine the red sandstone strata geological framework of the Zhangxian area in the northern margin of West Qinling. The research shows that the Mesozoic-Cenozoic red beds distributed in Zhang County of West Qinling can be divided into three sets of stratigraphic systems from bottom to top, that is, ① Lower Cretaceous purplish red sandstone and conglomerate. ② Miocene red conglomerate, sandstone, clay rock and deep purple - gray mudstone, gray marl, evaporite series. ③ Upper Pleistocene fluvial conglomerate (Hanjiagou conglomerate) and red flood conglomerate to the north of F1 fault. The three sets of red beds strata are divided by angle unconformity, the relative geologic relation is clear, and the characteristics of sedimentary rocks are obviously different. Although the whole stratigraphic framework has not been affected due to the fault damage. The three sets of red beds stratigraphic system reflect the sedimentary environment and palaeogeomorphic evolution in different stages of the Meso-Cenozoic in the northern margin of West Qinling. In order to study the Meso-Cenozoic intracontinental tectonic process and the uplift of Qinghai-Tibet Plateau, The extended remote effects and other scientific issues provide the basic geological constraints.