Main Elements Geochemistry Implication of Meso-Cenozoic Tectonic Evolution

Abstract

The apatite and zircon fission track (FT) analysis offers the opportunity to reveal the chronology records for Meso-Cenozoic tectonic events in the Northeast of Ordos Basin, China: the Indosinian Epoch tectonic events mainly occurred at (245-235 Ma±) with a peck-age of 240 Ma and (205-195 Ma±) with a peck-age of 200 Ma, corresponding to the parallel unconformity during the Middle and Lower Triassic to Upper Triassic, the angular unconformity during the Late Jurassic to its underling layers. Middle Yanshanian tectonic events occurred at (155-115 Ma±) with a peck-age of 135 Ma, and corresponded to the angular unconformity during Lower Cretaceous to its underling layers. Late Yanshanian to Himalayan tectonic events included at least two episodes, peak-age respectively is (65Ma±) and (20 Ma±). On this basis, we further complete their main elements geochemical analysis. The contents of TiO₂, Fe₂O₃+MgO, Lg (SiO₂ / A1₂O₃) in samples was 0.18-1.02%, 1.23-8.55%, and 0.59-1.04%, respectively. The average was 0.53%, 4.5%, 0.71%, respectively. Based on the discriminant plate of the main element, the transition events of the important sedimentary structure environment in phase two were obtained. The relationship analysis of the tectonic event and the mineralizing chronology revealed that the key tectonic events control reservoir forming time or mineralization time of the coupling coexistence of multiple energy resources in the Northeast of Ordos Basin, and show the collaborative and coupled relationship between the tectonic events and accumulation (mine).