Trace Elements Characteristics And Geological Application Of Qianfoya Formation Of Jurassic In Bazhong Area,Sichuan Province

For the investigation of outcrop sections and cores of the four wells,the previous results based on petrological and geochemical data including;logging data,core data,and thin sections were used to understand the specific petrological and geochemical characteristics in248 fresh rock samples.Then through accurate analysis and testing,the types and contents of specific elements contained in the rock samples are obtained,and based on the theoretical results obtained by the predecessors,through analysis and comparison,we find representative and sensitive elements to various sedimentary factors.By the comparison of analysis and theoretical results,we obtained the types and contents of specific elements in the rock samples with various sedimentary factors.The specific changes in the study of their migration and enrichment characteristic in sedimentary environments has inverted the geological characteristics of the study area during deposition.By this study,the following conclusions are:(1)Through the study of the ratio of V/Cr and V/(V+Ni)represents the restoration of paleo-redox conditions can be carried out.Through research and by the analysis,it ihas been found that the study area is generally in a sedimentary environment with partial oxidation.and the The water in the southern part of the study area is deep,and the reduction was is stronger than that in the northern part.During the entirein the Qianfoya Formation,the water level in the study areais changed from low to high and then low.experienced low-high-low changes.At the same time,in the study area,as athere are also continental deposits after excluding the influence of the river,the The V/Cr ratio(3-3.5)can also be used between 3-3.5 to indicate the boundary of subaqueous environment and terrestrial environment;(2)The content of the Rb/Sr ratio and their variation characteristics of the Rb/Sr ratio in each region can reflect the paleo-humidity characteristics of the study area.The present study has been found that the humid regions are from the northeast and northwest in the Qian ?period,to from the northeast direction and the north in the Qian ? period,and then to from the north of the Qian ? period.(3)By comparing the content of Y element and Zr element,and combined with the analysis of the ancient humidity,redox conditions and their provenance directions,the provenance direciton of the research area can be depicted accurately.The research shows that the main provenance direction of the study area is from the direction of Longmen Mountain in Qian ? period,and then changed to the direction of Micang Mountain into Qian ? and Qian ?period.(4)Considering the influence of the provenance and redox conditions,the P content can be used to approximate the activity of paleontology in the continental sedimentary environment,so that the paleo-sedimentary environment can also be depicted.The above conclusions can be comprehensively used to complete the verification and improvement of the specific plane phase distributions of the study area.