The Formation And Evolution Of Kaijiang Paleo-uplift In Eastern Sichuan Basin

Kaijiang paleo-uplift as one of the three major paleo-uplift of Sichuan Basin,Based on the seismic exploration data,fine interpretation the geological structure of East Sichuan Kaijiang paleo-uplift.In geological structure interpretation according to establish geology geometry model,to analyze the evolvement process and tectonic deformation mechanism and tectonic deformation mode structure in East Sichuan,the simultaneous analysis of multi detachment folds-thrust fault belt of tectonic deformation influence on the regional tectonic style.From the study on the integration of regional and local,plane and profile,of East Sichuan Kaijiang paleo-uplift of the formation and evolution,to analyze the relationship of oil and gas,achieved results are as follows:(1)Important unconformity is development in east Sichuan,including: the regional parallel unconformity between the late Triassic and underlying Middle Triassic,the regional parallel unconformity between late and early Permian,the regional parallel unconformity between the Permian and the underlying Carboniferous,the regional parallel unconformity between the Cambrian and the underlying Sinian.(2)After complex tectonic movement deformation,Kaijiang has obvious characteristics of stratification structure,the lower basement involved positive inversion structure,the upper is a thin skinned structure fault grounding in the Cambrian and Silurian detachment layer,jointly controlled the development of surface folds.Development of positive inverted structure,detachment fold,fault bend fold,fault propagation fold,imbricate thrust structure,pop up and so on.(3)Kaijiang paleo-uplift is a inherited paleo-uplift,stereotypes in Late Triassic Indosinian,the evolution is divided into four phases: Caledonian-Maokou Formation sedimentary period,due to the Leshan-Longnvsi paleo-uplift,the ancient uplift control function,high in the whole west and low in the Sichuan basin,northeastern Sichuan basin is slope;Changxing to Feixianguan sedimentary period,the northeast of Sichuan is a slope shape,Kaijiang paleo-uplift is a local high point,at the same time,Kaijiang to Liangping become northwest trending Kaijiang-Liangping Trough;Jialingjiang to Leikoupo formation sedimentary period,in east Sichuan basin Kaijiang paleo-uplift has formed basically.Indosinian and Himalayan period,Kaijiang paleo-uplift subjected to dissolution,transformation.(4)The formation of Kaijiang paleo-uplift has obvious control the evolution of source rocks,reservoir,oil and gas accumulation.Dongwu movement influence Kaijiang paleo-uplift produced differential subsidence,controlled the distribution of Late Permian Longtan formation deposition,the impact of the Longtan formation hydrocarbon source rock development;Yunnan movement makes the Huanglong formation of Carboniferous uplift and denudation.Huanglong formation karst reservoir forming karst highland;Kaijiang paleo-uplift has repeatedly strong weathering and denudation,making unconformity become the predominant pathway of oil and gas migration...