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Analysis Of Tectonic-Palaeogeographic Variance Of The Caledonian Movement And Oil-Gas Exploration Potential In The Dian-Qian-Gui Area

Posted on:2006-02-11Degree:DoctorType:Dissertation
Country:ChinaCandidate:H LiFull Text:PDF
GTID:1100360155951288Subject:Mineralogy, petrology, ore deposits
Abstract/Summary:PDF Full Text Request
Strongly controlled by the Coledonian movement, the study area, i.e. the Yunnan-Guizhou-Guangxi area, has undergone a complex evolution of tectonic-palaeogeographic process from the Cambrian to the Devonian. This complex process is resulted from the crust uplift generated by tectonic movement, that is, the Yunan movement occurred at the turn from the Cambrian to the Ordovician, the Duyun movement occurred at the turn from the middle to late Ordovician and the Guangxi movement occurred at the turn from the Silurian to the Devonian. These tectonic movements belong to the first to the third episodes of the Coledonian movement respectively. After a rapid transgression at the transitional period from the Sinian to the Cambrian, the study area became a great sea. As a result of this great-sea setting, the lower-Cambrian source rock that widespread distribute in the study area was formed. The crust uplift caused by the Yunan movement at the turn from the Cambrian to the Ordovician led to an incipient shape of the Dianqiangui oldland in the central part of the study area. The study area became a great oldland after the Duyun movement in the end of the middle Ordovician; therefore, the Dianqiangui oldland was formed from the late Ordovician to the early period of the Silurian. Although the southward transgression in the Silurian had partly disintegrated the Dianqiangui oldland, the distributional situation both land and sea in the study area had not undergone a great change. Resulted from the Guangxi movement occurred in the end of the Silunian, the study area became a great oldland again in the late period of Silunian. Ultimately, the results of these three tectonic movements are the southward dieing out of the upper Ordovician and the Silunian strata, the partly development both the Ordovician and the Silunian strata and a complex unconformity of the Coledonian movement in the study area. The northward slow transgression in the Lochkovian and the Pragian of the Devonian formed a set of transgressive sandstone system. This set of transgressive sandstone system direct covers on the strata from the Cambrian to the Silunian. After the Emsian large-range transgressive event, a particular sedimentary basin, i.e. the Dianqiangui Basin marked by a setting of "platform-basin-hill-trough"was formed in the study area. The Devonian System in the Dianqiangui Basin can be grouped into 13 third-order sequences. Beside the lower-Cambrian source rock, another set of good-quality source rock of the middle Devonian was formed in the starve-basin...
Keywords/Search Tags:tectonic-palaeogeographic evolution, Devonian sequence stratigraphy, analysis of oil-gas exploration, the Yunnan-Guizhou-Guangxi area
PDF Full Text Request
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