The Formation and Geological Significance of the Pengshan Dome in Jiangxi Province
To investigate the genesis and the age of the Pengshan dome,field geological surveys,structural analy-ses,and chronological studies were conducted in Pengshan area.The results show that the Pengshan dome is a tectonic dome with a short axis anticline in shape.There is a stable Indosinian-period paleotectonic stress field ori-ented nearly SN in and around the dome,associated with NNE-trending strike-slip faults,and an eastward-dipping thrust fault on its eastern side.Felsite porphyry dykes have intruded the faults which cut through the dome.The zircon U-Pb age of the felsite porphyry dykes is(123.0±1.0)Ma,the U-Pb age of the underlying rock mass is(123.0±1.4)Ma,and the illite K-Ar age of the fault gouge in the paleostress field is(228.1±10.3)～(233.2±6.5)Ma.Therefore,the formation time of the Pengshan dome is Indosinian or earlier.
万方数据
维普
