HE Huaiyu,GUO Zhengfu,WANG Songshan,HAO Jie,LIU Qiang Institute of Geology and Geophysics,Chinese Academy of Sciences,P.O. Box 9825,Beijing 100029,China,and Ariel BOVENLaboratory of Geochronology,Vrije Universiteit Brussel,Pleinlaan 2,1050 Brussels,Belgium
The dike swarm of lamprophyres at Pishan on the SW margin of the Tarim terrane is composed of ultra-potassic lamprophyres that have intruded into the Proterozoic hornblende schists. 40Ar/39Ar dating data suggest that the isochron ages for phlogopite and whole rock separates of the lamprophyres are 231.7±0.3 Ma and 228.5±0.3 Ma, respectively. Geochemical data indicate that the dikes were derived from a subduction-related or metasomatized mantle. During the Middle-Late Triassic the western Kunlun area entered the post-orogeny period, and thus the occurrence of the dike swarm in the study area may have been controlled by underplating.
Abstract:
The dike swarm of lamprophyres at Pishan on the SW margin of the Tarim terrane is composed of ultra-potassic lamprophyres that have intruded into the Proterozoic hornblende schists. 40Ar/39Ar dating data suggest that the isochron ages for phlogopite and whole rock separates of the lamprophyres are 231.7±0.3 Ma and 228.5±0.3 Ma, respectively. Geochemical data indicate that the dikes were derived from a subduction-related or metasomatized mantle. During the Middle-Late Triassic the western Kunlun area entered the post-orogeny period, and thus the occurrence of the dike swarm in the study area may have been controlled by underplating.
Ariel BOVEN.2003.~(40)Ar/~(39)Ar Age and Geological Significance of Lamprophyres in Pishan on the SW Margin of the Tarim Terrane, NW China[J]. ACTA GEOLOGICA SINICA(English edition),77(1):
