This paper has reported the first application of 40Ar/39Ar dating to orthoclase from Oitianling granite. The resultant plateau ages yielded by three orthoclase specimens 2KL-17, 99LQ-2 and 2KL-31 (Note: The last one w...This paper has reported the first application of 40Ar/39Ar dating to orthoclase from Oitianling granite. The resultant plateau ages yielded by three orthoclase specimens 2KL-17, 99LQ-2 and 2KL-31 (Note: The last one was taken from the part of granite which had been attrib-uted to Cailing super-unit of the Indosinian Period by the former researchers) collected from the said granite are (139.57±.79) Ma, (140.55±.81) Ma and (144.91 ±.90) Ma respectively. The above-mentioned ages represent the closed 40Ar/39Ar age of the orthoclase. The consistency in age dating results, the similarity in geochemical characteristics and rock textures, and the Nw-SE orientation of orthoclase phenocrysts almost throughout the granite, provide evidence for the inti-mate relationship between the Furong super-unit and the Cailing super-unit that form the main part of the granite, suggesting that they are products of comagmatic conjugate differentiation during the Late Jurassic. This paper also makes a comparison between the ditianling granite and the Qianlishan granite.展开更多
文摘This paper has reported the first application of 40Ar/39Ar dating to orthoclase from Oitianling granite. The resultant plateau ages yielded by three orthoclase specimens 2KL-17, 99LQ-2 and 2KL-31 (Note: The last one was taken from the part of granite which had been attrib-uted to Cailing super-unit of the Indosinian Period by the former researchers) collected from the said granite are (139.57±.79) Ma, (140.55±.81) Ma and (144.91 ±.90) Ma respectively. The above-mentioned ages represent the closed 40Ar/39Ar age of the orthoclase. The consistency in age dating results, the similarity in geochemical characteristics and rock textures, and the Nw-SE orientation of orthoclase phenocrysts almost throughout the granite, provide evidence for the inti-mate relationship between the Furong super-unit and the Cailing super-unit that form the main part of the granite, suggesting that they are products of comagmatic conjugate differentiation during the Late Jurassic. This paper also makes a comparison between the ditianling granite and the Qianlishan granite.
