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摘要
The Yongchun pluton is a Late Cretaceous adakitic intrusion in South Fujian Province, Southeast China, with associated metal mineralization. An understanding of the Yongchun pluton is helpful in tectono-magmatic evolutionary processes, and is important in explaining the origin of related porphyry-type deposits. Zircons from three samples of the pluton were analyzed by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), yielding U-Pb ages of 99.500.87Ma, 97.74 +/- 0.59Ma, and 99.65 +/- 0.92Ma. These ages are similar to those of the Sifang, Luoboling, and Sukeng plutons, all of which are related to Cu-Pb-Zn-Mo mineralization within the study area. The Yongchun pluton comprises high-potassium, calc-alkaline, metaluminous rocks, with average A/CNK values of 0.91, Sr-87/Sr-86 ratios of 0.705 51 to 0.706 83, epsilon Nd(t) values of -4.63 to -5.90, and two-stage Nd model (T-2DM) ages of 1.49-1.39Ga, indicating the magmas were generated by partial melting of Mesoproterozoic continental crust mixed with mantle-derived magmas. The pluton has geochemical characteristics typical of adakites, such as a high Sr content (average 553ppm), and low Y (average 15.2ppm) and Yb (average 1.61ppm) contents, indicating that the parental magma was formed under high-pressure conditions. The magmatism was associated with thickening of the lower crust during a change in subduction angle and convergence rate of the paleo-Pacific Plate at 100Ma. The compression was limited to South Fujian Province. @@@ ???,??????Yongchun???????????????????????,???????????.Yongchun????,????????????????????????,??????????(??)???????????????????.??????????????????LA-ICP-MS???????,???????????,????,99.50 +/- 0.87Ma,97.94 +/- 0.59Ma,99.65 +/- 0.92Ma????.???????Sifang?Luoboling???Sukeng???????????,?????????????????????.???????????????????????,??????(?Sr,?Y,Yb)??????,????????????????.???????????????????????????????????????????????????????????????????.
- 出版日期2018-3
- 单位中国海洋大学
