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攀西层状基性-超基性岩侵入体富含大型钒钛磁铁矿床,对其已进行过详细研究。但是岩体的形成时代一直存在争议。本文采用Sm-Nd同位素年代学方法对攀枝花、白马、红格岩体的年龄进行了研究。获得的年龄结果表明,岩体形成于晚海西-印支期,年龄283～197 Ma。红格岩体283±38(2σ)Ma,白马岩体197±60(2σ)Ma,攀枝花岩体上部岩相旋回210±43(2σ)Ma,下部岩相旋回282 Ma左右。攀西层状基性-超基性岩体与峨眉山玄武岩大致形成于同一时期。
The Panzhihua stratiform basic-ultrabasic intrusive rock is rich in large vanadium-titanium magnetite deposits and has been studied in detail. However, the formation of rock mass has been controversial. In this paper, the ages of Panzhihua, Baima and Honggeitic rocks were studied by Sm-Nd isotope geochronology. The obtained age results show that the rock mass was formed in the Late Hercynian-Indosinian period with an age of 283-197 Ma. 283 ± 38 (2σ) Ma for the red rock mass, 197 ± 60 (2σ) Ma for the Baima rock mass, 210 ± 43 (2σ) Ma for the upper lithofacies of the Panzhihua massif, and 282 Ma for the lower lithofacies. Panxi stratiform basic - ultramafic rocks and Emeishan basalts generally formed in the same period.