作　　者： ; ; ; ; ;

机构地区： 中国科学院广州地球化学研究所边缘海地质重点实验室

出　　处： 《大地构造与成矿学》 2006年第2期241-247,共7页

摘　　要： 9个黑云母样品高精度^(40)Ar/^(39)Ar法定年结果表明,囊谦盆地高钾岩浆的活动年限为37.1~37.8Ma。高钾岩石在地质背景和岩石类型上与青藏东缘发现的两类高钾岩系中的早期高钾岩浆岩具有可比性,它们可能形成于相同的构造背景。结合前人的同位素年代学研究资料,金沙江-红河构造带南、北段高钾岩浆活动的时间分别为40~24Ma和40~33Ma,南、北段高钾岩浆活动时间的差异可能指示陆内俯冲作用时限的差异。 Nine newly obtained high-quality ^40Ar/^39Ar age data indicate that the high-K rocks in the Nangqian basin at the northern segment of the Jinsha - Red River Shear Zone （JRRSZ） were formed at the interval of 37.1 37.8 Ma. The high-K rocks in the Nangqian basin may temporally, spatially and compositionally be compared with the early one of the two-pulse high-K magmatic rocks distinguished by Wang et al. （2001） in eastern Tibet, which implies that they were formed in the same tectonic setting. Geochronologic dating and compilation of existing age data demonstrate that the magmatic activities occurred at the intervals of 40 - 33 Ma and 40 - 24 Ma respectively in the northern and southern segments of the JRRSZ. At the southern and the northern segments in the JRRSZ, the different geochronologic intervals for high-K magmatic activities indicate that the different time periods were controlled by continental subduction.

关 键 词： 新生代高钾岩石 年代学 金沙江 红河构造带 囊谦盆地

领　　域： [天文地球] [天文地球]