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Discovery of High-Pressure Basic Granulite Terrain in North China Archaean Craton and Preliminary Study 总被引:2,自引:0,他引:2
High-pressure basic granulite terrain of 2.65 Ga from Jiouhuai'an in the junction of the Hebei and Shanxi provinces was discovered and reported recently. The three metamorphic mineral assemblages and their mineral reaction texture of the basic granulites have been identified, which represent three main metamorphic episodes of 1.4—1.5 Gpa, 800℃; 0.7—0.9 Gpa, 820℃ and 0.5—0.6 Gpa, 700℃. Their steep decompressional clockwise P-T path implies that a late Archaean continental collision and sole thrusting event perhaps occurred in North China Craton. This is important to study petrogenesis of high-pressure granulites, composition and texture of deep crust in North China Craton, and early Precambrian collision tectonism. 相似文献
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142Nd/144Nd比值的超高精度测定技术对于研究太阳系早期演化及月球-地球早期硅酸盐分异具有重要应用价值.本实验利用热电离质谱(TIMS)开展142Nd/144Nd比值的超高精度测试研究,并对比了动态多接收和静态多接收两种测量方式.结果表明,动态模式具有更高的准确度和精密度.讨论了影响测试精度的各种因素,在此基础上通过优化测试条件,对国际标准(Jndi-1)的142Nd/144Nd测试结果为1.1418348,外部精度优于5×10-6(2SD), 完全满足146Sm-142Nd体系研究的技术要求. 相似文献
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