【摘要】 Rb-Sr同位素研究结果表明,哀牢山—金沙江带闪长岩、正长岩,分别为海西期(337Ma)和燕山晚期(83Ma);临沧—左贡带花岗闪长岩、黑云母花岗岩,为海西-印支期(263—193Ma);潞西—腾冲带斑状黑云母花岗岩、黑云母花岗岩,为燕山晚期(86—71Ma)。通过Sr、Nd同位素组成研究,对花岗岩成因进行探讨。更多还原

【Abstract】 Whole-rock Rb-Sr isochron ages of five plutons in the three petrographical belts of the Tri-River region are reported here. The results show that the ages of diorite and syenite from the Ailaoshan-Jinshajiang belt range from 337 to 83 Ma, corresponding to Hercynian and Late Yenshanian; those of granodiorite and inequigranular biotite granite from the Lincang-Zogang belt from 263 to 193Ma, equivalent to Hercynian to Indosinian; those of porphyritic biotite monzonitic granite and biotite granite from the Luxi-Tengchong belt from 86 to 71Ma, belonging to Late Yenshanian. Sr and Nd isoto-pic characteristics which can shed light on the origin of these granites are discussed as well.更多还原