ORIGIN OF THE IGNEOUS ZIRCONS: Constraints from Morphology and Trace Element Chemistry
ZHANG Hong-fa1, CHEN Gang1, BAO Hong-ping2, WANG Run-san1, PENG Tian-lang1
1. State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China; 2. Institute of Oil and Gas, Changqing Oil Field, Xi'an 710003, China
Abstract：Detailed study on the morphology and trace element chemistry of the Zijinshan alkaline complex reveals that there is no igneous zircon in the phonolitic, trachytic and volcanic breccia, with minor xenocryst zircons in the purple and white phonolite and trachyte porphyry. LA-ICP MS analysis results indicate that there are five stages for the formation of these zircons, i.e. Archean, Paleoproterozoic, Late Paleozoic, Early Mesozoic and Late Mesozoic. Most of the zircons present as xenocrysts, which show erosion textures in the CL images. Trace element chemistry suggests a complex crystallization process for the zircons in sub-alkaline rocks, with REE patterns characterized by multi-stage crystallization and alteration. It is concluded that the zirconium is unsaturation in the alkaline magma, with all the xenocrysts corroded. The zircon in the overflow facies magma just reaches the critical point of saturation, so there is no igneous zircon in these melts.
张宏法, 陈刚, 包洪平, 王润三, 彭天朗. 火山岩锆石产状及痕量元素对成因的约束[J]. 地质与资源, 2013, 22(1): 67-75.
ZHANG Hong-fa, CHEN Gang, BAO Hong-ping, WANG Run-san, PENG Tian-lang. ORIGIN OF THE IGNEOUS ZIRCONS: Constraints from Morphology and Trace Element Chemistry. GEOLOGY AND RESOURCES, 2013, 22(1): 67-75.
2013, Vol. 22 
辽公网安备 21010502000112号