低温高压榴辉岩锆石Ti温度计的有效性  

The Validity of Ti-in-Zircon Thermometry in Low-Temperature/High-Pressure Eclogites

作　　者：蔺梦 张贵宾[1] 宋述光[1] 李慧娟 张丽娟 Lin Meng;Zhang Guibin;Song Shuguang;Li Huijuan;Zhang Lijuan(Key Laboratory of Orogenic Belts and Crustal Evolution,School of Earth and Space Science,Peking University,Beijing 100871,China)

机构地区：[1]北京大学地球与空间科学学院造山带与地壳演化重点实验室

出　　处：《地球科学》2019年第12期4034-4041,共8页Earth Science

基　　金：国家“973”计划项目(No.2015CB56105);国家自然科学基金项目(Nos.41972056,41622202,91755206);国家重点研发计划项目(No.2017YFC0601302)

摘　　要：为了探讨锆石的Ti温度计对于低温高压(超高压)榴辉岩的适用性,利用前人版本的温度计对北祁连和西天山4个典型低温高压(超高压)榴辉岩中的锆石进行了温度计算.结合其他地区高压/超高压榴辉岩锆石文献数据,发现对于低温变质锆石,Ti温度计得到的结果普遍高于其他温度计算方法,最高可达到58%.虽然温度是控制锆石中Ti含量的主要因素,但是其他因素(例如压力、SiO2和TiO2的活度,锆石中的晶格缺陷、其他微量元素替代、锆石的不平衡生长和变质流体活动)也会影响锆石Ti温度计的计算结果.研究认为,在锆石重结晶和再生长过程中,流体活动可能是造成锆石Ti温度计计算结果偏高的主要原因.In order to investigate the applicability of Ti-in-zircon thermometry to low temperature and high pressure eclogites,we used the calibration of other scholars to estimate the metamorphic temperatures for four typical low-temperature and high(ultrahigh)-pressure eclogites from North Qilian and western Tianshan,China.Compiled different HP/UHP eclogite samples from the literature,the Ti-in-zircon temperatures are generally higher than the estimations by other thermometers(up to 58%),especially for low-temperature metamorphic zircon.Although temperature exerts the dominant control on Ti content in zircon,other factors(e.g.pressure,TiO2 and SiO2 activity,lattice defect,other trace element substitutions,disequilibrium zircon growth and metamorphic fluids)also influence the calculated temperature results.This study proposes the metamorphic fluids may have contributed to the overestimated Ti-in-zircon temperatures.

关 键 词：错石 错石Ti温度计 低温高压(超高压)榴辉岩 变质流体 岩石学 

分 类 号：P595[天文地球—地球化学]