高校地质学报2025，Vol.31Issue(6)：647-663,中插1-中插5,22.DOI:10.16108/j.issn1006-7493.2024096
南岭地区花岗岩体侵位—结晶年龄研究新思路:基于对花岗岩熔体的冷却过程和结晶潜热及放射成因热的计算
New Thinkings on Studying Emplacement-Crystallization Ages of Granitic Plutons in the Nanling Range:Based on Calculations of the Cooling Process,Crystallization Latent Heat and Radiogenic Heat of the Granitic Melts
摘要
Abstract
Based on the element diffusion theory and analysis to the experiment of U-Pb diffusion in zircon,it is confirmed that the"closure temperature of U-Pb isotope system in natural zircon>900℃"drawn from experiment of U-Pb diffusion in zircon by heating zircon crystals done by Lee et al.(1997)and Cherniak et al.(2000)can not be applied to the zircon crystallization process from the granitic melt.Using least squares regression procedure,a best regression equation(tZr=1.00346tAr-1.03511)with high correlation coefficient(R=0.996)is fitted for 514 pairs of zircon U-Pb age and hornblend-biotite Ar40/Ar39 age of granite plutons world wide.The PDF of the frequency analysis for these granite plutons shows symmetrical normal distribution with skewness coefficient(CSK)-0.16.These statistical characteristics cofirmed that the zircon U-Pb age can not represents the emplacement age of a granite pluton,but represent crystallization age also.According to the time difference elapsed from granite melt to crystallization,(ΔtECTD),these ΔtECTD(emplacement crystallization time difference)of 9 plutons were 52.0 my(Jiufeng),26.1 my(Xishan),28.6 my(Jingjiling),39.3 my(Guidongxiti),42.7 my(Qitianling),45.7 my((Huashan),42.7 my((Guposhan),9.74 my((Pitou),16.4 my(Zhaibei),respectively.Based on the zircon U-Pb ages,ΔtECTD of these granitoids and inversion calculation,these emplacement ages of 9 plutons in Nanling Rang were 219.4 my(Jiufeng),182.1 my(Xishan),184.6 my(Jingjiling),199.4 my(Guidongxiti),203.7 my(Qitianling),207.7 my(Huashan),205.7 my(Guposhan),192 my(Pitou),190.2 my(Zhaibei),respectively.These data contribute important evidences to the Indosinian cycle emplacement of the Early Yanshanian plutons in Nanling Rang and display the double magmatic-tectonic features in NR i.e.the E-W trending Indosinian tectonic framework(representing by tE)and the Early Yanshan granite plutons(representing by tC).关键词
南岭燕山早期花岗岩体/锆石U-Pb年龄/角闪石—黑云母Ar40-Ar39年龄/侵位年龄/侵位—结晶时差/印支造山运动Key words
Early Yanshanian pluton in Nanling Rang/zircon U-Pb age/hornblend-biotite Ar40/Ar39 age/emplacement crystallization time difference/emplacement age/Indo-Sinian Orogeny分类
天文与地球科学引用本文复制引用
章邦桐,凌洪飞,陈培荣,吴俊奇..南岭地区花岗岩体侵位—结晶年龄研究新思路:基于对花岗岩熔体的冷却过程和结晶潜热及放射成因热的计算[J].高校地质学报,2025,31(6):647-663,中插1-中插5,22.基金项目
内生金属矿床成矿机制研究国家重点实验室研究项目(2008-I-04)资助 （2008-I-04）
