文章根据元素扩散作用理论及锆石中U和Pb扩散系数实验条件分析，认为Lee 等（1997）和Cherniak 等（2000）对锆石晶体中U和Pb扩散系数实验得出的 “天然锆石U-Pb同位素体系封闭温度>900 ℃”结论不能代表从花岗岩熔体晶出锆石过程的U-Pb同位素体系封闭温度。对国内外花岗岩体514对锆石U-Pb年龄与角闪石/黑云母40Ar/39Ar年龄进行相关分析及两种年龄差值（ΔtZr-Ar）频数统计分析表明：它们拟合出相关系数很高（R=0.996）的线性回归方程（tZr=1.00346tAr-1.03511)；两种年龄差值很小（众数值为0.7 my），偏度系数（CSK）为-0.16，概率密度函数曲线呈对称正态分布。这些特征表明：花岗岩体锆石U-Pb年龄与角闪石—黑云母40Ar/39Ar年龄基本一致，其表征的是花岗岩结晶年龄，而非侵位年龄。根据花岗岩熔体冷却结晶的时长计算得出南岭地区9个燕山早期花岗岩体的侵位—结晶时差（ΔtECTD）分别为：52.0 my（九峰）、26.1 my（西山）、28.6 my（金鸡岭）、39.3 my（贵东西体）、42.7 my（骑田岭）、45.7 my（花山）、42.7（姑婆山）、9.74 my（陂头）、16.4 my（寨背）。根据各岩体的锆石U-Pb年龄及其侵位—结晶时差（ΔtECTD），通过反演计算得出的侵位年龄分别为: 219.4 Ma（九峰）、182.1 Ma（ 西山）、184.6 Ma（金鸡岭）、199.4 Ma（贵东西体）、203.7 Ma（骑田岭）、207.7 Ma（花山）、205.7 Ma（姑婆山）、192 Ma（陂头）、190.2 Ma（寨背）。这为南岭燕山早期花岗岩体属于印支期侵位及该区印支造山运动提供了重要佐
证，揭示出近东西向展布的南岭晚中生代造山带具有印支期构造格架（以侵位年龄为代表）和燕山早期花岗岩（以锆石U-Pb年龄为代表）的双重特征。

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).