磷灰石裂变径迹长度分布数值模拟及地质应用

NUMERICA LMODELLING ON THE LENGTH DISTRIBUTIONS OF APATITE FISSION-TRACKS AND ITS APPLICATIONS IN GEOLOGY

选定澳大利亚扇形模型为磷灰石裂变径迹退火定量模型，依据等价时间原理处理裂变径迹的变温退火，用高斯密度函数逼近一足够短时间内生成的一“组”裂变径迹长度分布，通过地史上连续生成的各组裂变径迹长度分布叠加．实现沿一定热史路径的磷灰石裂变径迹长度分布模拟。通过沿若干种地质概念热史路径的磷灰石裂变径迹长度分布数值模拟及比较，为沉积盆地热史分析提出了一些定性判断模式，并以此为基础，进一步模拟盆地地史和热史。最后用此方法分析并模拟了丘３井的热史地史及地层剥蚀量。

In tbe paper,the fan model from Australia is adopted as a quantitative model of ap-atite fission-track annealing. The authors modelled the length distribution of apatite fis-sion-tracks along certain temperature-time paths on the basis of fission-track annealing atvariable temperatures using the equivalent time principle;the length distribution of a se-ries of fossion-tracks produced at a sufficient short time being approached by a Qatiss den-sity function;and the superimposed length distributions of fission-tracks prodticed succes-sively throughrout geohistory.Some qualitatively discriminant models,herein for theanalysis of geothermal history of sedimentary basins,are presented by numerical mod-ellings on the distributions of apatite fission-tracks along several geothermal temperaturepaths and their correlations. It is proposed that a further modelling on the geohistory andgeothermal history sedimentary basins can be achieved with such a discriminant model andfinanlly,the numerical modelling is applied for the thermal history and stratigraphic de-nudation of Qiou No. 3 well.