Abstract: The Australian fan model is adopted as a quantitative model of apatite fission track annealing in this paper.The fission track annealing at various temperatures is deaIt with by using the equivalent time principle. The length distribution of a number of fission tracks produced at a short time is approximated with Gauss density function and the total fission tracklength distribution is derived from the summation of sub-distributions of length of fissiontracks produced successively in geohistory to accomplish the simulation of fission tracklength distribution along certain temperature time path.By integrating the fission track length distribution simulation(forward modeling),erosion amount and heat flow factor of the strata can be calculated by using two dimensional optimization method,then the systematic simulation of burial history,heat flow history andgeothermal history is realized and the heat flow history is obtained by progressive linear simulation method in sections from present to past.The numerical sirnulation method presentedin the paper has been applied to study the data from Well Qiu 3 in Linqing depression with areasonably good result.

Key words: apatlte, radioactivity, fission track, numerical simulation, formation, geological history, formation temperature

摘要： 选用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足够短时间内生成的一组裂变径迹之长度分布,通过地史上连续生成的各组裂变径迹长度分布叠加,来实现沿一定热史路径的裂变径迹长度分布模拟.将磷灰石裂变径迹长度分布模拟与地史热史模拟结合,用二维最优化方法求地层剥蚀量和热流因子,由此实现地史、热流史及地温史等的系统模拟,其热流史的计算采用从今到古的分段逐步线性模拟方法.本文中提出的数值模拟方法在临清坳陷丘3井进行了应用,模拟结果较合理.

关键词: 磷灰石, 放射性(裂变径迹), 数值模拟, 地层, 地质历史, 地层温度