磷灰石裂变径迹分析（AFTA）──一种研究含油气盆地古热构造史的新方法

Apatite Fission Track Analysis:A New Tool for the Research of Thermal and Tectonic History in Petroliferous Basin

磷灰石裂变径迹分析（ＡＦＴＡ）近年来广泛地被用来研究含油气盆地古热史与古构造史及指导油气勘探，这主要是根据磷灰石裂变径迹退火是时间和温度的函数，而烃的生成与热成熟同时也是时间和温度的函数，而且磷灰石裂变径迹退火温度范围与石油的生成门限相吻合。退火除受温度、时间影响外，还受化学成分、取向因素控制。ＡＦＴＡ包括裂变径迹年龄分析和裂变径迹长度分析，通过前者可获得退火方面信息，通过后者可获得最大古地温及其随时间的变化及热史类型等方面的信息，二者的有机结合可获得热构造史的完整信息。长度分析有封闭径迹和投影径迹长度分析两种。

Apatite Fission Track Analysis(AFTA) has been applied to the research ofthermal and tectonic history in petroliferous basin,as well as to direct oil-gas exploiting illrecent years. This technique depends on the observation that annealing of fission track inminerals, resembling the generation and maturation of hydrocarbons, is a function oftemperature and time,and that the temperature interval over which track anneals in apatiteis identical with that required for the maxium generation of liquid hydrocarbons.Excepttemperature and time,annealing is also subjected to apatite composition and track's anglewith C-axis. AFTA technique is composed of the two parts, Age analysis and LengthAnalysis. In research of Age Analysis we can get the annealing information. In research ofLength Analysis we can get the information about the maxium pale-temperature; itsvariation along with time and as well as thermal types. By combining the two types analysiswe can get integrated information about thermal and tectonic history. Length Analysiscontains confined Length Analysis and Projected length Analysis.