压力对磷灰石裂变径迹退火的影响初步探讨

磷灰石裂变径迹分析技术是确定岩石低温热历史的一种有效方法，其退火后径迹长度受多种因素影响，如温度、压力、磷灰石的化学成分、径迹与结晶C轴的夹角、蚀象直径（D_par）以及年龄等，但压力的影响很少有文章论述.在调研大量国内外资料的基础上，通过将统计后的数据作图来阐明压力对径迹退火的影响.研究结果表明压力对径迹的退火具有重要影响，压力越大，退火后得到的径迹长度越短，且随着压力的增大，径迹变短的程度也在增大.当压力小于150 MPa时，压力的影响可以忽略，这时径迹退火主要受温度影响.压力和温度在磷灰石裂变径迹退火时起到相互弥补的作用，即高压、低温与低压、高温都能达到相同的退火程度.

PRELIMINARY DISCUSSION ON THE IMPACT OF PRESSURE ON FISSION TRACK ANNEALING OF APATITE

Fission track analysis of apatite is an effective method to determine low temperature thermal history of rocks. The track length after annealing is affected by many factors such as temperature, pressure, chemical composition of apatite, the included angle between track and crystallographic C axis, etched diameter (D_par) and age, but there are few articles about the effect of pressure. Based on a large number of domestic and oversea literatures, the authors illustrate the effect of pressure on track annealing by plotting the statistical data. The results show that pressure has significant effects on track annealing:The greater the pressure is, the shorter the track length after annealing is. With the pressure increasing, the degree of shortened track also increases. When the pressure is less than 150 MPa, the influence of pressure may be negligible, and the track annealing is mainly affected by temperature. Pressure and temperature complement each other in the fission track annealing of apatite, namely, high pressure with low temperature, or low pressure with high temperature, can all achieve the same degree of annealing.