1 State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing, China.
2 Research Center for Basin and Reservoir, China University of Petroleum, Beijing, China.
Appl Spectrosc. 2018 Jun;72(6):870-878. doi: 10.1177/0003702818761668. Epub 2018 Mar 6.
Apatite fission-track (AFT) analysis, a widely used low-temperature thermochronology method, can provide details of the hydrocarbon generation history of source rocks for use in hydrocarbon exploration. The AFT method is based on the annealing behavior of fission tracks generated by U fission in apatite particles during geological history. Due to the cumbersome experimental steps and high expense, it is imperative to find an efficient and inexpensive technique to determinate the annealing degree of AFT. In this study, on the basis of the ellipsoid configuration of tracks, the track volume fraction model (TVFM) is established and the fission-track volume index is proposed. Furthermore, terahertz time domain spectroscopy (THz-TDS) is used for the first time to identify the variation of the AFT annealing degree of Durango apatite particles heated at 20, 275, 300, 325, 450, and 500 ℃ for 10 h. The THz absorbance of the sample increases with the degree of annealing. In addition, the THz absorption index is exponentially related to annealing temperature and can be used to characterize the fission-track volume index. Terahertz time domain spectroscopy can be an ancillary technique for AFT thermochronological research. More work is urgently needed to extrapolate experimental data to geological conditions.
磷灰石裂变径迹（AFT）分析是一种广泛应用于低温热年代学的方法，可以提供烃源岩生烃历史的详细信息，用于烃类勘探。AFT 方法基于地质历史时期磷灰石颗粒中 U 裂变产生的裂变径迹的退火行为。由于实验步骤繁琐、费用高，因此迫切需要找到一种高效、廉价的技术来确定 AFT 的退火程度。本研究在轨迹的椭圆形状的基础上，建立了轨迹体积分数模型（TVFM），提出了裂变轨迹体积指数。此外，太赫兹时域光谱（THz-TDS）首次用于识别在 20、275、300、325、450 和 500℃下加热 10 小时的杜兰戈磷灰石颗粒的 AFT 退火程度的变化。样品的太赫兹吸收率随退火程度的增加而增加。此外，太赫兹吸收指数与退火温度呈指数关系，可用于表征裂变轨迹体积指数。太赫兹时域光谱可以作为 AFT 热年代学研究的辅助技术。迫切需要更多的工作来将实验数据外推到地质条件。
