塔里木盆地深层沉积物石英E′心热力学特性

Thermodynamic behavior of E′centers in quartz from deep sediments, Tarim basin

热活化技术通常以石英E′心的信号强度代替石英氧空位心的相对浓度 ,测定石英E′心的寿命时也使用热活化技术。在进行塔里木盆地TK3 0 1井深层 (深度 4895～ 5 10 2m)二叠系沉积物的ESR研究时 ,发现石英E′心的信号经 3 0 0℃热活化3 0min后不见增长 ,直至 5 0 0℃时才显著减少。这一观测结果和Toyoda的实验结论相一致 ,表明尽管石英氧空位的形成效率比较低 ,但是在环境物质的 β和γ剂量长时间辐射作用下可以生成氧空位心。在深层沉积物的ESR测年实验中 ,可以直接用石英E′心的ESR信号代替氧空位心的相对浓度。

abstract The intensity of E′centers may be used instead of the relative amount of oxygen vacancies usually by thermal activation technique, and the life estima tion of E′centers is also carried out by the thermal activation technique. In t he ESR research of deep sediments (4895-5102m, Permian System) from Well TK301, Tarim basin, the authors found that the intensity of E′centers in quartz did no t increase after heating at 300℃ for 30min and decreased greatly up to 500℃. This obse rvation is consistent with the experimental result of Toyoda (1994). Although th e formation efficiency of oxygen vacancies is very low, but the external β and γ rays of environmental matter may create oxygen vacancies in natural q uartz during the long time. The intensity of E′ centers in quartz from deep sed iments can be directly used instead of the relative amount of oxygen vacancies, the experimental process of ESR dating can be simplified.