摘要
在1.0GPa、常温至1100℃条件下测量了角闪石斜长片麻岩的纵波速度(V_P),并统计了不同温度实验产物中各种矿物的体积百分含量。结果显示,1.0GPa下,角闪石斜长片麻岩的V_P首先随温度升高(室温至700℃)缓慢降低约6%,然后(700～850℃)快速降低约6%,再(850～950℃)转而急剧升高15%～25%,最后(T>950℃)又快速下降。实验产物分析表明在高温高压下α石英-β石英相变和岩石部分熔融是岩石V_P异常变化的主要因素。由取样产物的矿物含量和弹性参数,计算了各温度条件下岩石的V_P,得出与实验测量相同的波速-温度变化趋势,即V_P随温度升高先缓慢降低,接着快速降低后又急剧升高,最后又快速减小。实验测量和理论计算对比研究表明,通过高温高压下岩石中的物相变化观测结果进行岩石波速的计算,是检验岩石弹性波速测量结果和研究地球内部地震波结构的一种有效方法。
Compressional wave velocity （ Vo ） for hornblende plagiogneiss was measured at 1.0GPa and up to 1100℃. The volume percentages of minerals were investigated in the run products, which were gained under 1. OGPa and at different temperature. The results show that at 1.0GPa, Vp of hornblende plagiogneiss decreases slowly （ 6% ） up to 700℃, and decreases quickly （ 6% ） from 700 to 850℃ , and then increases sharply （ 15% - 25% ） from 850 to 950℃ , and decreases quickly again from 950 to 1000℃. According to the investigations on products, we hold that the α-13 transition of quartz and partial melting of specimen are responsible for the variation of Vp. With the volume percentages of minerals and their elastic parameters, the temperature variation of velocities for specimen are calculated by using Voigt-Reuss-Hill （VRH） model. The calculation shows a same temperature trend of Vp with experiment run, which shows the Vp, with increasing temperature, decreases slowly at first, and then decreases quickly followed by a sharp increase, and then decreases quickly again. From this work, it is believed that according to the investigation on phase transformation in rock, we can calculate the velocities of rock at different pressure and temperature, which is an effective method for testing experimental results and for studying earth＇s seismic structure.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2008年第10期2441-2446,共6页
Acta Petrologica Sinica
基金
国家重点基础研究发展计划项目(No2005CB724400)
中国科学院知识创新工程重要方向项目(KJCX2-SW-N20)
国家自然科学基金项目(40574036)
贵州大学引进人才科研基金资助
关键词
角闪石斜长片麻岩
高温高压
纵波速度
相变
部分熔融
Hornblende plagiogneiss
High pressure and high temperature
Compressional wave velocity
Phase transformation
Partial melting
