天水地震区深源岩石在1000MPa高压下的状态参数特征

THECHA RACTE RISTICSOF DEEP-SEA TE DROCK'S STA TEPARAMETER SIN TIANSHUIEARTHQUAKEREGIONUNDER HIGHPRE5SUR EUPTO1000MPa

本文重点介绍了天水地震区产出的深源岩石在１０００ＭＰａ高压下，测得的岩石的密度、纵横波速度和计算的波阻抗随压力的变化。发现不同时期产出的不同种类的深源岩石，它们的高压状态参数值变化范围很窄。压力上升到４００ＭＰａ以后，岩石的密度、纵横波速度的变化很小，几乎观测不到其变化。本文简单地讨论了岩石在４００ＭＰａ以上高压状态下，上述参数值变化不大的原因，并对４００ＭＰａ压力下取得的高压状态参数值做了实用误差分析，结果表明：在不考虑温度情况下，该压力下获得的状态参数值在实际应用中完全可以代替更高压力状态下（４００ＭＰａ－２０００ＭＰａ）的测量值。因此４００ＭＰａ特征压力下取得的岩石状态参数值对人工地震测深解释和重力解释仍是有参考意义的。

In this paper,we discussed mainlythe variation of the rock density,S&Pwave speed andcalculated wave resistance with the pressure up to 1 000MPa. These deep-seated rocks werecollected in Tianshui earthquake region. It was found that the state parameters of differentkinds of deep-seated rocks,which didn’t form at the same time,changed very little underhigh pressure. After the pressure up to 400 MPa,the variation of the rock density and S&Pwave speed almost can’t be found.We simply discussed the reasons of the phenomenon,andmade practical error analysis on the parameters under 4 0 0 MPa pressure,The resuIt showsthat,without considering tempreture,the state parameters which were gained under 400 MPapressure can completely replace the parameters under higher pressure(400 MPa-2000MPa)in practical application. so the rock state parameters(under 400 MPa characteristic pressure)are still significant for the artificial deep seismic sounding explanation and gravitation explana-tion.