新西兰ROTORUA市KUIRAU热泉Na-K地球化学温标研究

Na-K地球化学温标在计算热储温度时，使用Na^ 、K^ 浓度的比值，因而地热水的混合稀释及蒸气损失对温度的计算影响不大。Na-K地球化学温标的依据是：在一定温度条件下，Na-feldspar(钠长石) K^ =K-feldspar(钾长石) Na^ 反应达完全平衡状态。但当热流体运动速度慢或被浅层地下水稀释而导致温度降低时，反应平衡会被打破，并形成新的平衡。新平衡形成之前为部分平衡状态。以新西兰著名的ROTORUA市KUIRAU公园热泉为例，讨论了在部分平衡条件下，Na-K地热温标的应用。

Na-K geothermometers study on springs in KUIRAU park, ROTORUA

Na - K geothermometer uses the Na/K ratio to calculate the temperature of reservoirs. It is less affected by dilution or steam loss. It derives from temperature dependant cation exchange reaction between Na and K-bearing feldspar: K + + Na - feldspar(albite) = K - feldspar(adularia) + Na+. It takes advantage of specific mineral -solute reactions which are slow to re - equilibrate at cooler temperatures. However, a slow rising fluid can re - equilibrate at shallower levels and cooler temperatures. Between two equilibrium conditions, the situation is called partial equilibrium. This paper discussed the applications of Na/K geothermometer in partial equilibrium conditions based on the spring chemistry of KUIRAU park, ROTORUA, NZ.