The interactions between andesine grains (0.25―0.45 mm) and NaCl and KCl+NaCl solutions were experimentally studied under flow-through conditions (flow rates of solution: 7 ml/h and 1 ml/h) at 300oC and 50 MPa. For comparison, corresponding static runs were performed at the same pressure and temperature. All of these experiments were carried out in a flexible gold cell hydrothermal apparatus. The emphasis of the present study was laid on the changes in the composition of solid surface and solution chemistry at the early stage of the interaction. After the reaction an appreciable amount of etch pits and crystallites of alkali-rich feldspar appeared on the surface of the andesine. The statistical treatment of the SEM/EDAX data for the surface of the mineral reacted showed an increase in the atomic ratio of Si/Al, (K+Na)/Ca and (K+Na)/Al and a decrease in the ratio of Ca/Al, compared with the starting andesine. During the interactions, pH of solutions increased and considerable amounts of Si and Ca were transferred into the aqueous phase. In the NaCl solution experiment at a flow rate of 7 ml/h, the variations of the Si, Al, Ca and K concentration with time were very distinct. The static or "low" flow rate (1 ml/h) reaction conditions and the presence of KCl in solution seemed to hinder the release of Si in andesine to aqueous solution. It is concluded that alkali-metasomatism of andesine at flow-through condition involves the dissolution of the mineral, and the formation of alkali-rich feldspar.

Yugawaralite (CaAl2Si6O16.4H2O) occurs most commonly in active geothermal areas and is associated with other zeolites including laumontite and wairakite. The stability field of yugawaralite was experimentally investigated using conventional hydrothermal apparatus over a p-T range of 200-350℃ and 0.25―2 kbar and run duration of 14 to 61 days. The reversal experiments indicate that the p-T curve of the reaction yugawaralite = wairakite + 2SiO2 + 2H2O passes through 225±5℃ at 0.25 kbar, 233±5℃ at 0.5 kbar, 238±5℃ at 1 kbar and 245±5℃ at 2 kbar pfluid. The thermodynamic parameters of yugawaralite were calculated: 0 ΔSf = -2175.46±12.01 J/mol-K, 0 f ΔG = -8387.69±4.01 kJ/mol, 0 f ΔH =-9036.19±4.01 kJ/mol. The equilibrium curve, yugawaralite = laumontite + 2SiO2, was estimated by employing the thermodynamic data and the calculated slope of 31.3 bars/℃. Present and previous experiments define an invariant point where yugawaralite, wairakite and laumontite are stable. The invariant point was located at 234℃ and 550 bars in experimental conditions where H2O p =ptotal. In geothermal systems where H2O p is about 1/3 H2O p, the occurrence of yugawaralite is restricted to depths not much greater than 0.5 km. This result is consistent with its limited occurrence in active geothermal areas.

In order to verify the presence of residual organic matter in some S-type granites, a method used conventionally in petroleum geochemistry for isolation of kerogen was employed to separate carbonaceous material (CM) from the Xihuashan granite, Jiangxi Prov., China. Optical, XRD and SEM/EDAX analyses identified the acid-insoluble residue as mainly composed of various mineral debris, with a minor carbonaceous fraction found in the residue. LMR and micro-FTIR studies showed that the residue contained a small amount of CM, which is heterogeneous in composition and structural state. The occurrence of CM in the granite implies that this granitic magma originated from sediments and crystallized at relatively lower temperatures and high pressures. This deduction is consistent with geological and geochemical studies of the Xihuashan granite. A tentative model was suggested which connects CM in S-type granite with organic matter in sedimentary rocks. The conditions under which CM can be preserved in S-type granite are discussed. The occurrence of some heavy hydrocarbons is expected in the Xihuashan granite.

本文论述了在300℃，500 巴和溶液/岩石质量比为10的条件下用迪克森金袋和焊封小管技术研究了JB-2玄武岩玻璃-热液（蒸馏水、0.5%Na2CO3、0.5%NaHCO3、0.14%NaHCO3、二不同Cl-/HCO3比的NaCl-NaHCO3和0.1%NaCl溶液）反应中的溶液化学变化和蚀变矿物形成过程。结果表明，两种实验中得到的次生矿物组合基本相同；300℃和500巴时玄武岩玻璃-钠盐溶液（包括海水）反应实质上是玄武岩玻璃-水反应；碳酸盐离子使溶液中的钠含量降低以及形成次生碳酸盐。

本文于300℃，500bar时，用金袋式热液设备测定了MH（磁铁矿+赤铁矿）缓冲组合在HCl水溶液中的溶解度.计算了热水溶液中离子的活度，并用岭回归和叠代的方法处理实验数据，与多种可能的Fe存在形式模型拟合。结果表明，实验溶液中的 Fe 主要成 FeOH+存在。求得MH组合溶解反应的平衡常数K=57.161。计算了ΔG0f，FeOH+＝260.3kJ/mol。300℃时，在地质上可能的pH和氯化物浓度条件下，热液中的Fe主要成羟络合物存在。