【摘要】 不同温度和压力条件下,与碎屑岩成岩作用中浊沸石形成有关的两个反应吉布斯自由能增量(△G)的计算结果说明,埋藏成岩条件下斜长石蚀变(斜长石、石英和水反应)形成浊沸石的反应在温度大于36℃的条件下就可以进行(按埋藏深度2000m,正常压力梯度考虑相应压力),而高岭石与方解石反应形成浊沸石(同时有石英和水参与)所需的最低温度为170℃(埋藏深度2000m,正常压力梯度考虑相应压力);与温度相比,压力对碎屑岩成岩作用中浊沸石的形成影响较小。因而沉积岩成岩过程中形成的浊沸石主要与斜长石蚀变有关,同时也不应将浊沸石一概作为低级变质作用的产物。更多还原

【Abstract】 We calculate the increment of Gibbs free energy (AG) of the two chemical reactions for the formation of laumonite related to clastic diagenesis under different temperatures and pressures. The result of calculation shows that the temperature needed for the formation of laumonite by alteration of plagioclase (reaction of plagioclase, quartz and water) is more than 36℃ only (burial depth: 2000 m and normal pressure gradient). However, the temperature needed for the formation of laumonite by the reaction of kaolinite, calcite, quartz and water should be more than 170℃ (burial depth- 2000 m and normal pressure gradient). The pressure needed for the formation of laumonite is not as important as the temperature. So the origin of laumonite related to clastic diagenesis is mainly from the alteration of plagioclase. We could not use the laumonite as the boundary for separating diagenesis from burial metamorphism.更多还原