辉绿玢岩中浊沸石及其成因

Laumontite in gabbroporphyrite and its origin

浊沸石产于鸡西盆地城子河组顺层侵入的辉长玢岩体中,呈放射状集合体并富集成条带,用X射线衍射、红外吸收光谱、电子探针3种方法对样品进行分析测定。结果表明:岩浆上侵冷却过程中形成的孔洞为浊沸石的形成提供空间条件,在孔洞周围发育的微裂隙,有利于CO2等气体散失的同时,也为岩体中长石提供Ca2+、Al3+离子进入孔洞中提供通道。Ca2+、Al3+离子在孔洞、孔隙溶液中发生化学反应,逐渐生成浊沸石、方解石,并逐渐沉积生长成集合体,生成浊沸石后的岩体可成为油气储层。

The laumontite occurs in the gabbroporphyrite bodies intruding concordantly strata of Chengzihe Formation of Jixi Basin. It crystallized as radiated aggregates and concentrated into bands. Three methods, including electron probe analysis, X-ray diffraction analysis and infrared absorption spectrum analysis, are used to analyze the samples. The results show that the cavities formed during the magmas intruding upwards and cooling prepared spaces for laumontite crystallization. In addition, the abundant microcracks developed around the cavities provided the passages or vents not only for gases escaping like CO2, but for Ca^2＋ , Al^3＋ , released out of the feldspathic minerals from the intrusion, migrating into the cavities as well. As a result of the chemical reaction in the solutions of cavities and holes, minerals like laumontite and calcite were formed. Gradually, they became enriched and concentrated as a form of radiated aggregates. The intrusion containing such laumontite could become the potential oil and gas reservoir rock.