Abstract A mordenite-rich deposit located in the south of the province of Mendoza (Argentina) was studied. The host rock in this area has not been previously described and corresponds to rhyolitic lavas of high-K calc-alkaline series. Petrographic, mineralogical and geochemical analyses of fresh and altered rocks are shown, and a proposal for the alteration process and the stratigraphic position of the protolith is presented. The main mordenite-rich sectors developed in zones of autobreccias of high permeability, with minor clinoptilolite, smectites, secondary K-feldspars, opal-CT, and colloform silica. The proportion of relict glass vs. alteration minerals is variable and mainly depends on the texture (permeability) of the host rock. The studied rhyolites overlie the Upper Cretaceous sediments of the Neuquen Group and are covered by Tertiary basalts of the Molle Eruptive Cycle and Quaternary sediments. Geochemically, they present similarities with rhyolitic rocks of Cordon del Burrero Volcanic Complex of Lower to Middle Miocene age.

中文翻译：

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酸性玻璃质岩中的沸石，阿根廷门多萨南部

摘要 研究了位于阿根廷门多萨省南部的一个富含丝光沸石的矿床。该地区的主岩以前没有被描述过，对应于高钾钙碱性系列的流纹岩熔岩。显示了新岩石和蚀变岩石的岩石学、矿物学和地球化学分析，并提出了对蚀变过程和原岩地层位置的建议。主要的富含丝光沸石的部分发育在高渗透性自角砾岩带中，有少量斜发沸石、蒙脱石、次生钾长石、蛋白石-CT和胶状二氧化硅。残余玻璃与蚀变矿物的比例是可变的，主要取决于主岩的质地（渗透率）。研究的流纹岩覆盖在内乌肯群的上白垩纪沉积物上，并被莫尔喷发旋回和第四纪沉积物的第三纪玄武岩所覆盖。在地球化学上，它们与下至中中新世 Cordon del Burrero 火山复合体的流纹岩具有相似性。