Mineralogy and chemistry of zeolites and associated minerals in Tertiary alkaline volcanics from the Eastern Pontides, NE Turkey

Abdioglu E.

NEUES JAHRBUCH FUR MINERALOGIE-ABHANDLUNGEN, vol.189, no.1, pp.35-47, 2012 (SCI-Expanded) identifier identifier identifier


Large cavity filling and vein-type zeolites and associated minerals from Tertiary alkaline volcanics in the Eastern Pontide, northeast Turkey, have been studied for their mineralogical, chemical and O-D isotope characteristics. X-ray powder diffraction, scanning electron microscopy and chemical analyses confirmed the presence of the natrolite, analcime, disordered thomsonite, laumontite, phillipsite and mesolite as zeolite minerals and apophyllite, calcite, aragonite and chlorite as associated phases. The first stage of secondary mineral assemblages (natrolite, analcime) in veins and cavities crystallized during final stages of lava cooling from aqueous solutions, which are mixture of seawater and meteoric water with magmatic water enriched in Na and K. Ca-rich zeolites followed the natrolite and analcime crystallization, and finally calcite and aragonite formed from the late fluids containing Ca, Na, K and (CO3)(2-) leached from underlying calcareous sedimentary rocks and host volcanics.