Clay minerals in hydrothermally altered volcanic rocks, Eastern Pontides, Turkey

Celik M., KARAKAYA N., Temel A.

CLAYS AND CLAY MINERALS, vol.47, no.6, pp.708-717, 1999 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 47 Issue: 6
  • Publication Date: 1999
  • Doi Number: 10.1346/ccmn.1999.0470604
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.708-717
  • Keywords: bentonite, clay minerals, Eastern Pontides, hydrothermal alteration, illite, smectite, toseki, volcanogenic massive sulfide, ORE-DEPOSITS, MINERALIZATION, CHEMISTRY, SMECTITE, ILLITE
  • Hacettepe University Affiliated: Yes


Extensive hydrothermal alteration is observed around volcanogenic massive sulfide deposits. These deposits are related to Late Cretaceous volcanism in various parts of the Eastern Pontide province. Mineral assemblages resulting from alteration consist of mostly clay minerals and silica polymorphs, some sulfate minerals, and scarce zeolite minerals. The clay minerals are kaolinite, illite, and smectite. These minerals were examined using X-ray diffraction (XRD), scanning electron microscopy (SEM)energy dispersive spectrometry (EDS), X-ray fluorescence spectroscopy (XRF), and differential thermal analysis (DTA)-thermal gravimetry (TG) techniques. The illite and the toseki deposits are a result of hydrothermal alteration of dacitic-andesitic volcanites. Two groups of bentonite deposits occur; the first mainly formed by hydrothermal solution whereas the second group resulted from halmyrolysis.