AN EXAMPLE TO SEPIOLITE FORMATION IN VOLCANIC BELTS BY HYDROTHERMAL ALTERATION: KIBRISCIK (BOLU) SEPIOLITE OCCURRENCE

Indexed In

Volume 115 / 1993

Authors:

Taner IRKEÇ, Taner ÜNLÜ

Keywords:

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Abstract:

Geological, mineralogical and chemical properties of a sepiolite occurrence, located in the south of Kıbrıscık township of Bolu Province, north central Turkey, have been investigated in detail, and new mineralogical data have been obtained. Differing from the sedimentary sepiolite deposits, mostly associated with the carbonate/evaporite sequences, Kıbrıscık sepiolite occurs in the Köroğlu (Gallatian) Volcanic Belt and has formed by the hydrothermal alteration of the vitric tuff unit of Middle Miocene aged Deveören Volcanites. The mineral, which shows a similar XRD pattern to sepiolite, gives DTA and IR patterns with close resemblance to those of palygorskite, in addition to its chemical composition with rather high alumina content. There are indications of monoclinal symmetry, determined by XRD, and it is thought to be possible that the material represents a new mineral phase.