THENARDITE MINERALIZATIONS OF CAYIRHAN SULFATE OCCURRENCES IN ANKARA, TURKEY: INVESTIGATION OF PARAGENESIS AND FORMATION MECHANISMS

10th International Multidisciplinary Scientific GeoConference - SGEM2010, www.sgem.org, SGEM2010 Conference Proceedings/ ISBN 10: 954-91818-1-2, June 20-26, 2010, Vol. 1, 603-610 pp

ABSTRACT

Preliminary investigation of mineralizations of Thenardite associated with sulfate
occurrences in Çayırhan – Beypazarı, Ankara is presented. Local geology consists of
Paleozoic metamorphite schists, Permo-triassic granitic rocks, Middle Jurassic – Upper
Cretaceous limestones and marls in flysch facies, Paleocene aged land sedimentaries
and marine Eocene units, Miocene to Pliocene aged lacustrine units, which sodium
sulfates are associated to. Thenardite, Glauberite and Mirabilite minerals have been
detected by XRD analysis. Thenardite formations have precipitated in small lakes
during Pliocene in middle Anatolia. Ten thenardite samples have been investigated for
Ca, Mg, Sr, K and Na elements in order to determine the geochemical properties of the
mineralization. Petrographical and geochemical analyses show varying cycles and
phases of mineral paragenesis, indicating sudden changes of evaporate precipitation
history.

Keywords: Thenardite, Sulfates, Evaporates, Paragenesis, Ankara