Writers : Miri,Rouhollah;Etemadi,Bigan
Refference : The 21th Symposium on Geoscience;Tehran
Publishing Year : 1381

Abstract :

Kaolin from the Rokh Sefid deposit, located about 15-km Northwest of Gonabad (Khorasan province), has been analyzed for its mineralogical and chemical composition. Quartz, kaolinite, montmorillonite, dickite and alunite are the dominant minerals, with hematite as accessory minerals. Chemical data show that the kaolin is composed mainly of SiO2 and AL2O3 with the other oxides being present in trace amounts. The depletion in Fe, Mn, Mg, Ca, Na, and K not only shows the extent of the kaolinization, but also gives Rokh Sefid deposit its almost white color. Chemical results show that the parent rock in Rokh Sefid deposit is a K enrich rhyolite-rhyodacite.This rock altred influence hydrothermal fluid.The chondrite-normalized rare earth element (REE) patterns show enrichment in the light REEs, with a positive Sm anomaly. The parent-normalized rare earth element (REE) patterns show depletion in all REE (except Sm) especially HREE during the altration. Generaly REE, trace elements and major elements patterns show evidence of intense alteration and processes related to kaolinization.

Subject List : Kaolin