Mass Transfer Essay

Submitted By samrzv
Words: 325
Pages: 2

The low grade (0.07wt% Cu in average) Sonajil porphyry Cu deposit(PCD) is hosted within Eocene to Plio-Quaternary plutonic and volcanic rocks of the Urmieh – Dokhtar Volcanic Belt, NW Iran. The main Eocene dioritic body, which containsthe Cu mineralization, that is intruded into Early Eocene volcaniclastic rocks. Three main alteration stages:(i) comprising potassic (with major proportion of copper mineralization);(ii) later phyllic;(iii) and subsequent argillic alteration were studied in term of mass changes and element mobility. The graphical isocon methodwas used to illustratequantitative mass changes in the Sonajil PCD. Theresults of the analysisshow that Al2O3, TiO2, and MnO were relatively immobile during the hydrothermal evolution of the Sonajil PCD withthe average mass change factors of 1.04, 1.02, and 0.99 calculated for potassic, phyllic, and argillicalterationtypes, respectively.Therefore, it is possible that the hydrothermal evolution of the Sonajil PCDhas beenassociated mainly with minimal volume changes. In the potassic zone, K, Na, and Ba were enriched whereas Fe, Ca, and Mgwere depleted.This is consistent with the break-down of plagioclase and biotiteas well as alkali exchange reactions leading to the formation of microcline. Moreover, significant amount of Cu and S were added in the potassic alteration zone manifested bythe distribution of chalcopyrite and bornite. Withinthe phyllic alteration zone, SiO2 and some other trace elements were enriched whereas Na,…