Usage of Textural, Structural & Mineralogical Evidences in Determination of Conditions of Gazestan Phosphat Ore Genesis
|Category||Economic geology & mineral exploration|
|Location||21th symposium on geosciences|
|Holding Date||21 May 2008|
Gazestan phosphate deposit is situated at 78km east of Bafgh, in the central Iran. The main rocks of this deposit consist of alternation of igneous (intrusive and extrusive) and volcano-sedimentary rocks, related to the Rizu series. The composition of igneous rocks varied from acidic to basic, but the acidic rocks hae very wide spread outcrops with extensive alteration such as silicification, feldspatization, sericitization, saussoritization and proplitization. The mineralization consists of apatite and magnetite with minor amounts of calcite and quartz. The mineralization could be seen in five forms:
1- Lenses and dyke-like bodies of magnetite ? apatite.
2- Coarse grained apatite - magnetite veins.
3- Veinlets of magnetite-apatite in form of stock work.
4- Disseminated apatite magnetite grains in feldespatic rocks.
5- Massive apatite veins.
6- Sulfide veinlets
These forms of mineralization differs each other from the point of structure, texture and pargenesis which could be related to the physico ? chemical composition of their formation.