Processes of Magma Movement and Ore Mineral Crystallization
Explore the movement of magma and magmatic fluids, including transportation methods like mechanical pressure, tectonic stress, gas movement, assimilation, and stoping. Learn about ore mineral crystallization through direct crystallization from magma and magmatic differentiation like partial fractionation and gravity settling. Discover how magmatic fluids immiscibility leads to the concentration of desirable elements in different types of melts like oxides, sulfides, and carbonates.
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
You are allowed to download the files provided on this website for personal or commercial use, subject to the condition that they are used lawfully. All files are the property of their respective owners.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author.
E N D
Presentation Transcript
Movement of magma and magmatic fluids Magma and magmatic fluids transported by the following ways acting singly or together: 1- mechanical pressure 2-tectonic stress or compression 3- movement of gases 4- magmatic assimilation 5- magmatic stoping
Modes of ore minerals crystallization : Concentration and Crystallization of the metallic minerals from magma and magmatic fluids by: 1- Direct crystallization from magma 2- Magmatic differentiation
2- Magmatic differentiation:- (a) Partial fractionation (b) Differentiation by gravity Settling of crystals in a magma chamber can concentrate minerals like :- Spinel Group of Minerals all relatively dense. spinel: MgAl2O4 Basaltic magmas contain about: 10% Fe , a few percent Ti and trace amounts of Cr, Mn, and V Under favorable circumstances these become concentrated in the spinel. Since the spinel crystals are dense, they can sink to the bottom of a slowly cooling magma body and make layers of ore Density of basaltic magma: 2500 kg/m3 Density of Cr spinel: 4800 kg/m3
(C) Magmatic fluids immiscibility Oil and water don t mix . As magmas cool, they can split into two liquids of different composition and density. One of these liquids is the silica-rich melt, It has the most volume and the other, typically much smaller in volume, can be rich in metal oxides, sulfides or carbonate. preferentially concentrated into the low-volume melt. Desirable element is
Types of Immiscible Melts Oxide melts can be rich in Fe (Fe2O3, hematite) and Ti (FeTiO3, ilmenite). Sulfide melts can be rich in Ni, Cu, and the platinum- group elements, in addition to iron sulfur (FeS, pyrrhotite). Carbonate melts can be rich in niobium, tantalum, rare earths, copper, thorium, and phosphorous .
