1. Mineralization controlled by Tectonics & structures Speaker Prof
Mineralization controlled by Tectonics & structures Speaker Prof. Mohamed Th .s. Heikal Geology Department , Faculty of Science, Tanta University

2. Contents Introduction Mineralization related to plate tectonics
Mineralization related to regional and minor structures
Examples
Summery

3. Introduction
Mining geologists have for many decades attempted to relate various types of mineralization to large scale crustal structures.
Nearly all hydrothermal deposits exhibit some degree of structural control on mineralization. 
Structures (fractures, faults or folds) which form prior to a mineralizing event are referred to as “pre-mineral”. 
Geologists are keenly interested in pre-mineral structures because these structures influence the localization of ore by hydrothermal fluids utilizing these pathways.

5. Mineralization related to plate tectonics
Plate convergence and spreading centers are among the important features which control the global location of mineral deposits.
Other important features to which mineralization appears to be related include hotspots,(mantle plumes), rifting and other extensional tectonics, and collision tectonics.

6. Mineralization related to plate tectonics
Intracratonic basins are accompanied by mineralization e.g. the late Proterozoic Central African Copper.
Ocean basins and rises
At some stage during this process an opening to the sea may initiate marine conditions.
Observations from theRed Sea region indicate that evaporite series of great thickness may form at this time. These evaporites contain halite as well as gypsum and therefore have a double economic importance.

7. Hydrothermal mineralization with the development of copper, zinc, silver and mercury has been reported from oceanic ridges in the Atlantic and Indian Oceans.
it was generated by sea water solutions circulating through the oceanic crust that related to black smokers .
black smokers have now been found on the Mid-Atlantic Ridge indicating that the hydrothermal processes which produce them probably operate along most active sea floor spreading centers.

8. Black smokers
Black smokers and associated minerals .

9. Subduction-related settings
Subdction zone and it’s association minerals

10. General figure show the associated minerals at different tectonic settings

11. Structures Controlling on Mineraliztion
Structures (fractures, faults or folds) which form prior to a mineralizing event are referred to as “pre-mineral”. 
Structures which form after a mineralizing event, and hence may be responsible for offset or removal of mineralized zones, are referred to as “post- mineral”. 
In some cases the formation of structures and mineralization appear to be nearly synchronous. 

12. Mineralization Related to Faulting
Fractures and fault zones provide excellent pathways for hydrothermal fluids to circulate through. 
Open-space filling has long been recognized as the primary method of vein formation.
The formation of breccia due to the grinding action of the rocks adjacent to the fault plane increases the ‘structural porosity’, .
Under certain conditions, breccia may itself provide the host for mineralization. 
Intersections of structural features often are better locations to prospect for mineralization

13. This figure show mineralization related to faults

14. Mineralization Related to folding
Within the geological record there is evidence of numerous ore deposits precipitated in or near geological fold belts.
This is due to the fact that folds can play different roles in transporting aqueous minerals in a hydrothermal system.
For a permeable fold, the focusing and mixing of different reactive fluids can take place within the fold.
Whereas for an impermeable fold, the existence of the fold can change and even determine the channels of pore-fluid in a hydrothermal system.

15. Mineralization related to Shear Zones
Low-grade basement rocks of Neoproterozoic age with well developed shear zones from Hawzien area of northern Ethiopia.
Geochemistry of surface and drill core samples indicate enrichment of zinc in shear zones with low concentrations of copper, lead, gold, arsenic and silver.
Zn-rich base metal mineralization with Pb-Cu-Fe (±Ag-As-Au) is related to D2 deformation through the shear zone.

16. Field photographs showing D1 & D2 in phyllite (A); in metavolcaniclastic rock (B); preshearing quartz dike/vein in phyllite (C); 2nd generation quartz veins during shearing in metavolcaniclastic (D); and 3rd generation quartz veins of post-shearing in metavolcaniclastic (E). Source Investigation of Mineralization Related to Detachment Faulting, Joshua Sargent Geological Sciences Department California State Polytechnic University, Pomona, CA

17. Examples of most common areas enriched with ore deposits in Egypt
One of the most common areas that enriched with minerals in Egypt is Wadi Allaqi area, which most of its mineralization related to major or large structures.
Wadi Allaqi located in the South Eastern desert of Egypt.

18. Geology of the Wadi Allaqi area
The Wadi Allaqi area is underlain by Neoproterozoic rocks, Cretaceous sandstones, and Mesozoic to Cenozoic volcanic and sub-volcanic rocks.
These rocks include a mafic–ultramafic ophiolitic assemblage, at least two volcano-sedimentary- plutonic island arc assemblages, and late- to post- tectonic granitic intrusions (Krṏoner et al., 1987; Greiling et al., 1994; Shackleton, 1994; Abdelsalam and Stern, 1996; Taylor et al., 1993; Berhe, 1990; Shackleton, 1994).

19. Structure geology of WadiAllaqi
field and remote-sensing studies suggest thatthe western part of the Allaqi suture developed through four phases of Neoproterozoic deformation (D1 through D4).
D1 and D2 are associated with early collisional stages between the Gerfterrane in the north with the Haya and GabgabaTerranes to the south.
whereas D3 and D4 represent deformation associated with the later stages of collision (Abdelsalam and Stern, 1996), characterized by development of tight to isoclinal, gently inclined folds, and reactivation of some of the thrust faults in the E–W imbricate thrust zones.

20. Structural map of Wadi Allaqi

21. Mineral deposits of WadiAllaqi
Several mineral deposits are associated with different rock units and structures in the study area.
Copper– nickel–platinum mineralization, podiform chromite, and gold–quartz veins are associated with ultramafic rocks.
Marble, gold-bearing quartz veins and alteration zones possibly associated with massive sulfides are associated with metavolcanics, and zones of radioactive mineralization are associated with leucocratic granitic rocks.

22. Landsat TM and SIR-C/X SAR images as well as field studies indicate that these mineral deposits are structurally controlled, as well as being associated spatially with the late granites, as the following:
Mineral deposits associated with D1, D2 (imbricate thrust belt)
Mineral deposits associated with D3 (WadiUngate shear zone)
Mineral deposits associated with D3, D4 (E–W fractures and late granites)
The following table show the deformation events and the mineraliztion that releated to them in Wadi Allaqi

24. Summary
Fractures and shear zones provide excellent pathways for hydrothermal fluids to circulate through from their sources to near surfaces.
Folds can play different roles in transporting aqueous minerals in a hydrothermal system.
Also the shear zones consider one of the most important areas lead to concentration and formation of certain economic minerals.
Besides the structural elements controlling much more mineralization, some plate tectonic environments play important roles to indicate mineralized zones.

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