1 Formation
1.1 Formation
Gneiss is a high grade metamorphic rock i.e. it has been subjected to higher temperatures and pressures than schist. It is formed by the metamorphosis of Gneiss forms from volcanic rock, shale or granitie.
Tuff is formed when large masses of ash and sand which are mixed with hot gases are ejected by a volcano and avalanche rapidly down its slopes.
1.2 Composition
1.2.1 Mineral Content
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Calcite, Chlorite
1.2.2 Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Hydrogen Sulfide, Sulfur Dioxide
1.3 Transformation
1.3.1 Metamorphism
1.3.2 Types of Metamorphism
Impact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
1.3.3 Weathering
1.3.4 Types of Weathering
Biological Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
1.3.5 Erosion
1.3.6 Types of Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion