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Mylonite and Boninite


Boninite and Mylonite


Definition

Definition
Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism  
Boninite is a mafic extrusive rock which is high in magnesium and silica content, formed in fore-arc environments, typically during the early stages of subduction  

History
  
  

Origin
New Zealand  
Japan  

Discoverer
Unknown  
Unknown  

Etymology
From Greek mulōn mill + -ite  
From its occurrence in the Izu-Bonin arc south of Japan  

Class
Metamorphic Rocks  
Igneous Rocks  

Sub-Class
Durable Rock, Medium Hardness Rock  
Durable Rock, Hard Rock  

Family
  
  

Group
-  
Volcanic  

Other Categories
Fine Grained Rock, Opaque Rock  
Fine Grained Rock, Opaque Rock  

Texture

Texture
Foliated  
Aphanitic to Porphyritic  

Color
Black to Grey  
Bluish - Grey, Brown, Green, Grey  

Maintenance
Less  
Less  

Durability
Durable  
Durable  

Water Resistant
Yes  
No  

Scratch Resistant
Yes  
Yes  

Stain Resistant
No  
Yes  

Wind Resistant
No  
Yes  

Acid Resistant
No  
No  

Appearance
Dull, Banded and Foilated  
Dull and Soft  

Uses

Architecture
  
  

Interior Uses
Decorative Aggregates, Interior Decoration  
Decorative Aggregates, Homes, Kitchens  

Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration  
Garden Decoration, Office Buildings  

Other Architectural Uses
Curbing  
-  

Industry
  
  

Construction Industry
for Road Aggregate, Landscaping, Roadstone  
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories  

Medical Industry
-  
-  

Antiquity Uses
Artifacts, Monuments  
Artifacts  

Other Uses
  
  

Commercial Uses
Creating Artwork, Gemstone, Jewelry  
An Oil and Gas Reservoir, Cemetery Markers, Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)  

Types

Types
Blastomylonites, Ultramylonites and Phyllonites  
Basalt  

Features
Surfaces are often shiny  
Available in Lots of Colors and Patterns, High Mg content, Is one of the oldest rock  

Archaeological Significance
  
  

Monuments
-  
-  

Famous Monuments
-  
-  

Sculpture
-  
-  

Famous Sculptures
-  
-  

Pictographs
-  
-  

Petroglyphs
-  
-  

Figurines
-  
-  

Fossils
Absent  
Absent  

Formation

Formation
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.   
Boninite is a type of Igneous rock which is formed through the cooling and solidification of lava or existing rocks.  

Composition
  
  

Mineral Content
Porphyroblasts  
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite  

Compound Content
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide  
Silicon Dioxide  

Transformation
  
  

Metamorphism
No  
Yes  

Types of Metamorphism
-  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism  

Weathering
Yes  
Yes  

Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering  
Biological Weathering  

Erosion
Yes  
Yes  

Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion  
Chemical Erosion, Coastal Erosion, Wind Erosion  

Properties

Physical Properties
  
  

Hardness
3-4  
7  

Grain Size
Fine Grained  
Fine Grained  

Fracture
Conchoidal  
Uneven  

Streak
White  
White  

Porosity
Highly Porous  
Less Porous  

Luster
Shiny  
Vitreous  

Compressive Strength
1.28 N/mm2  
99+
150.00 N/mm2  
22

Cleavage
Conchoidal  
-  

Toughness
-  
1.1  

Specific Gravity
2.97-3.05  
2.5-2.8  

Transparency
Opaque  
Opaque  

Density
2.6-4.8 g/cm3  
-9999 g/cm3  

Thermal Properties
  
  

Specific Heat Capacity
1.50 kJ/Kg K  
3
0.84 kJ/Kg K  
15

Resistance
Heat Resistant, Impact Resistant, Pressure Resistant  
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant  

Reserves

Deposits in Eastern Continents
  
  

Asia
China, India, Indonesia, Saudi Arabia, South Korea  
-  

Africa
Eritrea, Ethiopia, Ghana, South Africa, Western Africa  
South Africa  

Europe
England, Finland, France, Germany, Great Britain, Greece, United Kingdom  
England, Finland, United Kingdom  

Others
-  
Antarctica, Greenland  

Deposits in Western Continents
  
  

North America
USA  
USA  

South America
-  
Colombia, Uruguay  

Deposits in Oceania Continent
  
  

Australia
Central Australia, Western Australia  
New Zealand, Western Australia  

Summary >>
<< Reserves

All about Mylonite and Boninite Properties

Know all about Mylonite and Boninite properties here. All properties of rocks are important as they define the type of rock and its application. Mylonite belongs to Metamorphic Rocks while Boninite belongs to Igneous Rocks.Texture of Mylonite is Foliated whereas that of Boninite is Aphanitic to Porphyritic. Mylonite appears Dull, Banded and Foilated and Boninite appears Dull and Soft. The luster of Mylonite is shiny while that of Boninite is vitreous. Mylonite is available in black to grey colors whereas Boninite is available in bluish - grey, brown, green, grey colors. The commercial uses of Mylonite are creating artwork, gemstone, jewelry and that of Boninite are an oil and gas reservoir, cemetery markers, creating artwork, soil conditioner, source of magnesia (mgo).

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