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
Basaltic Trachyandesite is an extrusive igneous rock which is a type of Basalt rock and is formed by the rapid cooling of basaltic lava exposed at or very near the Earth's surface
History
Origin
New Zealand
-
Discoverer
Unknown
Unknown
Etymology
From Greek mulōn mill + -ite
From its mineral and compound content and its relation with Basalt and Andesite rock
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Foliated
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Black to Grey
Black, Brown, Light to Dark Grey
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull, Banded and Foilated
Dull and Soft
Architecture
Interior Uses
Decorative Aggregates, Interior Decoration
Floor Tiles, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
As Building Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing, Whetstones
Industry
Construction Industry
for Road Aggregate, Landscaping, Roadstone
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments
Other Uses
Commercial Uses
Creating Artwork, Gemstone, Jewelry
An Oil and Gas Reservoir, Commemorative Tablets, Creating Artwork
Types
Blastomylonites, Ultramylonites and Phyllonites
Alkaline Basalt, Boninite, High Alumina Basalt, Mid Ocean Ridge Basalt (MORB), Tholeiitic Basalt, Basaltic trachyandesite, Mugearite and Shoshonite
Features
Surfaces are often shiny
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
Formation
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
Basaltic Trachandesite is a fine-grained, hard rock that forms when bits of lava shoot out of volcanoes.
Composition
Mineral Content
Porphyroblasts
Olivine, Plagioclase, Pyroxene
Compound Content
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
Contact Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
-
Physical Properties
Hardness
3-46
1
7
👆🏻
Grain Size
Fine Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Streak
White
White to Grey
Porosity
Highly Porous
Less Porous
Luster
Shiny
-
Compressive Strength
1.28 N/mm237.50 N/mm2
0.15
450
👆🏻
Cleavage
Conchoidal
-
Toughness
-
2.3
Specific Gravity
2.97-3.052.8-3
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.6-4.8 g/cm32.9-3.1 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
1.50 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Saudi Arabia, South Korea
India, Russia
Africa
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
South Africa
Europe
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
Iceland
Others
-
-
Deposits in Western Continents
North America
USA
Canada, USA
South America
-
Brazil
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
-