Definition
Metapelite is an old and currently not widely used field geological term for a clay rich fine-grained clastic sediment or sedimentary rock, i.e. mud or a mudstone
Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs
Origin
-
Adak, Aleutian Islands
Discoverer
Unknown
Defant and Drummond
Etymology
From Pelos or clay in Greek
From Adak, Aleutian Islands
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Foliated
Porphyritic
Color
Dark Greenish - Grey, Green, Light Green, Light Greenish Grey
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Appearance
Banded
Dull and Soft
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, As Facing Stone
As Building Stone, As Facing Stone, Office Buildings
Other Architectural Uses
Curbing
Whetstones
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Antiquity Uses
Artifacts
Monuments, Sculpture, Small Figurines
Commercial Uses
Commemorative Tablets, Creating Artwork
Commemorative Tablets, Pottery, Used in aquariums
Types
Metamorphic rock
Intermediate volcanic rock
Features
Easily splits into thin plates, It is One of the Oldest, Strongest and Hardest Rock
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
Archaeological Significance
Formation
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Metapelite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Adakite rocks are formed when the hydrous fluids are released from minerals that break down in metamorphosed basalt, and rise into the mantle they initiate partial melting.
Mineral Content
Albite, Chlorite, Quartz
Olivine, Plagioclase, Pyroxene
Compound Content
Aluminium Oxide, CaO, MgO
Aluminium Oxide, MgO, Silicon Dioxide
Types of Metamorphism
-
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Sea Erosion, Water Erosion
Grain Size
Medium to Fine Coarse Grained
Fine to Medium Grained
Fracture
Fibrous
Conchoidal
Porosity
Highly Porous
Less Porous
Luster
Earthy
Grainy, Pearly and Vitreous
Specific Gravity
3.4-3.7
-9999
Transparency
Opaque
Opaque
Density
0-300 g/cm3
-9999 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Africa
Western Africa
Ethiopia, Somalia, South Africa
Europe
United Kingdom
Iceland
Deposits in Western Continents
North America
-
Canada, USA
South America
Brazil, Colombia, Ecuador
Brazil
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
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