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
Ignimbrite is a volcanic rock consisting mainly of pumice fragments, formed by the consolidation of material deposited by pyroclastic flows
Discoverer
Unknown
Patrick Marshall
Etymology
From Pelos or clay in Greek
From Latin ignis fire + imber, imbr- shower of rain, storm cloud + -ite
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, Opaque Rock
Texture
Foliated
Aphanitic
Color
Dark Greenish - Grey, Green, Light Green, Light Greenish Grey
Beige, Black, Brown, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Banded
Dull, Vesicular and Foilated
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone
As Building Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate
Building houses or walls, Construction Aggregate
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Commemorative Tablets, Creating Artwork
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Metamorphic rock
Pyroclastic rock
Features
Easily splits into thin plates, It is One of the Oldest, Strongest and Hardest Rock
Always found as volcanic pipes over deep continental crust
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.
Ignimbrites are formed from very poorly sorted mixture of volcanic ash or tuff and pumice lapilli, commonly with scattered lithic fragments.
Mineral Content
Albite, Chlorite, Quartz
Apatite, Biotite, Calcite, Chlorite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz
Compound Content
Aluminium Oxide, CaO, MgO
Ca, NaCl
Types of Metamorphism
-
Burial Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Porosity
Highly Porous
Highly Porous
Luster
Earthy
Vitreous to Dull
Specific Gravity
3.4-3.7
2.73
Transparency
Opaque
Opaque
Density
0-300 g/cm3
1-1.8 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
-
Afghanistan, Armenia, Azerbaijan, Burma, Cambodia, China, India, Indonesia, Iran, Japan, Malaysia, Mongolia, Nepal, North Korea, Pakistan, Saudi Arabia, Syria, Taiwan, Thailand, Turkey, Vietnam, Yemen
Africa
Western Africa
Cameroon, Cape Verde, Chad, Djibouti, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Tanzania, Uganda
Europe
United Kingdom
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
Others
-
Antarctica, Hawaii Islands
Deposits in Western Continents
North America
-
Canada, Costa Rica, Panama, USA
South America
Brazil, Colombia, Ecuador
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
Central Australia, Western Australia