Definition
Ignimbrite is a volcanic rock consisting mainly of pumice fragments, formed by the consolidation of material deposited by pyroclastic flows
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
Discoverer
Patrick Marshall
Unknown
Etymology
From Latin ignis fire + imber, imbr- shower of rain, storm cloud + -ite
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic
Clastic or Non-Clastic
Color
Beige, Black, Brown, Grey, Pink, White
Grey, White, Yellow
Durability
Durable
Durable
Appearance
Dull, Vesicular and Foilated
Soft
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Powder
Construction Industry
Building houses or walls, Construction Aggregate
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, raw material for manufacture of quicklime and slaked lime, Source of calcium
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Alumina Refineries, Creating Artwork, Drawing on blackboards, Gymnasts, athletes and mountain climbers use for grip, In aquifers, Paper Industry, Production of Lime, Raw material for manufacture of quicklime, slaked lime, Soil Conditioner, Whiting, Whiting material in toothpaste, paint and paper
Types
Pyroclastic rock
Chalk Marl and Marl
Features
Always found as volcanic pipes over deep continental crust
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
Archaeological Significance
Formation
Ignimbrites are formed from very poorly sorted mixture of volcanic ash or tuff and pumice lapilli, commonly with scattered lithic fragments.
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
Mineral Content
Apatite, Biotite, Calcite, Chlorite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz
Calcite, Clay, Clay Minerals, Quartz, Sand
Compound Content
Ca, NaCl
Ca, NaCl, CaO
Types of Metamorphism
Burial Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
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Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Grain Size
Fine Grained
Very fine-grained
Porosity
Highly Porous
Highly Porous
Luster
Vitreous to Dull
Dull
Specific Gravity
2.73
2.3-2.4
Transparency
Opaque
Opaque
Density
1-1.8 g/cm3
2.49-2.50 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat 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
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
Africa
Cameroon, Cape Verde, Chad, Djibouti, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Tanzania, Uganda
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
Europe
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
England, France, Germany, Spain, United Kingdom
Others
Antarctica, Hawaii Islands
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Deposits in Western Continents
North America
Canada, Costa Rica, Panama, USA
Canada, USA
South America
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador
Colombia
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula
All about Ignimbrite and Chalk Properties
Know all about Ignimbrite and Chalk properties here. All properties of rocks are important as they define the type of rock and its application. Ignimbrite belongs to Igneous Rocks while Chalk belongs to Sedimentary Rocks.Texture of Ignimbrite is Aphanitic whereas that of Chalk is Clastic or Non-Clastic. Ignimbrite appears Dull, Vesicular and Foilated and Chalk appears Soft. The luster of Ignimbrite is vitreous to dull while that of Chalk is dull. Ignimbrite is available in beige, black, brown, grey, pink, white colors whereas Chalk is available in grey, white, yellow colors. The commercial uses of Ignimbrite are cemetery markers, commemorative tablets, creating artwork and that of Chalk are alumina refineries, creating artwork, drawing on blackboards, gymnasts, athletes and mountain climbers use for grip, in aquifers, paper industry, production of lime, raw material for manufacture of quicklime, slaked lime, soil conditioner, whiting, whiting material in toothpaste, paint and paper.