Definition
Banded iron formation are distinctive units of sedimentary rock that are almost always of Precambrian age
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Origin
Western Australia, Minnesota
USA
Discoverer
Johann Gottlob Lehmann
Unknown
Etymology
From its formation process
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Banded, Trellis
Quench
Color
Red, Reddish Brown
Black, Brown, Green, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Layered, Banded, Veined and Shiny
Dull and Soft
Interior Uses
Decorative Aggregates, Homes
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
Paving Stone, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing, Whetstones
Curbing
Construction Industry
As Dimension Stone, Used for flooring, stair treads, borders and window sills.
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Antiquity Uses
Artifacts
Artifacts, Monuments
Commercial Uses
As a touchstone, Cemetery Markers, Creating Artwork
Creating Artwork, Gemstone
Types
Algoma-type , Lake Superior-type, Superior-type and Taconite
Cataclastic rock
Features
Is one of the oldest rock
Host Rock for Lead
Archaeological Significance
Formation
The banded iron layers are formed in sea water when oxygen is released by photosynthetic cyano-bacteria. The oxygen then combines with dissolved iron in ocean to form insoluble iron oxides, which precipitated out, forming a thin layer of banded iron formation on ocean floor.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Hematite, Magnetite, Quartz
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Compound Content
Fe, Iron(III) Oxide, Silicon Dioxide
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Chemical Weathering
-
Types of Erosion
Coastal Erosion, Wind Erosion
-
Grain Size
Large and Coarse Grained
Very fine-grained
Fracture
Uneven, Splintery or Conchoidal
Uneven
Streak
White
Light to dark brown
Porosity
Highly Porous
Less Porous
Specific Gravity
5.0-5.3
2.46-2.86
Transparency
Translucent to Opaque
Transparent to Translucent
Density
-9999 g/cm3
2.7-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Iraq, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
South Korea
Africa
Kenya, Morocco, South Africa, Tanzania
Western Africa
Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Great Britain, Switzerland
Others
Greenland, Mid-Atlantic Ridge
-
Deposits in Western Continents
North America
Canada, Mexico, USA
-
South America
Bolivia, Brazil
-
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
Central Australia, Western Australia
Banded iron formation vs Pseudotachylite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Banded iron formation vs Pseudotachylite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Banded iron formation and Properties of Pseudotachylite. Learn more about Banded iron formation vs Pseudotachylite in the next section. The interior uses of Banded iron formation include Decorative aggregates and Homes whereas the interior uses of Pseudotachylite include Decorative aggregates, Entryways and Interior decoration. Due to some exceptional properties of Banded iron formation and Pseudotachylite, they have various applications in construction industry. The uses of Banded iron formation in construction industry include As dimension stone, Used for flooring, stair treads, borders and window sills. and that of Pseudotachylite include As dimension stone, Cement manufacture, For road aggregate, Making natural cement.
More about Banded iron formation and Pseudotachylite
Here you can know more about Banded iron formation and Pseudotachylite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Banded iron formation and Pseudotachylite consists of mineral content and compound content. The mineral content of Banded iron formation includes Hematite, Magnetite, Quartz and mineral content of Pseudotachylite includes Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides. You can also check out the list of all Sedimentary Rocks. When we have to compare Banded iron formation vs Pseudotachylite, the texture, color and appearance plays an important role in determining the type of rock. Banded iron formation is available in red, reddish brown colors whereas, Pseudotachylite is available in black, brown, green, grey, pink, white colors. Appearance of Banded iron formation is Layered, Banded, Veined and Shiny and that of Pseudotachylite is Dull and Soft. Properties of rock is another aspect for Banded iron formation vs Pseudotachylite. The hardness of Banded iron formation is 5.5-6 and that of Pseudotachylite is 7. The types of Banded iron formation are Algoma-type , Lake Superior-type, Superior-type and Taconite whereas types of Pseudotachylite are Cataclastic rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Banded iron formation is white while that of Pseudotachylite is light to dark brown. The specific heat capacity of Banded iron formation is 3.20 kJ/Kg K and that of Pseudotachylite is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Banded iron formation is heat resistant, impact resistant, pressure resistant, wear resistant whereas Pseudotachylite is heat resistant.