Definition
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
Marl is an unconsolidated sedimentary rock consisting of clay and lime
Discoverer
Unknown
William Smith
Etymology
From French, Latin lignum wood + -ite1
From Old French marle, from Late Latin marglia
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Amorphous, Glassy
Earthy
Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Beige, Brown, Green, Grey, White
Durability
Durable
Durable
Appearance
Veined or Pebbled
Rough and Dull
Interior Uses
-
Decorative Aggregates, Floor Tiles
Exterior Uses
-
As Building Stone, Roof Tiles
Other Architectural Uses
-
Curbing
Construction Industry
for Road Aggregate, Steel Production
Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Antiquity Uses
-
Artifacts, Jewellery, Sculpture, Small Figurines
Commercial Uses
Electricity Generation
Creating Artwork, Soil Conditioner
Types
Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite
Clay Marl ,Blue Marl, Red Marl, High Bank Marl, Shell Layer Marl, Under Shell Layer Marl, Sand Marl, Green Marl, Grey Marl and Clayey Marl
Features
Generally rough to touch, Helps in production of Heat and Electricity, Used as fossil fuel
Generally rough to touch, Is one of the oldest rock, Splintery, Very fine grained rock
Archaeological Significance
Formation
Coal formation takes place due to accumulation of plant debris in a swamp environment. The Coal formation process continues, as peat turns into lignite brown or black coal at increasing heat and pressure.
Marl forms when very fine-grained clay particles are deposited in water which settles at the bottom of water bodies and are compacted by overlying sediment; the water squeezes out and hence forming Marl rock.
Mineral Content
-
Calcite, Clay, Dolomite, Gypsum, Micas, Pyrite, Quartz
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, Silicon Dioxide
Types of Metamorphism
-
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Very fine-grained
Fracture
Conchoidal
Conchoidal
Porosity
Highly Porous
Highly Porous
Luster
Dull to Vitreous to Submetallic
Dull
Specific Gravity
1.1-1.4
2.2-2.8
Transparency
Opaque
Opaque
Density
800-801 g/cm3
2.4-2.8 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
India, Pakistan, Russia
Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Ethiopia, Kenya, Morocco, South Africa
Europe
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Deposits in Western Continents
North America
Canada, Mexico, USA
USA
South America
Brazil, Chile, Colombia, Venezuela
Colombia, Ecuador, Peru
Deposits in Oceania Continent
Australia
New South Wales, Queensland, Victoria
New South Wales, Victoria, Western Australia