Definition
Marl is an unconsolidated sedimentary rock consisting of clay and lime
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
History
Origin
-
-
Discoverer
William Smith
Unknown
Etymology
From Old French marle, from Late Latin marglia
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
Family
Group
-
-
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Earthy
Clastic or Non-Clastic
Color
Beige, Brown, Green, Grey, White
Grey, White, Yellow
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Rough and Dull
Soft
Architecture
Interior Uses
Decorative Aggregates, Floor Tiles
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, Roof Tiles
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Powder
Industry
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
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
Medical Industry
-
-
Antiquity Uses
Artifacts, Jewellery, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Creating Artwork, Soil Conditioner
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
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
Chalk Marl and Marl
Features
Generally rough to touch, Is one of the oldest rock, Splintery, Very fine grained rock
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Present
Present
Formation
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.
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
Composition
Mineral Content
Calcite, Clay, Dolomite, Gypsum, Micas, Pyrite, Quartz
Calcite, Clay, Clay Minerals, Quartz, Sand
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, Silicon Dioxide
Ca, NaCl, CaO
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Physical Properties
Hardness
2-31
1
7
👆🏻
Grain Size
Very fine-grained
Very fine-grained
Fracture
Conchoidal
-
Streak
White
White
Porosity
Highly Porous
Highly Porous
Luster
Dull
Dull
Compressive Strength
30.00 N/mm25.00 N/mm2
0.15
450
👆🏻
Cleavage
-
-
Toughness
2.6
1
Specific Gravity
2.2-2.82.3-2.4
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.4-2.8 g/cm32.49-2.50 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.80 kJ/Kg K0.90 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
India, Pakistan, Russia
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
Africa
Ethiopia, Kenya, Morocco, South Africa
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
Europe
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
England, France, Germany, Spain, United Kingdom
Others
-
-
Deposits in Western Continents
North America
USA
Canada, USA
South America
Colombia, Ecuador, Peru
Colombia
Deposits in Oceania Continent
Australia
New South Wales, Victoria, Western Australia
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula