Definition
Marl is an unconsolidated sedimentary rock consisting of clay and lime
Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance
Discoverer
William Smith
Unknown
Etymology
From Old French marle, from Late Latin marglia
From Latin varius, speckled, variegated
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Opaque Rock
Texture
Earthy
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Beige, Brown, Green, Grey, White
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Appearance
Rough and Dull
Dull and Soft
Interior Uses
Decorative Aggregates, Floor Tiles
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, Roof Tiles
Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Antiquity Uses
Artifacts, Jewellery, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
Commercial Uses
Creating Artwork, Soil Conditioner
Cemetery Markers, Creating Artwork
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
Metamorphic rock
Features
Generally rough to touch, Is one of the oldest rock, Splintery, Very fine grained rock
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
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.
Variolites are a group of dark green basic igneous rocks that exhibit pale colored spots on weathered surfaces that give them a pockmarked appearance.
Mineral Content
Calcite, Clay, Dolomite, Gypsum, Micas, Pyrite, Quartz
Olivine, Plagioclase, Pyroxene
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
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Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
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Grain Size
Very fine-grained
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Fracture
Conchoidal
Conchoidal
Streak
White
White to Grey
Porosity
Highly Porous
Less Porous
Specific Gravity
2.2-2.8
2.8-3
Transparency
Opaque
Opaque
Density
2.4-2.8 g/cm3
2.9-3.1 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Pakistan, Russia
India, Russia
Africa
Ethiopia, Kenya, Morocco, South Africa
South Africa
Europe
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Iceland
Deposits in Western Continents
North America
USA
Canada, USA
South America
Colombia, Ecuador, Peru
Brazil
Deposits in Oceania Continent
Australia
New South Wales, Victoria, Western Australia
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All about Marl and Variolite Properties
Know all about Marl and Variolite properties here. All properties of rocks are important as they define the type of rock and its application. Marl belongs to Sedimentary Rocks while Variolite belongs to Igneous Rocks.Texture of Marl is Earthy whereas that of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular. Marl appears Rough and Dull and Variolite appears Dull and Soft. The luster of Marl is dull while that of Variolite is . Marl is available in beige, brown, green, grey, white colors whereas Variolite is available in black, brown, light to dark grey colors. The commercial uses of Marl are creating artwork, soil conditioner and that of Variolite are cemetery markers, creating artwork.