Definition
Marl is an unconsolidated sedimentary rock consisting of clay and lime
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Discoverer
William Smith
Van Tooren
Etymology
From Old French marle, from Late Latin marglia
From Greek tephra, ashes from Indo-European base, to burn
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Earthy
Aphanitic to Porphyritic
Color
Beige, Brown, Green, Grey, White
Black, Brown, Green, Grey, White
Durability
Durable
Durable
Appearance
Rough and Dull
Vesicular
Interior Uses
Decorative Aggregates, Floor Tiles
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, Roof Tiles
As Building Stone, As Facing Stone, 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
Landscaping
Antiquity Uses
Artifacts, Jewellery, Sculpture, Small Figurines
Artifacts, Sculpture
Commercial Uses
Creating Artwork, Soil Conditioner
Production of Lime, Soil Conditioner
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
Igneous rock
Features
Generally rough to touch, Is one of the oldest rock, Splintery, Very fine grained rock
Host Rock for Lead
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.
Tephrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Mineral Content
Calcite, Clay, Dolomite, Gypsum, Micas, Pyrite, Quartz
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, Silicon Dioxide
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Types of Metamorphism
-
Cataclastic Metamorphism, Contact 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
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Grain Size
Very fine-grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Uneven
Streak
White
Bluish Black
Porosity
Highly Porous
Very Less Porous
Luster
Dull
Subvitreous to Dull
Cleavage
-
Crenulation and Pervasive
Specific Gravity
2.2-2.8
2.86
Transparency
Opaque
Opaque
Density
2.4-2.8 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
India, Pakistan, Russia
-
Africa
Ethiopia, Kenya, Morocco, South Africa
Namibia, Uganda
Europe
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Germany, Hungary, Italy, Portugal, Spain
Deposits in Western Continents
South America
Colombia, Ecuador, Peru
-
Deposits in Oceania Continent
Australia
New South Wales, Victoria, Western Australia
New Zealand, Western Australia