Formation of Coquina and Tephrite

Coquina

Tephrite

Add ⊕

1 Formation

1.1 Formation

Coquina is a sedimentary rock which is formed when billions of small clam-like seashell, called Coquina, or cockleshell are die and hence are deposited, buried and turns into a rock when pressure is applied.

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.

1.2 Composition

1.2.1 Mineral Content

Apatite, Augite, Bronzite, Calcite, Chert, Chlorite, Clay Minerals, Epidote, Feldspar, Garnet, Micas, Muscovite or Illite

Alkali feldspar, Nepheline, Plagioclase, Pyroxene

1.2.2 Compound Content

CaO, Carbon Dioxide, Iron(III) Oxide, MgO

CaO, Carbon Dioxide, MgO, Silicon Dioxide

1.3 Transformation

1.3.1 Metamorphism

✔ ✘

1.3.2 Types of Metamorphism

Not Applicable

Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

1.3.3 Weathering

✔ ✘

1.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

1.3.5 Erosion

✔ ✘

1.3.6 Types of Erosion

Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion

Coquina and Tephrite Formation

Formation of rocks is a long process and hence, Coquina and Tephrite formation sounds very interesting. According to the formation, all rocks are divided into :Igneous Rocks, Fossil Rocks and Metamorphic Rocks. Igneous rocks form by crystallization of magma or lava. The magma is made up of various components of pre-existing rocks which have been subjected to melting either at subduction zones or within the Earth's mantle. Igneous rocks are generally seen at mid ocean ridges or in intra-plate hotspots. Sedimentary rocks are formed when sediments accumulate gradually. As the sediments are buried they get compacted as more and more material is deposited on top. Eventually the sediments become so dense that they form a rock. Metamorphic rocks are rocks which once existed as igneous or sedimentary rocks but have been subjected to varying degrees of pressure and heat within the Earth's crust. Get to know all about formation of Coquina and Tephrite, composition of Coquina and Tephrite and their transformation.