Formation of Chalk and Chert

Chalk

Chert

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1 Formation

1.1 Formation

Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.

Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.

1.2 Composition

1.2.1 Mineral Content

Calcite, Clay, Clay Minerals, Quartz, Sand

Quartz, Silicon

1.2.2 Compound Content

Ca, NaCl, CaO

Silicon Dioxide

1.3 Transformation

1.3.1 Metamorphism

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1.3.2 Types of Metamorphism

Not Applicable

1.3.3 Weathering

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1.3.4 Types of Weathering

Biological Weathering, Chemical Weathering

Not Applicable

1.3.5 Erosion

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1.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Water Erosion

Chemical Erosion

Chalk and Chert Formation

Formation of rocks is a long process and hence, Chalk and Chert 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 Chalk and Chert, composition of Chalk and Chert and their transformation.