THOLEIITIC BASALT Meaning and
Definition
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Tholeiitic basalt refers to a type of volcanic rock that occurs as a result of volcanic activity and belongs to the basaltic composition group. It is primarily composed of plagioclase feldspar, augite (a type of pyroxene mineral), and magnetite. Tholeiitic basalt is typically dark gray to black in color and exhibits a fine-grained texture.
This type of basalt is particularly characterized by its chemical composition, which is low in alkali elements and rich in iron and magnesium. Tholeiitic basalt forms through the partial melting of the Earth's mantle, and it typically erupts at mid-ocean ridges and oceanic islands. It is common in areas such as the Atlantic Ocean and the Hawaiian Islands.
In terms of physical and chemical properties, tholeiitic basalt is known to have relatively low viscosity when molten, which allows it to flow easily and often form extensive lava flows. It usually has a relatively low silica content and a high magnesium content compared to other types of basalt.
Tholeiitic basalt is an important rock type in Earth's geology and has been extensively studied to gain insights into the composition and processes occurring in the Earth's mantle. It also holds economic significance, as it is used as a construction material, aggregate, and as a source of various metals like iron and magnesium.
Etymology of THOLEIITIC BASALT
The word "tholeiitic" originates from the Greek word "tholei", meaning "melting slowly". "Tholeiitic" is a term used in geology to describe a specific type of basaltic rock, characterized by its composition and crystallization process.
