POIKILITIC Meaning and
Definition
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Poikilitic is an adjective that refers to a textural term commonly used in petrology to describe a specific type of igneous rock texture. It is derived from the Greek word "poikilos," meaning variegated or motley. Poikilitic rocks possess a unique texture in which large mineral crystals, known as phenocrysts, are scattered or enclosed within a fine-grained or glassy groundmass.
The defining characteristic of poikilitic textures is the presence of these phenocrysts embedded within the groundmass. These phenocrysts can be made up of various minerals, such as feldspar, quartz, pyroxene, amphibole, or olivine. The groundmass, on the other hand, consists of smaller mineral crystals or sometimes even glassy material. The distribution of phenocrysts within the groundmass is typically random or irregular, giving the rock a speckled or patchwork appearance when observed under a microscope or in hand sample.
Poikilitic textures commonly form in rapidly cooling igneous rocks, such as volcanic or intrusive magmas. The presence of phenocrysts indicates that the rock experienced a two-stage cooling process, where larger crystals formed earlier, followed by the rapid solidification of the remaining melt. This unique texture can provide valuable information about the rock's formation history and the conditions under which it was formed.
In summary, poikilitic describes a specific igneous rock texture characterized by the presence of large mineral crystals (phenocrysts) dispersed within a fine-grained or glassy groundmass, forming a variegated or motley appearance.
Common Misspellings for POIKILITIC
Etymology of POIKILITIC
The word "poikilitic" comes from the Greek word "poikilos" (ποικίλος), meaning "variegated" or "multicolored". In geology, "poikilitic" is used to describe a type of igneous rock that contains various embedded minerals, giving it a speckled or mottled appearance. The term was first coined in the 1900s to describe this specific geological characteristic.
Similar spelling word for POIKILITIC
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