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The geology of Pakistan encompasses the varied landscapes that make up the land constituting modern-day Pakistan, which are a blend of its geological history, and its climate over the past few million years. The Geological Survey of Pakistan is the premier agency responsible for studying the country's geology. [1]
It is presently being extracted from Siwalik rocks found near Villages of Jalalpur Sharif and Dina in Jhelum District. Workable deposits also occur in Attock. Sandy terrain of the Pabby Hills near village Tainpur. Dina, Jhelum District have been reported to be the best places where economic deposits of bentonite are found. [2] Mansehra: Calcite
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith ) is subjected to temperatures greater than 150 to 200 °C (300 to 400 °F) and, often, elevated pressure of 100 megapascals (1,000 bar ) or more, causing profound physical or chemical changes.
Marble is a metamorphic rock consisting of carbonate minerals (most commonly calcite (CaCO 3) or dolomite (CaMg(CO 3) 2) that have recrystallized under the influence of heat and pressure. [1] It has a crystalline texture, and is typically not foliated ( layered ), although there are exceptions.
Lapis lazuli is found in limestone in the Kokcha River valley of Badakhshan province in north-eastern Afghanistan, where the Sar-i Sang mine deposits have been worked for more than 6,000 years. [20] Afghanistan was the source of lapis for the ancient Persian, Egyptian and Mesopotamian civilizations, as well as the later Greeks and Romans.
It occurs in high temperature regional metamorphic rocks and in the skarns within contact aureoles around igneous intrusions. It also occurs in andesite volcanic rocks and altered ultramafic rocks. [3] Pargasite is the main water-storage site in the uppermost mantle; however, it becomes unstable at depths greater than 90 km (56 mi).
The metamorphic facies is not usually considered when classifying metamorphic rock based on protolith, mineral mode, or texture. However, a few metamorphic facies produce rock of such distinctive character that the facies name is used for the rock when more precise classification is not possible.
Schist (/ ˈ ʃ ɪ s t / SHIST) is a medium-grained metamorphic rock showing pronounced schistosity (named for the rock). This means that the rock is composed of mineral grains easily seen with a low-power hand lens , oriented in such a way that the rock is easily split into thin flakes or plates.