Gneiss is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. This rock is formed under pressures anywhere from 2 to 15 kbar, sometimes even more, and temperatures over 300 °C (572 °F). Gneiss nearly always shows a banded texture characterized by alternating darker and lighter colored bands and without a distinct cleavage.
Migmatite is a composite rock found in medium and high-grade metamorphic environments, commonly within Precambrian cratonic blocks. It consists of two or more constituents often layered repetitively: one layer is an older metamorphic rock that was reconstituted subsequently by partial melting ("neosome"), while the alternate layer has a pegmatitic, aplitic, granitic or generally plutonic appearance ("paleosome"). Commonly, migmatites occur below deformed metamorphic rocks that represent the base of eroded mountain chains.
Buan County is a county in Jeonbuk State, South Korea. It is bounded by the city of Jeongeup on the east, the county of Gochang on the south, the city of Gimje on the north, and Yellow Sea on the west. Buan is divided into 1 eup, 12 myeon, and 510 ri. Buan had a 2001 estimated population of 74,716 people and a 2018 population of 54,441 people with an area of 493.35 km2. Famous people from Buan include Joseon Dynasty kisaeng and poet, Yi Mae-chang. Like many rural areas in southern Korea, it has seen shrinking population with many younger people moving north to larger cities such as Seoul. This county should not be confused with Muan, the new capital of South Jeolla Province.
Greenstone belts are zones of variably metamorphosed mafic to ultramafic volcanic sequences with associated sedimentary rocks that occur within Archaean and Proterozoic cratons between granite and gneiss bodies.
Lalbagh Botanical Garden or simply Lalbagh, is a botanical garden in Bangalore, India, with an over 200-year history. First planned and laid out during the dalavaiship of King Hyder Ali, the garden was later managed under numerous British Superintendents before Indian Independence. It was responsible for the introduction and propagation of numerous ornamental plants as well as those of economic value. It also served a social function as a park and recreational space, with a central glass house dating from 1890 which was used for flower shows. In modern times, it hosts two flower shows coinciding with the week of Republic Day and Independence Day. As an urban green space along with Cubbon Park, it is also home to numerous wild species of birds and other wildlife. The garden also has a lake adjoining a large rock on which a watchtower had been constructed during the reign of Kempegowda II.
The geology of India is diverse. Different regions of the Indian subcontinent contain rocks belonging to different geologic periods, dating as far back as the Eoarchean Era. Some of the rocks are very deformed and altered. Other deposits include recently deposited alluvium that has yet to undergo diagenesis. Mineral deposits of great variety are found in the subcontinent in huge quantities. Even India's fossil record is impressive in which stromatolites, invertebrates, vertebrates and plant fossils are included. India's geographical land area can be classified into the Deccan Traps, Gondwana and Vindhyan.
The Acasta Gneiss Complex, also called the Acasta Gneiss, is a body of felsic to ultramafic Archean basement rocks, gneisses, that form the northwestern edge of the Slave Craton in the Northwest Territories, Canada, about 300 km (190 mi) north of Yellowknife, Canada. This geologic complex consists largely of tonalitic and granodioritic gneisses and lesser amounts of mafic and ultramafic gneisses. It underlies and is largely concealed by thin, patchy cover of Quaternary glacial sediments over an area of about 13,000 km2 (5,000 sq mi). The Acasta Gneiss Complex contains fragments of the oldest known crust and record of more than a billion years of magmatism and metamorphism. The Acasta Gneiss Complex is exposed in a set of anticlinoriums within the foreland fold and thrust belt of the Paleoproterozoic Wopmay Orogen.
The Gascoyne Complex is a terrane of Proterozoic granite and metamorphic rock in the central-western part of Western Australia. The complex outcrops at the exposed western end of the Capricorn Orogen, a 1,000 km-long arcuate belt of folded, faulted and metamorphosed rocks between two Archean cratons; the Pilbara craton to the north and the Yilgarn craton to the south. The Gascoyne Complex is thought to record the collision of these two different Archean continental fragments during the Capricorn Orogeny at 1830–1780 Ma.
Bengaluru is situated in the southeast of the South Indian state of Karnataka. It is positioned at 12.97° N 77.56° E and covers an area of 2,190 square kilometres (850 sq mi). A landlocked city, Bengaluru is located in the heart of the Mysore Plateau at an average elevation of 920 metres (3,020 ft). Bangalore district borders with Kolar and Chikkaballapur in the northeast, Tumkur in the northwest, and Mandya and Ramanagaram in the southeast.
The Kaapvaal Craton, along with the Pilbara Craton of Western Australia, are the only remaining areas of pristine 3.6–2.5 Ga crust on Earth. Similarities of rock records from both these cratons, especially of the overlying late Archean sequences, suggest that they were once part of the Vaalbara supercontinent.
Leucogranite is a light-colored, granitic, igneous rock containing almost no dark minerals.
Sargur, is a small town located about 80 km from the town of Chamarajanagar And a Taluk of Mysore district of Karnataka, India. H D Kote (Heggadadevanakote) is about 12 km north of Sargur. It is 55 km from the city of Mysore. Bangalore International Airport is 200 km away. To be more elaborate, Sargur is 33.8 km from Nanjangud town (Karnataka), 35.1 km from Gundlupet town (Karnataka), 137.8 km from Udagamandalam town (Ooty) Valley and 38.8 km from Hunsur town (Karnataka).
Bugle Rock is a massive rock in the Basavanagudi area of South Bangalore, in the state of Karnataka. It is an abrupt rise above the ground of peninsular gneiss as the main rock formation and with an assessed age of about 3,000 million years. Bugle Rock has generated wide interest among the scientific community.
Natural Arch, Tirumala hills, a notified National Geo-heritage Monument, is a distinctive geological feature 1 km (0.6 mi) north of the Tirumala hills temple, near the Chakra Teertham in Tirupati district in the state of Andhra Pradesh, India. The arch is also called Silathoranam (శిలాతోరణం) in the local language. The arch measures 8 m (26.2 ft) in width and 3 m (9.8 ft) in height, and is naturally formed in the quartzites of Cuddapah Supergroup of Middle to Upper Proterozoic due to natural erosive forces.
Tirupati Eparchaean Unconformity, a notified National Geo-heritage Monument is a major discontinuity of stratigraphic significance that represents a period of remarkable serenity in the geological history of the Earth i.e. sudden changes and discontinuity in the rock layers in Earth's crust. It is seen at the steep natural slopes, road scars and ravines in the Tirupati – Tirumala Ghat road in Tirupati district of Andhra Pradesh, India.
The Lewisian complex or Lewisian gneiss is a suite of Precambrian metamorphic rocks that outcrop in the northwestern part of Scotland, forming part of the Hebridean Terrane and the North Atlantic Craton. These rocks are of Archaean and Paleoproterozoic age, ranging from 3.0–1.7 billion years (Ga). They form the basement on which the Stoer Group, Wester Ross Supergroup and probably the Loch Ness Supergroup sediments were deposited. The Lewisian consists mainly of granitic gneisses with a minor amount of supracrustal rocks. Rocks of the Lewisian complex were caught up in the Caledonian orogeny, appearing in the hanging walls of many of the thrust faults formed during the late stages of this tectonic event.
The Aravalli Mountain Range is a northeast-southwest trending orogenic belt in the northwest part of India and is part of the Indian Shield that was formed from a series of cratonic collisions. The Aravalli Mountains consist of the Aravalli and Delhi fold belts, and are collectively known as the Aravalli-Delhi orogenic belt. The whole mountain range is about 700 km long. Unlike the much younger Himalayan section nearby, the Aravalli Mountains are believed much older and can be traced back to the Proterozoic Eon. They are arguably the oldest geological feature on Earth. The collision between the Bundelkhand craton and the Marwar craton is believed to be the primary mechanism for the development of the mountain range.
The Baltimore Gneiss is a Precambrian geological formation in the Piedmont region of Maryland, Pennsylvania, and Delaware.
The Siilinjärvi carbonatite complex is located in central Finland close to the city of Kuopio. It is named after the nearby town of Siilinjärvi, located approximately 5 km west of the southern extension of the complex. Siilinjärvi is the second largest carbonatite complex in Finland after the Sokli formation, and one of the oldest carbonatites on Earth at 2610±4 Ma. The carbonatite complex consists of a roughly 16 km long steeply dipping lenticular body surrounded by granite gneiss. The maximum width of the body is 1.5 km and the surface area is 14.7 km2. The complex was discovered in 1950 by the Geological Survey of Finland with help of local mineral collectors. The exploration drilling began in 1958 by Lohjan Kalkkitehdas Oy. Typpi Oy continued drilling between years 1964 and 1967, and Apatiitti Oy drilled from 1967 to 1968. After the drillings, the laboratory and pilot plant work were made. The mine was opened by Kemira Oyj in 1979 as an open pit. The operation was sold to Yara in 2007.
The Dharwar Craton is an Archean continental crust craton formed between 3.6-2.5 billion years ago (Ga), which is located in southern India and considered the oldest part of the Indian peninsula.
