Granite And Charnockite

Igneous charnockites are characterised by distinctively high abundances of K 2 O, TiO 2, P 2 O 5 and LIL elements and low CaO at a given SiO 2 level compared to metamorphic charnockites, and I-, S- and A-type granites. They form a distinctive type of intrusive igneous rocks, the Charnockite Magma Type (CMT or C-type), which generally lack hornblende and consist of …

of pink granite, green charnockite, and dark enderbite. A twelve-point Rb-Sr whole rock isochron for all three lithologies yields an age of 730 + 31 Ma and an initial 87Sr/86Sr of 0.7031 ± 1. Nearly concordant zircon ages for granite, charnockite, and enderbite are 744 + 2,742 + 2, and 739 + 2 Ma, respectively.

Charnockite is similar to granite in its outward appearance. It is a hypersthene-quartz-feldspar rock resembling 1. and 2. Platy quartz does not exist and can be used to distinguish it from 1.

Assessment of activity levels of radionuclides that exist in soil, granite, and charnockite rock samples is very crucial because it exhibits an enhanced elemental concentration of uranium (U) and thorium (Th) contributing higher natural background activity than usual in the environment and it may cause health risk to human health through the external and internal …

charnockite (which is part of the Lofoten suite). After emplacement, the charnockite of Hopen underwent high-pressure metamorphism, which converted fayalite+quartz to orthopyroxene (Ormaasen, 1977). Ormaasen (1977) thus recognizes two types of charnockites in the Hopen. Charnockite I retains primary Opx, whereas in Charnockite

The debate on charnockite nomenclature started with the usage of the term incipient charnockite to refer to orthopyroxene-garnet bearing dark greenish metamorphic dehydration zones (Pichamuthu, 1960) which have similar appearance and mineral assemblage to the charnockites at the type locality in southern India, described by Holland (1900).Such …

A particularly enigmatic example of charnockite-granite relations is found in southern Karnataka State. The outcrop of the Closepet Granite, a linear 250-km-long complex of intrusive granites, crosses the lower-grade craton from north to south and impinges upon the charnockitic terrane (Fig. 1). At this petrologic juncture, a charnockitic ...

The Charnockite rock series consists of several naturally occurring rocks which are a product of metamorphosis. Metamorphosis is the continual process of earthly debris being exposed to harsh weather conditions and pressure. This results in the formation of rocks, many of these rocks have a highly important application in var…

ELSEVIER Precambrian Research 79 (1996) 327-346 Pretumbrinn Resenrth Three generations of anorthosite-mangerite-charnockite-granite (AMCG) magmatism, contact metamorphism and tectonism in the Saguenay-Lac-Saint-Jean region of the Grenville Province, Canada Michael D. Higgins a, Otto van Breemen h a Sciences de la Terre, Universit~ du …

In this respect, charnockites associated with anorthosite-mangerite-charnockite-granite (AMCG) suites (e.g. Emslie, 1991) are interesting candidates as they often also …

The granite out-crop runs for nearly 500 km with an approximate width of 20 to 25 km and cut across the regional metamorphic structure passing from granulite facies in the South and green schist facies in the north. In the amphibolite-granulite facies transition zone the granite is intimately mixed with migmatites and charnockite. Field ...

Geochemically, the charnockite suite shows compositional variation from monzonite through granodiorite to granite, and based on Q-A-P classification, the rocks correspond to Opx-bearing granite (charnockite), granodiorite (opdalite or …

The occurrence of massif-type anorthosite intrusions is a widespread Proterozoic phenomenon. They are usually associated with gabbroic, charnockitic, and granitic rocks, comprising the so-called anorthosite-mangerite-charnockite-granite (AMCG) suite.

The charnockite–granite association of Okpella, although not yet dated, may be correlated to the charnockite–granite associations of Ado-Ekiti–Ikerre–Akure and Idanre in southwestern Nigeria which have yielded PanAfrican (Neoproterozoic) emplacement ages of 631 ± 18 Ma and 586 ± 5 Ma, respectively (Tubosun et al. 1984).

Charnockites, Opx-bearing (or more rarely fayalite-bearing) granitic rocks, make up only a tiny fraction of the granitic rocks worldwide. Despite their comparative rarity, over the …

The predominant rock types underlying the area include; granite gneiss, porphyritic granite, charnockite, and quartzite (Fig. ...

The Varberg–Torpa charnockite–granite association (Varberg, SW Sweden) consists of the magmatic Varberg charnockite (1399 ± 6 Ma) and the Torpa granite (1380 ± 12 Ma). The Torpa granite is both continuous and, based on its whole-rock geochemistry, synmagmatic with the Varberg charnockite. The granite body also contains a number of ...

However, if a granite contains fayalite, we contend that it is better to call a fayalite-granite than a charnockite. This is because the term "fayalite-granite" conveys more information than the term "charnockite". When one calls a rock a charnockite it tells the reader that the rock is a granitic rock that contains Opx (or rarely Fay).

Similar relationships have been inferred to exist between Proterozoic charnockite-granite associations in south- western Sweden (Hubbard, 1989), Nigeria (Olarewaju, 1987), and southern Natal (Thomas, 1988). Wones (1989) has argued that the intrinsic oxygen fugacity of a granitic magma is im- posed by the source materials. While this is likely ...

It is the replacement of the hydrous ferromagnesian mineral, biotite, by orthopyroxene, a mineral of similar composition, but anhydrous: in simple terms, charnockite is an 'anhydrous' granite. The name Charnockite was defined by Holland in 1900, in the name of Jacob Charnock (founder of Calcutta) whose tomb is made of this rock, which is ...

Brine- and CO 2-bearing fluid inclusions occur in Indian incipient charnockites of any age, Archean as well as NeoProterozoic.. Brines provide a genetic link between incipient-, massive charnockite, and Closepet Granite at Kabbal type locality, Karnataka. • Free fluids during metamorphism are further indicated by geodal textures and feldspar microveins lining coarse …

The mineralogy and petrology of the charnockite and surrounding granite are the same except for the presence of orthopyroxene ± clino-pyroxene in the charnockite. In addition, the charnockite is ...

Charnockites form an important component of the lower continental crust. Quantitative investigation on the properties of magmas that can stabilize orthopyroxene at solidi is crucial to...

Charnockite ("Seaweed Green Granite") - this Precambrian-aged garnetiferous charnockite is from Orissa State in the Eastern Ghats Orogenic Belt of eastern India. This rock is also known by the less slimy names "Pocono Green …

The major lithologic unit – the granitoids can be subdivided into TTG, charnockite, Closepet granite and anatectic granites/migmatites. The charnockite near Salem has two types of occurrence: one is massive, garnet-free and plutonic, crystallized at ~2560 Ma, and the other is gneissic, garnet-bearing and incipient, metamorphosed at ~2490 Ma. ...

The Neoproterozoic charnockite–granite association of Okpella intrudes metasedimentary and migmatite-gneiss complex rocks in the eastern Igarra Schist Belt, southwestern Nigeria. In order to unravel the complex processes involved in the formation and tectonic evolution of the Igarra Schist Belt during the Neoproterozoic, detailed field, …

Rocks of the charnockite series may be named by adding orthopyroxene to the normal igneous nomenclature (e.g. orthopyroxene-granite), but specific names are in widespread use such as norite, mangerite, enderbite, jotunite, farsundite, opdalite and charnockite (in the strict sense); equivalents of gabbro, monzonite, tonalite, monzodiorite ...

Granite and charnockite play an important role in ornamental materials, building materials, decorative materials, or kitchen counter tops. Igneous rocks (granite and charnockite) are known to contain minerals that can trap naturally occurring radioactive elements like uranium and …

RELATED MANGERITE-CHARNOCKITE-GRANITE (AMCG SUITE) JAMES McLELLAND Colgate University Hamilton, NY 13346 The Adirondack Mountains represent a southwestern extension of the Grenville Province via the Thousand Islands – Frontenac Arch region of the St. Lawrence River (Fig. 1). The region is topographically divided into

(1900) later defined charnockite as a quartz-feldspar-hypersthene-iron ore rock in the charnockite series and requested that the name should not be used for any hypersthene granite occurring in other petrographical provinces. The term charnockite series was used to express the grouping together in one petro-