Search results
Results from the WOW.Com Content Network
Carbonatite (/ kɑːrˈbɒnəˌtaɪt /) is a type of intrusive or extrusive igneous rock defined by mineralogic composition consisting of greater than 50% carbonate minerals. [ 1 ] Carbonatites may be confused with marble and may require geochemical verification. Carbonatites usually occur as small plugs within zoned alkalic intrusive complexes ...
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. [1] 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 km 2.
The Fen Complex is a roughly circular area about three kilometres in diameter. It is located just west of the Oslo graben. Radiometric age dating on the carbonatites gave an age of 539 +/- 14 Myr. The host rocks for the intrusions are middle Proterozoic granites and gneiss and the complex was associated with the Cambrian rifting of the cratonic ...
Specimen 7.5 cm) Sovite (or sövite) is the coarse-grained variety (or facies) of carbonatite, an intrusive, igneous rock. The fine-grained variety of carbonatite is known as alvikite. [1] The two varieties are distinguished by minor and trace element compositions. [2] Sovite is often a medium-to-coarse-grained calcite rock with variable ...
Natrocarbonatite. Natrocarbonatite is a rare carbonatite lava which erupts from the Ol Doinyo Lengai volcano in Tanzania within the East African Rift of eastern Africa. Natrocarbonatite lavas were first documented in 1962, by J. B. Dawson. [1][2]
Rare earths are contained in secondary phosphates and aluminophosphates, presumably derived from weathering of the Proterozoic Mount Weld carbonatite. [4] The primary commercial interest at the site is targeted towards oxides as well as further niobium and tantalum deposits within the intrusive pipe of the Mount Weld carbonatite, which is approximately three kilometers (1.9 mi) in diameter.
Carbonate rocks are a class of sedimentary rocks composed primarily of carbonate minerals. The two major types are limestone, which is composed of calcite or aragonite (different crystal forms of CaCO 3), and dolomite rock (also known as dolostone), which is composed of mineral dolomite (CaMg (CO 3) 2). They are usually classified based on ...
Gregoryite is an anhydrous carbonate mineral that is rich in potassium and sodium [5] with the chemical formula (Na 2,K 2,Ca)CO 3. [2] [6] [7] It is one of the two main ingredients of natrocarbonatite, found naturally in the lava of Ol Doinyo Lengai volcano of Arusha Region, Tanzania, and the other being nyerereite.