Igneous rock with more than 50% carbonate minerals
Carbonatite
Igneous rock
Carbonatite from Jacupiranga, Brazil. This rock is a mixture of calcite, magnetite, and olivine.
Composition
Carbonate minerals (>50%)
Carbonatite lava at Ol Doinyo Lengai volcano, Tanzania
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, or as dikes, sills, breccias, and veins.[2] They are almost exclusively associated with continental rift-related tectonic settings. It seems that there has been a steady increase in the carbonatitic igneous activity through the Earth's history, from the Archean eon to the present.
Nearly all carbonatite occurrences are intrusives or subvolcanic intrusives. This is because carbonatite lava flows, being composed largely of soluble carbonates, are easily weathered and are therefore unlikely to be preserved in the geologic record. Carbonatite eruptions as lava may therefore not be as uncommon as thought, but they have been poorly preserved throughout the Earth's history.[3]
Carbonatite liquid compositions are significantly more alkaline than what is preserved in the fossil carbonatite rock record as composition of the melt inclusions shows.[4]
Only one carbonatite volcano is known to have erupted in historical time, the active Ol Doinyo Lengai volcano in Tanzania. It erupts with the coolest lava in the world, at 500–600 °C (932–1,112 °F). The lava is natrocarbonatite dominated by nyerereite and gregoryite.
^Stoppa, Francesco; Jones, Adrian P.; Sharygin, Victor V. (2009). "Nyerereite from carbonatite rocks at Vulture volcano: implications for mantle metasomatism and petrogenesis of alkali carbonate melts". Central European Journal of Geosciences. 1 (2): 131–51. doi:10.2478/v10085-009-0012-9. S2CID 130277058.
^Guzmics, Tibor; Mitchell, Roger H.; Szabó, Csaba; Berkesi, Márta; Milke, Ralf; Ratter, Kitti (2012). "Liquid immiscibility between silicate, carbonate and sulfide melts in melt inclusions hosted in co-precipitated minerals from Kerimasi volcano (Tanzania): evolution of carbonated nephelinitic magma". Contributions to Mineralogy and Petrology. 164 (1): 101–22. Bibcode:2012CoMP..164..101G. doi:10.1007/s00410-012-0728-6. S2CID 129035814.
Carbonatite (/kɑːrˈbɒnəˌtaɪt/) is a type of intrusive or extrusive igneous rock defined by mineralogic composition consisting of greater than 50% carbonate...
coarse-grained variety (or facies) of carbonatite, an intrusive, igneous rock. The fine-grained variety of carbonatite is known as alvikite. The two varieties...
lithium, copper, gold, coal, iron ore, and other minerals. The Khanashin carbonatite in Helmand Province contains 1,000,000 tonnes (980,000 long tons; 1,100...
typically 1 to 4 m wide. They consist of massive carbonatites that are mostly devoid of vesicles. The carbonatite rocks have been dated as having cooled between...
these are planets which are rich in carbon. Chemical composition: The carbonatites contain a groundmass of fluorite and sylvite, while apatite, galena,...
include: Carbonatite and natrocarbonatite lavas are known from Ol Doinyo Lengai volcano in Tanzania, which is the sole example of an active carbonatite volcano...
Boninite – Ultramafic extrusive rock high in both magnesium and silica Carbonatite – Igneous rock with more than 50% carbonate minerals Charnockite – Type...
include: Carbonatite and natrocarbonatite lavas are known from Ol Doinyo Lengai volcano in Tanzania, which is the sole example of an active carbonatite volcano...
The Panda Hill Carbonatite is an apatite and pyrochlore bearing sovite carbonatite located in the Mbeya District of Tanzania. The deposit was found in...
variety of leucitite. Kresten, Peter; Troll, Valentin R. (2018). "The Alnö Carbonatite Complex, Central Sweden". GeoGuide. doi:10.1007/978-3-319-90224-1....
rifts are characterized by volcanoes that erupt unusual alkali lava or carbonatites. Examples include the volcanoes of the East African Rift. A volcano needs...
aluminophosphates, presumably derived from weathering of the Proterozoic Mount Weld carbonatite. The primary commercial interest at the site is targeted towards oxides...
46 km (29 mi) from Dharmapuri and 199 km (124 mi) from Chamrajnagar. Carbonatite rocks in this site are considered to be the oldest of its kind in South...
mines in the world. Weathering supergene enrichment of an apatite rich carbonatite in Ontario has produced a significant eluvial phosphate ore deposit....
tinguaite, lamprophyre micromalignite, lamprophyre micromelteigite, or carbonatite. The Beemerville Alkaline Complex also includes several lamprophyric...
igneous rocks with other essential minerals are very rare, but include carbonatites, which contain essential carbonates. In a simplified compositional classification...
augite syenite, gabbro, etc. To the west and southwest are Palaeozoic carbonatite complexes at Kangerlussuaq (Gardiner complex) and Safartoq, and basic...
Ngualla is a Proterozoic carbonatite estimated to be about 1,000 million years old and is a plug-like intrusive carbonatite with a diameter of approximately...
record, and learn about prehistoric cultures and ecosystems. For example, carbonatite tephra found at Oldoinyo Lengai (a volcano in the East African Rift Valley)...
rare type of magma called a carbonatite that is highly enriched in carbonates and low in silica. Cooling bodies of carbonatite magma give off highly alkaline...
quartz, feldspar, spodumene, petalite, and rare lithophile elements. Carbonatites are an igneous rock whose volume is made up of over 50% carbonate minerals...
PMID 17807346. S2CID 3101604. Woolley, A. R. (1987). Alkaline Rocks and Carbonatites of the World, Part 1: North and South America. London, British Museum...
is composed of relics of carbonatite intrusion, now appearing as carbonatite ring and subsided central part. The carbonatite ring is characterized by...
Fenite is a metasomatic alteration associated particularly with carbonatite intrusions and created, very rarely, by advanced carbon dioxide alteration...
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