What is anorthosite rock used for?
Anorthosite is an almost monomineralic, feldspathic rock with a great variety of industrial applications (Table 1). Anorthosite massifs are known to host important ore depos- its such as ilmenite and are, in many cases, excellent sources for high-quality rock aggregate and also for dimension- stone.
Is there anorthosite on Earth?
anorthosite, type of intrusive igneous rock composed predominantly of calcium-rich plagioclase feldspar. All anorthosites found on Earth consist of coarse crystals, but some samples of the rock taken from the Moon are finely crystalline. Anorthosite is also found on the lunar surface. …
What is lunar anorthosite?
Lunar anorthosite is a major rock of the lunar highlands, which formed as a result of plagioclase-floatation in the lunar magma ocean (LMO). Constraints on the sufficient conditions that resulted in the formation of a thick pure anorthosite (mode of plagioclase >95 vol.
What is special about anorthosite?
It seems anorthosites are by far interested by geologists because they give us great information about Earth history and how it was evolved in planetary geology. Also, it has no plate tectonics and due to lack of a true atmosphere it has no erosion and weathering alike the earth.
Why was anorthosite important to Apollo team?
These are the Moon’s oldest rocks—more than 4 billion years old—and covered the young Moon’s entire surface before its crust was pummeled and broken up by asteroids and comets. Anorthosite rocks brought back to Earth by Apollo astronauts have helped researchers learn about the Moon’s geologic history.
What kind of minerals are found in an anorthosite?
Mineral elements like amphibole, ilmenite, magnetite, olivine, pyroxene and spinel are the mafic minerals also often present. Anorthosite is a phaneritic type of intrusive igneous rock featured by a predominance of plagioclase feldspar (90-100%) and a nominal mafic component (0-10%).
What is the plagioclase content of an anorthosite?
However, anorthosites are defined by a high plagioclase content (90–100% plagioclase), and are not found in association with contemporaneous ultramafic rocks. This is now known as ‘the anorthosite problem’. Proposed solutions to the anorthosite problem have been diverse, with many of the proposals drawing on different geological subdisciplines.
How are ultramafic rocks related to anorthosites?
Though co-eval, these rocks likely represent chemically-independent magmas, likely produced by melting of country rock into which the anorthosites intruded. Importantly, large volumes of ultramafic rocks are not found in association with Proterozoic anorthosites.
What is the composition of labradorite in anorthosite?
Mineralogically, labradorite is a compositional term for any calcium-rich plagioclase feldspar containing between 50–70 molecular percent anorthite (An 50–70), regardless of whether it shows labradorescence. The mafic mineral in Proterozoic anorthosite may be clinopyroxene, orthopyroxene, olivine, or, more rarely, amphibole.
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