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Sanukite
{{No footnotes, date=December 2021 Sanukitoids are a variety of high-Mg granitoid found in convergent margin settings. The term "sanukitoid" was originally used to define a variety of Archean plutonic rock, but now also includes younger rocks with similar geochemical characteristics (Shirey & Hanson 1984; Rogers et al. 1985; Stern et al. 1989; Kelemen et al. 2004). They are called "sanukitoid" because of their similarity in bulk chemical composition to high-magnesium andesite from the Setouchi Peninsula of Japan, known as "sanukites" or "setouchites" (Tatsumi and Ishizaki 1982). Sanukite rocks are an andesite characterized by orthopyroxene as the mafic mineral, andesine as the plagioclase, and a glassy groundmass. Rocks formed by processes similar to those of sanukite may have compositions outside the sanukitoid field. The term was originally defined by Stern et al. (1989) to refer to plutonic rocks containing between 55 and 60 weight percent SiO2, with Mg# >0.6, Ni >100 ppm, Cr > ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithophone
A lithophone is a musical instrument consisting of a rock or pieces of rock which are struck to produce musical notes. Notes may be sounded in combination (producing harmony) or in succession (melody). It is an idiophone comparable to instruments such as the glockenspiel, vibraphone, xylophone and marimba. In the Hornbostel-Sachs classification system, lithophones are designated as '111.22' – directly-struck percussion plaques. Notable examples A rudimentary form of lithophone is the "rock gong", usually a natural rock formation opportunistically adapted to produce musical tones, such as that on Mfangano Island, in Lake Victoria, Kenya. The Great Stalacpipe Organ of Luray Caverns, Virginia, USA uses 37 stalactites to produce the Western scale. Other stalactite lithophones are at Tenkasi in South India, and at Ringing Rocks Park in Pennsylvania. An example that is no longer used is at Cave of the Winds, in Colorado Springs. The Txalaparta (or Chalaparta), a tradition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
