plagiograniten.
/ˌpleɪdʒɪəˈɡranᵻt/, U.S. /ˈˌpleɪdʒiəˈɡrænət/ Geology.
Any of a range of granitic rocks, occurring particularly in ophiolites, which are low in potassium and rich in sodic plagioclase feldspar.
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the world > the earth > structure of the earth > constituent materials > rock > igneous rock > [noun] > plutonic rocks > granite > varieties of
moorstone1461
silver stone1758
granitell1794
granitoid1794
rapakivi1794
ophthalmite1811
protogine1823
pegmatite1824
potash-granite1845
beresite1849
granitite1875
greisen1878
trowlesworthite1884
microgranite1888
charnockite1893
alaskite1900
Dartmoor granite1904
plagiogranite1959
1932 A. Johannsen Descriptive Petrogr. Igneous Rocks II. 382 ‘Plagioclase-granite’. Long Bay, Virgin Gorda, West Indies.]
1959 Bull. Volcanologique 20 177 The development of folding processes, accompanied by deep fractures, brought about the formation of a complicated intrusive magmatic complex consisting of gabbro-amphibolites, ultrabasites, plagiogranites, spessartites and acid Na granitoids.
1985 R. Thorpe & G. Brown Field Descr. Igneous Rocks x. 133/2 The white ‘anorthositic’ rocks of ophiolites are usually rich in sodium-rich plagioclase feldspar and some of them contain substantial amounts of quartz (up to 30%), so that the term plagiogranite is more appropriate.
1996 Mining Jrnl. (Nexis) 19 Jan. 50 The gold mineralisation is hosted by granite and plagiogranite dykes associated with overthrusts and shear zones.
This entry has been updated (OED Third Edition, June 2006; most recently modified version published online March 2022).
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n.1959