Quartz latite is intermediate between
latite and
rhyolite in its mineralogy.
Description
Quartz latite is the fine-grained equivalent of a
quartz monzonite, containing approximately equal amounts of
plagioclase and
alkali feldspar and between 5% and 20%
quartz and with
plagioclase making up 35% to 65% of its total
feldspar content. Quartz latite is not a recognized rock type in the
TAS classification used to chemically classify glassy or very fine-grained volcanic rock.[1][2][3][4]
Occurrence
Quartz latite is found in the 130-135
Mya Etendeka Formation of
Namibia, where it forms extensive sheets in association with
tholeiitic basalt. These are interpreted as densely welded ash flow
tuffs.[5] Some of the quartz latite flows were enormous, with estimated volumes of 2,320 cubic kilometers (560 cu mi) and 6,340 cubic kilometers (1,520 cu mi) for two of the flows.[6]
Paleoproterozoic quartz latite is abundant in the Roxby Downs area of Australia, and may have been a source rock for younger
granitoids.[7]
Quartz latite is found at the
Bingham mine in
Utah in association with its plutonic counterpart, quartz monzonite.[8]
^Philpotts, Anthony R.; Ague, Jay J. (2009). Principles of igneous and metamorphic petrology (2nd ed.). Cambridge, UK: Cambridge University Press. pp. 139–143.
ISBN9780521880060.
^Milner, Sc; Duncan, Ar; Ewart, A (February 1992). "Quartz latite rheoignimbrite flows of the Etendeka Formation, north-western Namibia". Bulletin of Volcanology. 54 (3): 200–219.
Bibcode:
1992BVol...54..200M.
doi:
10.1007/BF00278389.
S2CID54998997.
^Creaser, Robert A. (September 1996). "Petrogenesis of a Mesoproterozoic quartz latite-granitoid suite from the Roxby Downs area, South Australia". Precambrian Research. 79 (3–4): 371–394.
Bibcode:
1996PreR...79..371C.
doi:
10.1016/S0301-9268(96)00002-2.
^Parry, W. T.; Ballantyne, G. H.; Wilson, J. C. (1 November 1978). "Chemistry of biotite and apatite from a vesicular quartz latite porphyry plug at Bingham, Utah". Economic Geology. 73 (7): 1308–1314.
Bibcode:
1978EcGeo..73.1308P.
doi:
10.2113/gsecongeo.73.7.1308.