Search Results

anorthosite original

broader	anorthositic rock original
definition	Anorthositic rock that contains between 0 and 5 percent quartz and no feldspathoid mineral in the QAPF fraction. QAPF field 10.

anorthositic rock original

broader	phaneritic igneous rock original
definition	Leucocratic phaneritic crystalline igneous rock consisting essentially of plagioclase, often with small amounts of pyroxene. By definition, colour index M is less than 10, and plagiclase to total feldspar ratio is greater than 0.9. Less than 20 percent quartz and less than 10 percent feldspathoid in the QAPF fraction. QAPF field 10, 10*, and 10'.
narrower	anorthosite original foid bearing anorthosite original quartz anorthosite original

anthracite / anthrazit original

broader	coal / kohle original
definition	Coal that has vitrinite mean random reflectance greater than 2.0% (determined in conformance with ISO 7404-5). Less than 12-14 percent volatiles (dry, ash free), greater than 91 percent fixed carbon (dry, ash free basis). The highest rank coal; very hard, glossy, black, with semimetallic luster, semi conchoidal fracture.

anthropogenic material original

broader	compound material original
definition	Material known to have artificial (human-related) origin; insufficient information to classify in more detail.
narrower	anthropogenic unconsolidated material original

anthropogenic unconsolidated material original

broader	anthropogenic material original unconsolidated material original
definition	Unconsolidated material known to have artificial (human-related) origin.

aphanite original

broader	rock original
definition	Rock that is too fine grained to categorize in more detail.

aplite original

broader	phaneritic igneous rock original
definition	Light coloured crystalline rock, characterized by a fine grained allotriomorphic-granular (aplitic, saccharoidal or xenomorphic) texture; typically granitic composition, consisting of quartz, alkali feldspar and sodic plagioclase.

arenit / arenite original

broader	sandstone original
definition	Clastic sandstone that contains less than 10 percent matrix. Matrix is mud-size silicate minerals (clay, feldspar, quartz, rock fragments, and alteration products) of detrital or diagenetic nature.

ash and lapilli original

broader	tephra original
definition	Tephra in which less than 25 percent of fragments are greater than 64 mm in longest dimension

ash breccia bomb or block tephra original

broader	tephra original
definition	Tephra in which more than 25 percent of particles are greater than 64 mm in largest dimension. Includes ash breccia, bomb tephra and block tephra of Gillespie and Styles (1999)