Qapf Volcanic. Total alkali sodium plus potassium expressed as oxides is a fair proxy for the alkali or a to p modal dimension of the volcanic qap diagram and silica total silicon as sio 2 is a fair proxy for the quartz or q direction. The qapf diagrams for plutonic and volcanic rocks look almost the same fig 1 1 except that field 15 is subdivided into 3 fields in volcanic rocks and rocks no rocks have been assigned to fields 1 and 1a of the volcanic qapf diagram.
Igneous Rock Composition Chart Illustrates Generalized Mineral Composition Of Volcanic Magma Gabbros Plutonic And Igneous Rock Igneous Rock Identification from in.pinterest.com
Using a volcanic qapf diagram what would 55 plagioclase 7 olivine and 36 clinopyroxene be. The classification separates and individually classifies the pyroclastic carbonatitic melititic lamprophyric and charnockitic rocks before entering the main qapf classification for plutonic and. An exact name can be given only if the mineralogical composition is known which cannot be determined in the field.
Qapf diagram is used to classify plutonic rocks.
The classification separates and individually classifies the pyroclastic carbonatitic melititic lamprophyric and charnockitic rocks before entering the main qapf classification for plutonic and. Show transcribed image text. 1 not defined 2 alkali feldspar rhyolite 3 rhyolite 4 dacite 5 plagidacite 6 alkali feldspar trachyte 6 quartz bearing alkali feldspar trachyte 6 foid bearing alkali feldspar trachyte 7 trachyte 7 quartz trachyte 7 foid bearing trachyte 8 latite. An exact name can be given only if the mineralogical composition is known which cannot be determined in the field.
