{"thcode":4,"term":{"code":"3.4","name":"Felsic volcanic rock","parent":"3","scope":"A light-colored, fine-grained or aphanitic extrusive or hypabyssal rock, with or without phenocrysts and composed chiefly of quartz and feldspar."},"uf":[],"bt":[{"code":"3","name":"Volcanic rock","parent":"0","scope":"A generally finely crystalline or glassy igneous rock resulting from volcanic action at or near the Earth's surface, either ejected explosively or extruded as a lava.  The term includes near-surface intrusions that form a part of the volcanic structure."},{"code":"0","name":"Earth material","parent":null,"scope":"Geologic map unit classification (Bruce R. Johnson) version 6.2: A hierarchical classification of earth materials for digital geologic maps."}],"nt":[{"code":"3.4.1","name":"Alkali-feldspar rhyolite","parent":"3.4","scope":"A volcanic rock defined in the QAPF diagram as having Q\/(Q+A+P) between 20 and 60% and P\/(P+A) < 10%..."},{"code":"3.4.5","name":"Alkali-feldspar trachyte","parent":"3.4","scope":"A volcanic rock defined in the QAPF diagram as having Q\/(Q+A+P) < 20% or F\/(F+A+P) < 10%, and P\/(P+A) < 10%..."},{"code":"3.4.4","name":"Dacite","parent":"3.4","scope":"A volcanic rock defined in the QAPF diagram as having Q\/(Q+A+P) between 20 and 60% and P\/(P+A) > 65%..."},{"code":"3.4.8","name":"Latite","parent":"3.4","scope":"A volcanic rock defined in the QAPF diagram as having Q\/(Q+A+P) < 5% or F\/(F+A+P) < 10%, and P\/(P+A) between 35 and 65%..."},{"code":"3.4.7","name":"Quartz latite","parent":"3.4","scope":"A volcanic rock defined in the QAPF diagram as having Q\/(Q+A+P) between 5 and 20% and P\/(P+A) between 35 and 65%..."},{"code":"3.4.3","name":"Rhyodacite","parent":"3.4","scope":"A volcanic rock defined in the QAPF diagram as having Q\/(Q+A+P) between 20 and 60% and P\/(P+A) between 35 and 65%..."},{"code":"3.4.2","name":"Rhyolite","parent":"3.4","scope":"A volcanic rock defined in the QAPF diagram as having Q\/(Q+A+P) between 20 and 60% and P\/(P+A) between 10 and 35%..."},{"code":"3.4.6","name":"Trachyte","parent":"3.4","scope":"A volcanic rock defined in the QAPF diagram as having Q\/(Q+A+P) < 20% or F\/(F+A+P) < 10%, and P\/(P+A) between 10 and 35%..."}],"rt":[]}