{"thcode":4,"term":{"code":"4.5.4.2","name":"Troctolite","parent":"4.5.4","scope":"A plutonic rock satisfying the definition of gabbro, in which pl\/(pl+px+ol) is between 10 and 90% and px\/(pl+px+ol) is less than 5%."},"uf":[],"bt":[{"code":"4.5.4","name":"Gabbro","parent":"4.5","scope":"A plutonic rock defined in the QAPF diagram as having Q between 0 and 5% or F\/(F+A+P) < 10%, P\/(A+P) greater than 90% and plagioclase more calcic than An50"},{"code":"4.5","name":"Gabbroid","parent":"4","scope":"A plutonic rock with Q < 20% or F < 10%, P\/(A+P) > 65%, and pl\/(pl+px+ol) between 10 and 90%."},{"code":"4","name":"Plutonic rock","parent":"0","scope":"A rock formed at considerable depth by crystallization of magma and\/or by chemical alteration.  It is characteristically medium- to coarse-grained, of granitoid texture."},{"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":[],"rt":[]}