Lakeview Mountain Tonalite
Field Collector: Esper Signius Larsen Jr.
Place Collected:Near Perris, CA Elisnore Quadrangle, Southern California
Object number: ROC21695
DescriptionPlutonic, coarse-grained (majority of grains > 5 mm) igneous rock composed of almost half and half black and white mineral grains. Consisting of 60% white plagiocalse (5-10 mm), 15% very light-grey quartz (granular), 15% black prismatic hornblende crystals (~1 cm), and 10% black biotite plates (~1 cm).