PHSC 211 Chapter 2 Quiz (Fall 2020)

PHSC 211 Chapter 2 Quiz (Fall 2020) 1. What mineral composition is most characteristic of felsic rocks? a. olivine, pyroxene, and calcium-rich plagioclase b. orthoclase, quartz, and biotite c. calcium-rich plagioclase and hornblende with some olivine d. particles of volcanic ash welded together ans b 2. What mineral composition is most characteristic of mafic rocks? a. olivine, pyroxene, and calcium-rich plagioclase b. orthoclase, quartz, and biotite c. sodium-rich plagioclase, hornblende, and quartz d. particles of volcanic ash welded together ans a 3. What mineral composition is most characteristic of intermediate rocks? a. olivine, pyroxene, and calcium-rich plagioclase b. orthoclase, quartz, and biotite c. sodium-rich plagioclase and hornblende with some quartz or biotite d. particles of volcanic ash welded together ans c 4. When mafic lava breaks through fissures in the continental crust, which of the following often results? a. lava plateaus b. composite volcanoes c. lava domes d. pyroclastic sheets ans a