Ch 6 #2 reading quiz

Which of the following can help make rocks melt beneath Earth's surface? ___ increasing pressure ___ adding volatiles ___ increasing temperature ___ increasing density ___ decrease pressure

adding volatiles increasing temperature decrease pressure

Order the following elements from most frequently occurring to least frequently occurring in Earth's crust. calcium oxygen iron silicon aluminum

oxygen silicon aluminum iron calcium

If all of the following rocks were to completely melt and reach the same final temperature, which would produce magma with highest viscosity? basalt gabbro andesite diorite rhyolite

rhyolite

Match the type of magma with both the color of rock expected and the temperature of the magma below. 1. basaltic 2. andesitic 3. rhyolitic ___ 1,000-1,300 degrees C ___ Medium Gray ___ light colored ___ black to dark gray ___ 800-1,000 degrees C ___ 600-900 degrees C

1 2 3 1 2 3

The following prompts all list ways that viscosity can be altered. Drag the prompts to the correct area. 1. less viscous 2. more viscous ___ increase SiO2 content ___ increase temperature ___ increase mineral crystal content

2 1 2

Rock may melt by _______________. lowering the pressure on it raising its temperature increasing its water content All of these choices are correct.

All of these choices are correct.

The viscosity of magma is lowered by __________. increasing temperature decreasing crystal content decreasing SiO2 content All of these choices are correct.

All of these choices are correct.

Why does the magma from some volcanoes flow smoothly and relatively peacefully, while the magma from other volcanoes blasts forth violently and deals death over wide areas? differences in the chemical and mineral makeup of magmas variations in the temperature, water and gas content, and viscosity of magmas different geographic positions with respect to hot spots and edges of tectonic plates All of these choices are correct.

All of these choices are correct.

__________ melting occurs when a rock melts due to a lowering of pressure. Release Uplift Elevation Ascension Decompression

Decompression

Identify the parts of table by dragging the answers that identify the parts of the volcanic materials to the appropriate space below.

Table 6.5 Volcanic Material names

The presence of water ________ the melting point of rock. raises lowers does not change may raise or may lower

lowers

Which of following correctly lists the order in which the listed minerals form in a cooling magma from the first to the last to form? quartz, biotite mica, amphibole, pyroxene, and olivine olivine, pyroxene, amphibole, biotite mica, and quartz pyroxene, biotite mica, calcite, quartz, and potassium-rich feldspar quartz, potassium-rich feldspar, pyroxene, biotite mica, and calcite

olivine, pyroxene, amphibole, biotite mica, and quartz

In magma, __________ is the most abundant dissolved gas. water vapor (H2O) carbon dioxide (CO2) sulfur dioxide (SO2) hydrogen sulfide (H2S) carbon monoxide (CO)

water vapor (H2O)