Prelab/Lab 3

Convergent

What plate tectonic process was responsible for the formation of composite volcanoes?

Divergent

What plate tectonic process was responsible for the formation of fissure eruptions?

Transform

What plate tectonic process was responsible for the formation of shield volcanoes?

High silica, built up pressure

Describe the hazards associated with composite volcanoes

Ultramafic

Green

Fine-grained

A textual term for rock consisting of many fine grains or clasts

Sedimentary Rock

Along the coast, waves carry sand out deeper, quieter water, where it accumulates and gradually becomes buried. A rock formed from sand grains cemented together is _______

Mafic

Black

Hilltop

Concentric contour lines indicate a _________

Close depression

Concentric hachured contour lines indicate a ___________

Upstream

Contour lines form a V when they cross a stream. The open part of the V faces the ________ direction

Effusive

Does low viscosity magma lead to more explosive or more effusive eruptions?

Coarse-grained

Generally indicated magmas that slowly cooled deep underground

Intermediate

Grey

Felsic

Light colored

Contour lines

Lines of equal elevation

Magma

Molten rock beneath the earths surface

Lava

Molten rock that has flowed out onto the earths surface

Intrusive

Rock formed by the freezing of magma underground

Extrusive

Rock that forms by the freezing of lava above ground, after it flows or explodes out onto the surface and comes into contact with the atmosphere or ocean

True

T/F - Composite volcanoes are more explosive than shield volcanoes

False

T/F - Metamorphic rocks undergo tremendous heat and pressure and can eventually melt and become magma

False

T/F - Sedimentary rocks cannot become igneous rocks

True

T/F - Weathering of any type of rock can form sediments that cement to form sedimentary rocks

Metamorphic Rock

The broad tundra plans of Northern Canada expose gray, massive rock that formed many kilometers below a mountain belt. This rock, exposed only after the overlying rock was stripped away, is ______________

Viscosity

The resistance of a fluid to flow

Steepness of slopes, Gentle slopes

The spacing between contour lines on a map reveals the ________ on the ground surface. Widely spaced contour lines indicate ___________

Igneous Rock

Thick flows of glowing red lab engulf farms and villages on the flanks of Mount Etna, a volcano in Sicily, Italy. The cold, black, rock formed when these flows are cooled enough to walk on is ____________

Each line represents a separate elevation, and you can't have two different elevations at the same point

Two different contour lines cannot cross because

Composite volcanoes

Volcanoes with high viscosity; Explosive; Pyroclastic flow, ash fall, Lahars

Shield volcanoes

Volcanoes with low viscosity (magma to gas, silica); Effusive

High silica/High gas

What conditions are required for the most explosive types of eruptions?

Silica Content

Which factor had more of an effect on the type of volcano formed: silica content or gas content?