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?
