of Earth Science |Northeastern
TO EARTH SCIENCE
Objectives #15 (October 17, 2006)
By the end of today’s class, you should be able to do the
* Explain the relationship between cooling rate and crystal size
of an igneous rock.
* Define and describe what is meant by mafic and felsic
mineralogic compositions of igneous rocks.
* Describe the igneous rocks basalt and granite
in terms of their crystal size and mineralogic composition.
* Describe the difference in viscosity
between molten mafic and molten felsic material.
* Explain why molten material occurs in the earth's crust, particularly
explaining decompression melting and the role of water.
* Explain how magmas of different viscosity lead to differences in eruptive style
of a volcano and differences in the material erupted (including
volcanic lava, gas, and pyroclastics).
* Make a profile sketch of each of the three types of volcanoes (shield
volcanoes, cinder cones, and composite cones), explaining why each one
has its particular shape.
* Plot volcano locations on a world map, and determine how they relate
to plate tectonic boundaries.
* Describe the connection between plate tectonic environment, type of
volcano that would be found there, and type of material that would be
extruded from that type
* Draw a sketch showing how and why volcanoes form in a subduction zone.
© 2006 Laura L. Sanders. Last updated October 16, 2006.