Exam 3: Igneous Rocks

Exceptionally coarse grained felsic plutonic rocks that are rich in rare minerals and trace elements are probably ________.

What do pumice and obsidian have in common?

Briefly explain how magma compositions can change through magma mixing.

Intrusive rocks are named for the old God "Trudere".

Intermediate rocks like andesite and diorite ________.

Which magma is most likely to quench (congeal)to a natural glass?

Name the texture that requires a magnifying glass or microscope to see individual mineral grains.

In general, what happens in terms of composition as crystallization proceeds down the Bowen's reaction series?

Which texture would be most unlikely to occur in an extrusive igneous rock?

What type of igneous rock is both glassy and highly vesicular?

Yellowstone National Park is most famous for what?

________ is a pyroclastic igneous rock with fragments smaller than 2 mm.

What is the role of water and other volatiles that are driven from the descending plate in the diagram below?

What tabular, nearly horizontal, igneous rock body is intruded concordantly between layers of older sedimentary rock?

What is the average temperature rise below Earth's surface due to the geothermal gradient?

Compared to volcanic rocks, plutonic ones have many more crystals in the same volume.

Magmas rise to shallower depths and intrude the crust or extrude on the surface because ________.

Which of the following best describes an aphanitic texture?

What weight percentage of silica (SiO?)typifies granites and rhyolites?

The process of ________ is driven by ________ and transforms a magma into an igneous rock.