Exam 3: Igneous Rocks

Porphyritic rocks rarely contain any visible phenocrysts.

In a cooling andesite magma with pyroxene and calcic plagioclase, what will those minerals react to as the magma continues to lose heat?

The introduction of water as a flux or decompression are thought to be the main triggers to melt peridotite and generate basalt in the upper mantle.

Minerals, such as plagioclase feldspar in the continuous branch of Bowen's reaction series, react with the magma to form lower temperature, more stable minerals such as hornblende or biotite.

What is the most common extrusive rock type for any volcanic environment on the Earth or even on the Moon?

Match the description with the appropriate texture. -________ a magnifying glass or microscope is needed to see individual mineral grains

In a porphyritic volcanic rock, which mineral grains are the last to crystallize?

Briefly explain two ways that felsic magmas can originate.

________ is the term for the liquid portion of magma.

Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. -Choose the option that does not fit the pattern.

An important reaction series showing the expected order in which minerals crystallize from magma was named for its originator.Who was this Canadian scientist?

What process is exhibited by the diagram below? When does this process take place?

Which tabular, discordant igneous rock body intruded along a nearly vertical crack or fissure?

What is the rock colour (total % of dark minerals)of a typical gabbro or basalt?

Consider Bowen's reaction series.Which mineral would you expect to see as a phenocryst in a porphyritic basalt?

Which statement best describes the crystallization of magmas?

The size of crystals in igneous rocks is generally a function of the rate of cooling.However, within the same rock crystal size does not necessarily reflect the order of crystallization for individual minerals.Without using Bowen's Reaction Series, how might you determine the order of crystallization of minerals in an individual rock sample? (Hint: Think about the texture.)

What would you call an aphanitic, vesicular, black rock having small pale green phenocrysts of olivine and small white lath shaped phenocrysts of plagioclase?

Technically, the process whereby ions arrange themselves into orderly patterns during the cooling of a liquid is called ________.

What is a small, flat floored, dome shaped, igneous rock body emplaced at shallow depths by uplift and arching of the overlying, older strata?