Exam 3: Igneous Rocks

Match the description with the appropriate texture. -________ mineral grains are of roughly equal size and coarse enough to be seen without a microscope or magnifying glass

The phaneritic equivalent of basalt is

Pyroxene, hornblende, and biotite are all minerals found on the ________ series of Bowen's Reaction Series.

Which of the following igneous rocks exhibit phaneritic texture?

Mafic rocks have silica contents of ________ and are mainly composed of ________.

Melting of rocks to form magma as a result of decreased pressure is known as ________.

The size, shape, and geometric arrangement of mineral grains in igneous rocks is called ________ and it indicates ________.

What is/are thought to be the main mechanism(s)for generating basaltic melts from hot peridotite near its melting point in the upper mantle?

________ is composed mainly of ferromagnesian minerals.

The aphanitic equivalent of granite is

What phenocryst minerals would you expect to find in an aphanitic rhyolite flow?

Which of the following igneous rocks usually exhibit aphanitic texture?

Three processes contribute to the formation of every igneous rock: ________.

Match the description with the appropriate texture. -________ magma cools and consolidates without growth of mineral grains

Magmatic differentiation is the term geologists use for the classification and naming of igneous rocks.

Tabular sills and lava flows often have regular geometric grids of vertically oriented, thermal shrinkage cracks called ________.

What igneous texture refers to rocks composed mainly of mineral and volcanic fragments?

How much silica do felsic igneous rocks commonly contain?

Light coloured aphanitic rocks ________.

What would you name an intermediate coloured, coarse fragmental volcanic rock with large amphibole and plagioclase phenocrysts?