Consider a sample of porphyritic andesite, which is common in Pacific Rim volcanoes. Speculate how this sample may have formed (simply defining porphyritic isn't enough, be specific)
What will be an ideal response?
Answer: The formation of porphyritic igneous rocks typically involves a two-stage cooling process. Deep inside the volcano the minerals that form andesite begin to crystallize. As the volcano erupts, the liquid portion of the lava cools rapidly, inhibiting mineral growth and thus creating two crystal sizes within the groundmass. Hornblende is a typical phenocryst for andesite.
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Discuss how Bowen's reaction series helps explain the composition of many igneous rocks
Another term for isobaric chart is ____________________
Fill in the blank with correct word.
The two primary motions of the Earth are ________ and ________
Fill in the blank(s) with correct word
Which of the following signs is commonly associated with heat emergencies?
A. Muscle cramps B. Slow breathing C. Strong pulse D. Bradycardia