Multiple Choice
As the silica content varies from less than 40% to more than 70% there is a systematic ________.
A) decrease in calcium, magnesium, and iron with an increase in sodium and potassium
B) increase in calcium, magnesium, and iron with a decrease in sodium and potassium
C) increase in the temperature at which point melting begins
D) decrease in the quartz content of the rocks
Correct Answer:
Verified
Correct Answer:
Verified
Q30: Pegmatites consist of what size mineral grains?
Q43: What term denotes the larger mineral grains
Q155: The aphanitic equivalent of diorite is<br>A)andesite<br>B)basalt<br>C)komatiite<br>D)rhyolite
Q157: Basalt is the aphanitic or fine-grained equivalent
Q158: _ typically exhibit pyroclastic textures.<br>A)Granites<br>B)Gabbros<br>C)Diorites<br>D)Welded tuffs
Q161: A _ is an open cavity in
Q162: A porphyritic texture includes two different sizes
Q163: Aphanitic means that individual crystals are so
Q164: Felsic rocks have silica contents of _
Q165: Examine the words and/or phrases for each