Mafic igneous rocks are enriched in ___.
a) silica
b) quartz
c) magnesium, iron and calcium
d) sodium
e) potassium
Ans: c) magnesium, iron and calcium
You might also like to view...
Critical Thinking
Which two terrestrial ecosystems in the accompanying figures produce the least kilocalories of energy per year?
What will be an ideal response?
How long will it take to add another billion people to the world's population given the current growth rate?
A. 12 years B. 2 years C. 22 years D. 50 years
Most of India's rapidly growing electricity demand is being met by what source?
A) coal B) nuclear C) wind D) dung E) hydropower
What is a wave period?
a. The horizontal distance between two successive crests or troughs b. The number of waves passing a fixed point per second c. The time for a wave to move the distance of one wavelength d. The end of a wave train