Isotopes of the same element vary in their number of:

Geologists recognize which three major types of plate boundaries?

Which of the following is not an important difference between continental crust and oceanic crust?

Ocean crust is composed mostly of what?

Which of the following acts to keep a rock solid (instead of melting)?

Which of the following features are not associated with a divergent plate boundary?

 At transform plate boundaries, ________.  

What is formed when the leading edges of two plates overlap and one plate descends into the mantle?

Continental-continental convergent zones are typically indicated by which feature?

An example of a sulfate mineral: