________ occur at about the time of the first quarter and third quarter phases of the Moon.

Match the rock with the appropriate description.

________ has the same mineral composition as andesite.

________ is thought to form by partial melting and in situ crystallization of the melted portion.

The half-life of carbon-14 is about 6000 years. Assume that a sample of charcoal formed by burning of living wood 15,000 years ago. How much of the original carbon-14 would remain today?

________ has the same mineral composition as andesite.

When a permanent stream enters a desert area, what happens to its discharge?

Continental crust is generally thicker than oceanic crust.

________ occur at about the time of the first quarter and third quarter phases of the Moon.

Which one of the following statements is NOT true?