Three settings are described below in which three different classes of rocks form. Fill in the blanks by indicating which class of rocks is the result.
a. Along the coast, waves carry sand out into deeper, quieter water, where it accumulates, gradually becoming buried. A rock formed form sand grains cemented together is..........
b. Thich flows of glowing red lava engulf farms and villages on the flanks of Mt. Etna, a volcano in Sicily. The cold, black rock formed when these flows are cool enough to walk on is........
c. The broad tundra plains of northern Canada expose gray, massive rock that formed many kilometers below a mountain belt. This rock, exposed only after the overlying rock was stripped away, is......