Which one of the following statements concerning volcanic blocks and bombs is true?

Question

Quizplus · Accepted Answer

Volcanic blocks and bombs are formed from solidified lava ejected during volcanic eruptions. The outer layer of lava cools faster than the lava below, resulting in a black, rough texture. This is known as the surface crust, which makes up the outer layer of lava flows, and is often seen in blocks and bombs that have been ejected from the volcano. The orange color in photographs usually represents the hotter parts of the lava which are below the surface.

Which One of the Following Statements Concerning Volcanic Blocks and Bombs