Answer:
The crust precipitated from water that once covered the earth.
Explanation:
Neptunists versus Plutonists. The origin of rocks became a topic of controversy between two schools of geologists near the end of the 1700s. The Neptunists held that all crustal rock was precipitated from an ocean that covered the entire earth before the beginning of life. The Plutonists, on the other hand, believed that what we today call igneous rock has a different origin. The Plutonists believed that these rocks arrived at the surface of the earth as molten rock, called lava. Geological field observations solved the controversy in favor of the Plutonists. Basalt, hardened lava, was traced to the volcanic vent from which it had erupted.
