Later This site tells the story of the history of the universe. Click Earlier and Later to follow the story. The rain fell on the rocks of the volcanoes and weathered them. Weathering can happen in several ways.
Rain can enter cracks in the rock.
At night it freezes into ice and expands, breaking open the rock. Rain also contained chemicals called acids which can attack the rock. . The rock broke down into sand , clay and minerals . These were carried along in streams but the sand and clay soon sank to the bottom. The minerals were carried away in the streams which collected to make the first oceans .