Which rock, formed by the solidification of thin layers of molten lava, comprises much of the surfaces-of Mercury, Venus, Mars and the Moon?
Evidence of water on Mars found by Mars Reconnaissance Orbiter formed by groundwater rising up depositing minerals and cementing sediments. The hardned layers are consequently more protected from erosion. This process may occur instead of layers forming under lakes. Sometimes the layers display different colors. Light-toned rocks on Mars have been associated with hydrated minerals like sulfates. The Mars Rover Opportunity examined such layers close-up with several instruments. Some layers are probably made up of fine particles because they seem to break up into fine dust. In contrast, other layers break up into large boulders so they are probably much harder. Basalt, a volcanic rock, is thought to form layers
Geology of Venus Geology of Venus Venus is a planet with striking geology. Of all the other planets in the Solar System, it is the one nearest to Earth and most like it in terms of mass, but has no magnetic field or recognizable plate tectonic system. Much of the ground surface is exposed volcanic bedrock, some with thin and patchy layers of soil covering, in marked contrast with Earth, the Moon, and Mars. Some impact craters are present, but Venus is similar to Earth in that there are much fewer craters than on the other rocky planets that are largely covered by