1. D dripstone produced by buildup of minerals precipitated from groundwater.
Water drips down from, for example, the roof of a cave and slowly leaves behind mineral deposits which form a shape similar to an icicle
2. D running water cuts small channels into a slope
Rill erosion is formed by soil removal from small streams of running water. They form based on how the water falls down a slope and tend to migrate to already depressed or softer areas of soil.