Ok cool.
Like you said, earth is a very durable and strong element, although it is still very malleable and easily manipulated into various forms and constructs to help you in battle. Now earth chakra itself, is simply making your chakra more denser and solid. You can use earth to alter the enviorment, or create it from your own body. Earth chakra can be manipulated in several different forms, like a viscous mud, hard rock structures, or an almost loose sand like material or gravel. It's extremely versatile, you can use it to alter the terrain, and make it so that structures and plateaus rise or fall, and to alter the enviorment to give yourself an edge. It can be used defensively, offensively, and as a supplementary element altogether, because it is so so versatile. It's weak to lightning, because lightning can easily break it apart, and strong to water since it can easily absorb and stop the water. It's primarily used by those originating from Iwagakure, and is involved in the creation of the Steel and Lava release elements. Earth is strong, and slow moving, so it makes sound when emerging. Thus, you can use this to deduce if your opponent uses an earth release technique to attack you from behind or an angle you can't see. In addition, you'll often be able to hear and feel the ground itself changing form, giving you ample time to react and defend yourself.
Any questions on earth release?