Alright.
Earth can act in a few ways. It can seem to flow, like when an earthquake strikes, or it can be sturdy and rigid, like how it is naturally. Earth is a solid and sturdy element.
Earth Release can let water flow through it or it can absorb water. When used with water, you can create mud. When combined with water, you can use the KG Wood. It can fuse with fire to make lava or it can let the fire rest atop of it. When used with fire, sometimes it can be a super heated earth, almost lava. It can let wind and lightning pass through it or stop it in its tracks. Lightning can easily pierce through earth and break it apart. When someone can combine fire, wind, and earth, one can create the powerful dust, or particle, element. Also Earth is capable of being crystalized and isn't dense enough to stop it.
In both Dark release forms earth itself cannot be absorbed and can serve as a shield to block the release. Steel can overpower earth. Boil can corrode it. Earth cannot contain the explosion of explosion release but can create an extra medium for sound to pass through thus proving to overcome sound. Both Earth and water have substance which make them weak to dust.