Chronicles of Time
These are planes that exist and exude one element of existence. The Elemental plane of Fire for example is a plane of existence which exists and exudes fire. Fire of the other planes theoretically comes from the Elemental plane of Fire. Energy from elemental planes flows and bleeds into other planes, and the mixing of the elements gives form to much of the other planes.
Elemental Planes are NOT ruled by Gods, but are ruled by Elements.
There are also Quasi-Elemental planes, which are pocket planes to more then one elemental plane bleeding together to create mixed elemental planes. The the Qausi-elemental plane of Lava is an example, where the planes of Fire and Earth have mixed.
Death on an Elemental plane is usually not pleasant, whoever, MOST typically can be resurrected from. The only exception is if someone tied to the planes elemental opposition dies, the ruling elemental Lord my claim and smother the spirit to prevent resurrection, however elemental Lords would normally have no reason to otherwise do this.