Tal

Elemental Plane of Earth

It is a place of hidden riches.
It is a wall against all foes.
It is a grave for the greedy.

- Manual of the Planes

Planar Movement

Tul has a planar period of 800 days and a terminal period of 40 days. Tal primarily affects Nemas by shifting tectonic plates and creating massive earthquakes throughout the plane. These can be powerful enough to create new mountains or level existing ones.
During its coterminous period, Nemas experiences disruptive earthquakes, quite dangerous to the denizens of Nemas. As per every elemental plane, elevated power of related magics and an increase in associated elemental creature sightings occur during the coterminous period. The increased power of magics does not manifest in everyday spellcasting. It does, however, increase the amount of earth-based energy in the plane and allows for rituals to channel more than the usual amount. The Taluun Family spends most of the conterminus period on a constant vigil to divert any earthquakes away from Lonnhaven.
During Tul's aterminous period, Nemas experiences significantly less earthquakes. Opposite of the coterminous state, the aterminous state sees a decrease in related elemental magics and associated creatures of Tul are infrequently seen.

Geography

The Elemental Plane of Earth was an infinite expanse of solid matter pockmarked by bubbles of other elements and riddled with fissures and tunnels created by burrowing creatures or the occasional small mining operation. Ensconced in a few of these pockets were trading outposts and the rare hidden wizard fortress. Solid does not imply stationary: the substances of this plane were constantly moving in a slow, grinding motion punctuated by earthquakes from small tremors to massively violent upheavals. Open spaces were gradually filled by the relentless shifting (or marauding earth elementals) unless action was taken to prevent it. Air could be found in scattered pockets but unbreathable gasses were also present—unprepared travelers lucky enough to arrive in a cavern might slowly asphyxiate while the unlucky quickly suffocated by being buried alive. Other pockets of magma, water, ooze, dust, or ash were particularly dangerous for miners if they accidentally breached one of these. No light existed in the Plane of Earth except for rare luminous gems buried in the crushing darkness. Travelers able to pass through stone were effectively blind unless they used magic such as a ring of x-ray vision, or until their ocular organs reached an open space where darkvision could operate or a source of light could be produced. Hearing was actually enhanced while encased in earth, to the point where travelers could detect any movement through the rock within a certain radius of their position.
Every type of rock, soil, mineral, metal ore, sand, and dirt could be found here in abundance, ranging from talc soft to marble tough to diamond hard. Mining operations tended to be small and short-lived because the movement of the substance of the plane and intense gravity caused cave-ins, and the native population defended their territory and/or food supply. In addition, there was the unusual problem of where to put the discarded mine tailings. The dao were the only people known to successfully manage large continuous mining operations in the Plane of Earth.

Fauna & Flora

The matter of the plane itself comes alive, the earth elementals were the most numerous creatures on the plane, with typically blocky, angular bodies covered in sharp edges, ranging from man-sized to mountainous. Other native creatures looked like rough-hewn statues of Prime Material Plane animals and monsters or animated crystalline forms. Then there were the alien-looking xorn and xaren with tri-fold symmetric bodies and a taste for metal. All natives and some creatures with an earth-affinity could move through the plane like a fish through water, the rock flowing around them and closing back up again, leaving no tunnel.
Immigrants and visitors to the Elemental Plane of Earth included basilisks, the dao, dwarves, an occasional blue or copper dragon, galeb duhr, gargoyles, mephits of the earth and salt subtypes, and stone giants.

References

Elemental Plane of Earth | forgottenrealms.wikia : A majority of content relating to Flora and Fauna and Geography was gathered from this location.

Type

Dimensional plane