Benev Selec, also known as Drema IV, was the inhabited fourth planet of the Selcundi Drema system. This system was located in the Selcundi Drema sector and was the homeworld of the Dremans, a humanoid species, whose civilization was classified by the Federation, in 2365, as pre-warp.
In that year, the USS Enterprise-D became the first manned Starfleet starship to survey the planet. An analysis by the planetary geosciences division aboard the ship into the cause of the planet's geologically unstable state was discovered to be the result of the largest deposit of dilithium ore ever recorded. The ore was laid in an unusual pattern, with the crystals forming perfectly aligned lattices. This action was turning the ore into a generator strata which produced a piezoelectric effect. In plain English, "The crystals take the natural radiant heat of the planet, focus it, and turn it into mechanical energy which increases tectonic stresses that tear the planet apart. And then the crystals break down, which is why we found all these traces of Illium-629."
During the mission, Lieutenant Commander Data detected a low-level RF signal sent by a Dreman girl, Sarjenka. She asked if there was "anyone out there", prompting Data to respond. Data informed Captain Picard of his contact with Sarjenka after he learned that Drema IV was on the verge of self-destruction. Because Data's actions violated the Prime Directive, Picard initially ordered Data to sever all contact with the surface. However, when he heard Sarjenka's voice, telling Data she was afraid, he decided that they must act.
The survey team, headed by acting Ensign Wesley Crusher, suggested that harmonic vibrations emitted by class-1 probes fitted with resonators fired into the planet would shatter the planet's dilithium lattices and thus alleviate the tectonic stresses tearing the planet apart. The plan was a success and the planet was saved from destruction. (TNG: "Pen Pals")
Background information Edit
The planet's name - Benev Selec - was seen in an okudagram in Data's quarters aboard the Enterprise-D. According to the Star Trek Encyclopedia (4th ed., vol. 1, p. 77), Benev Selec was the name of Drema IV's system.