Lunar terrane

KREEP is an acronym built from the letters K (the atomic symbol for potassium), REE (rare-earth elements) and P (for phosphorus),[3] and is a geochemical component of some lunar impact breccia and basaltic rocks.

The PKT is on the near side of the moon, and covers 10% of the lunar surface,[4] or 16% if one includes the maria lying within the FHT.

[6] KREEP has been shown to lower the melting point of rocks similar to those found on the Moon, and is expected to have contributed to volcanism in the region.

Human and robotic missions have been done to this terrane, and samples have been returned to Earth for further study.

[8][9] The Felspathic Highlands Terrane (alternatively Feldspathic), or FHT, is composed predominantly of ancient anorthositic materials.

It is thought to be part of the FHT, with the differences being due to modification by ejecta from impacts in other terranes.

No spacecraft have landed on the inner FHT, as the only lander to the far side touched down in the South Pole-Aitken Terrane.

Visually, the maria correspond to the dark regions of the Moon, and the terra to the light.

Thorium concentrations on the Moon. The large area of high concentration on the Near Side (left) corresponds to the Procellarum KREEP Terrane, and the smaller area on the Far Side (right) to the South Pole–Aitken Terrane. The large purple area to the north of this includes the Felspathic Highlands Terrane, which is not reflected in thorium concentrations.
The SPAT corresponds to the darker region in the far side of the moon.