Crystalline rock from the highlands of the Moon, enriched in potassium (chemical symbol K), rare earth elements (abbr. REE), and phosphorus (chemical symbol P). The presence of KREEP rocks suggests that chemical separation has occurred within the Moon. Such rocks usually have high concentrations of uranium and thorium, which are radioactive and therefore produce heat, so KREEP rocks were important to the Moon's internal development.
Subjects: Earth Sciences and Geography — Astronomy and Astrophysics.