KREEP stands for potassium (atomic symbol K), rare earth elements (REE), and phosphorus (P). KREEP-rich basalts are found on the Earth's Moon. KREEPs are also enriched in uranium and thorium. General Name, Symbol, Number potassium, K, 19 Chemical series alkali metals Group, Period, Block 1, 4, s Appearance silvery white Atomic mass 39. ... Rare earth ore The rare earth elements are a relatively abundant group of 17 chemical elements (see Periodic Table) composed of scandium, yttrium, and the lanthanides. ... This article is about the chemical element. ... Basalt Basalt is an extrusive igneous rock, sometimes porphyritic, and is often both fine-grained and dense. ... Earth, also known as the Earth, Terra, and (mostly in the 19th century) Tellus, is the third-closest planet to the Sun. ... Crust composition Oxygen 43% Silicon 21% Aluminium 10% Calcium 9% Iron 9% Magnesium 5% Titanium 2% Nickel 0. ... General Name, Symbol, Number uranium, U, 92 Chemical series actinides Group, Period, Block ?, 7, f Appearance silvery gray metallic Atomic mass 238. ... General Name, Symbol, Number thorium, Th, 90 Chemical series transition metals Group, Period, Block ?, 7, f Appearance silvery white Atomic mass 232. ...

More than 4.5 billion years ago the surface of the Moon was a liquid magma ocean. It is believed that KREEPs represent the last chemical remnants of that magma ocean after the lunar crust formed. KREEPs floated to the surface because their component elements are "incompatible", that is, they did not incorporate into compact crystal structures. KREEPs are used by scientists to trace the volcanic history of the Moon and to record the impacts by meteorites. This article is about the type of molten rock. ... This article is about the type of molten rock. ... Rose des Sables (Sand Rose), formed of gypsum crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... This article is about volcanoes in geology. ... Bacubirito in Culiacan, Mexico is the second largest meteorite in the Americas, and fifth largest in the world A meteorite is a small extraterrestrial body that reaches the Earths surface. ...

A part of one of the rock samples collected on Apollo 12, lunar sample 12013, has a composition which is remarkably similar to some tektites. It is especially similar to high-magnesium javenites (part of the Australasian strewn field). Sample 12013 is inhomogenous in that it is composed of two types of materials, light and dark. The light, acidic portion is composed of up to 71 percent silicon dioxide. The dark portion resembles KREEP rocks. The abundances of 20 of 23 elements tested from the acidic portion of the sample showed a striking similarity to high-magnesium tektites. The major elements matched well, the minor and trace elements did not. However, other lunar samples matched some microtektites very well. A tektite Tektites (from Greek tektos, molten) are natural glass objects, up to a few centimeters in size, which — according to most scientists — have been formed by the impact of large meteorites on Earths surface, although a few researchers favor an origin from the Moon as volcanic ejecta. ...

Results from Lunar Prospector's gamma ray spectrometer shows that KREEP-containing rocks are concentrated in the Mare Imbrium rim, the nearside maria and highlands near Imbrium and the Mare Ingenii South Pole-Aitken basin and are distributed at a lower level in the highlands. The distribution seen by Lunar Prospector supports the idea that the impact which formed Mare Imbrium excavated KREEP-rich rocks and ejected them over the Moon and the South Pole-Aitkin basin impact also exposed KREEP-rich material. NASAs Lunar Prospector The Lunar Prospector mission was the third selected by NASA for full development and construction as part of the Discovery Program. ... This article is about electromagnetic radiation. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Oblique view of Mare Imbrium looking south towards Copernicus crater. ... The Lunar maria (singular: mare, pronounced MAH-ray) are large, dark, basaltic plains on Earths Moon, formed by ancient basaltic flood eruptions caused by extremely large meteoroid impacts. ... Located on the Moons southern hemisphere, Mare Ingenii (sea of cleverness) is one of the few lunar mare features on the far side of the Moon. ... The South Pole-Aitken basin is an impact crater on Earths Moon. ...