The origin of KREEP.
Abstract
The concept of 'urKREEP' (primeval KREEP), a magma residuum hypothetically produced early in lunar history by fractional distillation of the global magma ocean which hypothetically created the lunar crust, is used to explain the origin of KREEPy lunar rocks. The incompatible-rich last dregs of the magma ocean left their trace in the form of incompatible patterns that show no relative fractionation from site to site on the moon and that, with the exception of minor fractionals in two pristine clasts, are the same in pristine samples as in breccias. The high concentration on the lunar surface of these urKREEP remnants demands a high efficiency in upward transport of the incompatibles. This transport may have been enhanced by urKREEP's presumably low density and by high temperatures produced by radioactive decay in the K-, U-, and Th-rich residuum.
- Publication:
-
Reviews of Geophysics and Space Physics
- Pub Date:
- February 1979
- DOI:
- 10.1029/RG017i001p00073
- Bibcode:
- 1979RvGSP..17...73W
- Keywords:
-
- Astronomical Models;
- Lunar Composition;
- Rare Earth Elements;
- Chemical Composition;
- Crystallization;
- Fusion (Melting);
- Incompatibility;
- Isotropic Media;
- Lunar Crust;
- Lunar Soil;
- Magma;
- Ocean Models;
- Temperature Distribution;
- ORIGIN;
- KREEP;
- CONCENTRATIONS;
- MOON;
- ROCKS;
- BRECCIAS;
- POTASSIUM;
- RARE EARTH ELEMENTS;
- PHOSPHORUS;
- PETROGENESIS;
- PARTIAL MELTING;
- MAGMAS;
- OCEAN;
- ANORTHOSITE;
- PLAGIOCLASE;
- PRISTINE ROCKS;
- FRACTIONAL CRYSTALLIZATION;
- THORIUM;
- 12013;
- 64815;
- 15386;
- 72275;
- 15405;
- 15382;
- 15272;
- REVIEW;
- APOLLO 15;
- APOLLO 16;
- APOLLO 17;
- Moon Samples:Chemical Composition