The great lunar hot spot and the composition and origin of the Apollo mafic (“LKFM”) impact‐melt breccias

Korotev, R. L.

doi:10.1029/1999je001063

Cited by 129 publications

(201 citation statements)

References 62 publications

Supporting

Mentioning

187

Contrasting

Order By: Relevance

“…Korotev [2000] argued that the crystallization of the last dregs of the magma ocean not only was prolonged but also experienced a renewed thermal activity, which resulted in the remelting of the magnesian cumulates below the crust. The latter appear in that stratigraphic position because of the overturn of the cumulate pile of the magma ocean [Ryder, 1991;Hess and Parmentier, 1995].…”

Section: Introductionmentioning

confidence: 99%

“…The generally accepted view of the lunar magma ocean is of a monotonically cooling large magma body, perhaps involving the entire Moon, which totally solidified within 100-200 Myr of the formation of the Moon [Taylor, 1982 Haskin and colleagues [Haskin, 1998;Wieczorek and Phillips, 2000;Korotev, 2000] suggest that the high-Th geochemical province is the product of the final stages of crystallization of the magma ocean. Korotev [2000] argued that the crystallization of the last dregs of the magma ocean not only was prolonged but also experienced a renewed thermal activity, which resulted in the remelting of the magnesian cumulates below the crust.…”

Section: Introductionmentioning

confidence: 99%

“…Wieczorek and Phillips [2000] predict that the residual KREEP layer remains partially molten for a few billion years and that this layer provides sufficient thermal energy to partially melt the deep interior and produce mare basalts. The magnesian suite troctolites and norites which are characterized by very refractory major element compositions but highly incompatible element contents [Papike et al, 1997] are believed to be products of this KREEP liquid which has dissolved substantial quantities of magnesian cumulates [Korotev, 2000] (but see Hess [2000]). …”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Thermal evolution of a thicker KREEP liquid layer

Hess¹,

Parmentier²

2001

J. Geophys. Res.

View full text Add to dashboard Cite

Abstract. We consider the thermal evolution of the thickened potassium, rare earth element, and phosphorous (KREEP) liquid layer that extends over a significant fraction of the lunar nearside with a prescribed thickness and heat production and beneath an insulating anorthosite crust. This layer represents a subcrustal heat source beneath the Procellarum-Imbrium terrane and may be responsible for the localized and anomalous enrichments of highly incompatible elements in this terrane. In some models this thickened liquid layer is the thermal source for the remelting of mare basalts and also produces the parent magmas of the magnesian suite. Indeed, a KREEP liquid layer thickened from 5 to 10 km with more than 200 times chondritic heat-producing elements does not continue to cool but undergoes a reheating and grows in thickness by dissolving several times its mass of anorthosite and ultramafic cumulates. However, such a liquid layer cannot give rise to the parent magmas to the magnesian suite, because it cannot account for the extraordinarily high incompatible element content, the primitive major element content, or the positive /•nd of the magnesian suite. This growing layer will also form an impenetrable barrier to the eruption of mare basalts and is generally inconsistent with a number of geophysical constraints of the Moon, specifically, the existence of mascons subsequent to the basin filling by mare basalts. A thickened KREEP liquid layer can, however, explain the asymmetry in the distribution of KREEP-rich rock on the lunar crust. Such a KREEP layer must be efficiently cooled and be quickly solidified to avoid some of the difficulties described above. A thinned anorthosite crust would allow efficient heat loss and induce crystallization of such a layer early in lunar history.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Thermal evolution of a thicker KREEP liquid layer

Hess¹,

Parmentier²

2001

J. Geophys. Res.

View full text Add to dashboard Cite

show abstract

“…We can use the distribution of [Th] for this purpose because its distribution is most cylindrical as judged by the close equality between its first and second eigenvalues. Histograms of the front and back side distributions of [Th] [Jolliff et al, 2000;Haskin et al, 2000;Korotev, 2000]. The extent of the PKT (defined here by [Th] !…”

Section: Intermediate Quadrupole Moment Axesmentioning

confidence: 99%

“…[5] These observations have been interpreted to imply that for some unknown reason, most of the lunar inventory of KREEP (and its associated contents of U, Th, and K) was concentrated on the near side of the Moon within a province called the Procellarum KREEP Terrane (PKT) [Jolliff et al, 2000;Korotev, 2000;Haskin et al, 2000;Wieczorek and Phillips, 2000]. The net result was a local enhancement of U and Th that is some 300 times their chondritic relative abundances.…”

Section: Introductionmentioning

confidence: 99%

Global distribution of lunar composition: New results from Lunar Prospector

et al. 2002

View full text Add to dashboard Cite

[1] Maps of thorium [Th], [FeO], the ratio of epithermal to thermal neutrons (E/T), and fast neutrons (FN) from Lunar Prospector were studied to determine their global distribution on the Moon. These distributions are compared to that of the 750 nm lunar albedo from Clementine to aid in their interpretation. All distributions were parameterized using a spherical harmonic expansion out to order l = 30. Resultant harmonic coefficients generally decrease with increasing l value as a power law in l for all five variables. The axes of all dipole components (l = 1) cluster closely about a centroid given by +14.1°latitude and 16.4°west longitude. This location is very close to the symmetry axes of their quadrupole components (l = 2), which cluster about a centroid given by +24.6°latitude and 25.1°west longitude. Both centroids are near the center of a suggested Procellarum basin, given by Whitaker [1981] at +23°latitude and 15°west longitude. This suggestion is strengthened by a sharp decrease of the intensities of all three variables at $50°from the centroids, which is close to the boundary of the putative Procellarum basin. The coincidence of the global concentration of heat-producing elements (through [Th]) and mare deposits on the lunar surface (through [FeO], [T/E], and [FN]) with the circular outline of a putative Procellarum basin suggests that the events that were responsible for producing Oceanus Procellarum (perhaps a single giant impact) must figure importantly in shaping the global distribution of surface composition. A second, apparently older circular structure having its center near À5°latitude and 65°east longitude and a radius of 50°is also hinted at in the data.

show abstract

Apollo 17 and the Moon

Schmitt

2003

Encyclopedia of Space Science and Technology

View full text Add to dashboard Cite

Apollo 17 was not the last flight of humans to the Moon. More lunar exploration and even lunar settlement will occur, baring the future stagnation or disappearance of our civilization. Exploration and scientific investigations in the earth sciences are rarely complete, particularly for studies related to a specific field site. A long hiatus between field investigations may occur, but other forms of investigation, directly or indirectly related, continue. Apollo 17's field study of the Valley of Taurus‐Littrow on the Moon in 1972 and subsequent examination of its significance to our understanding of the origin and evolution of that small planet and of our own constitute a good example of these facts of scientific life. As the third of the specifically “science” missions to the Moon in the twentieth century, Apollo 17 actually became the last lunar landing of the Apollo Program in September 1970 rather than on 11 December 1972 when the mission reached Taurus‐Littrow. The National Aeronautics and Space Administration (NASA) and the Administration of President Richard M. Nixon, with the acquiescence of the Congress, had concluded that no further planned amortization of the American taxpayer's investment in deep space exploration would be undertaken. The scientists became increasingly interested in an unnamed, 2300‐m deep, 50‐km long valley, radial to the 740‐km diameter circular basin, Serenitatis, that cut through the Taurus Mountain ring near the crater Littrow. This Valley of “Taurus‐Littrow,” however, was not a favorite of the operational mission planners. In spite of the pinpoint landing accuracy they had demonstrated on all previous missions since Apollo 11, the narrow valley, the mountainous approach, and the high valley walls gave the planners pause. Their legitimate concerns were compounded by the relatively short time, only 14 minutes, for navigational updates after acquisition of communications from the lunar module, Challenger, as its last orbit before landing carried it around the Moon from the farside. Initially, trajectory calculations indicated that three‐sigma errors, the normal extremely conservative planning limit, might result in hitting the side of the northern mountain wall. Gradually, however, refinements in navigational techniques for the mission and the inevitable synergistic give and take that so characterized Apollo interactions narrowed the three‐sigma errors to about 1 km, the limit where all agreed that Taurus‐Littrow could be the selected site. Thus, in late February 1972, only 9 months from launch, Taurus‐Littrow was approved as the exploration site for Apollo 17. The Valley of Taurus‐Littrow offered four major benefits as the last Apollo landing site, taken in the context of a final test of then current hypotheses related to the origin and evolution of the Moon. First, photogeologic analysis indicated that Taurus‐Littrow provided access to a three‐dimensional window into a mountain ring created by the Serenitatis large basin‐forming event, by now well established as the result of a giant impact of an asteroid or comet. Second, major units of mare basalt and older nonmare rocks would be within easy reach of roving vehicle traverses. Third, a mantle of dark, possibly young volcanic debris partially covered the region as well as portions of the valley, and craters of a range of depths penetrated this debris and the underlying basalt. And, fourth, the valley lies about 600 km north and 200 km east of the Apollo 11 and Apollo 15 sample areas, respectively, adding significantly to our exploration coverage of the Moon's nearside. Due to the foreknowledge that Apollo 17 would be the last of the Apollo series, selection of its landing site became a contentious issue among lunar scientists and between lunar scientists and operational planners. Impact cratering, origin and evolution of the Moon were subjects of Apollo 17's scientific informers and enquiries and are discussed.

show abstract

The great lunar hot spot and the composition and origin of the Apollo mafic (“LKFM”) impact‐melt breccias

Cited by 129 publications

References 62 publications

Thermal evolution of a thicker KREEP liquid layer

Thermal evolution of a thicker KREEP liquid layer

Global distribution of lunar composition: New results from Lunar Prospector

Apollo 17 and the Moon

Contact Info

Product

Resources

About