Lunar Meteorite: Pecora Escarpment (PCA) 02007

Antarctica  


  
The fusion crust of PCA 02007 is frothy because it is a gas-rich regolith breccia, like QUE 93069.
(NASA photo)
  
The "bottom" (left) and "top" (right) of the meteorite
(NASA photos)  

Backscattered-electon image of PCA 02007, a regolith breccia. At the top and right is the glassy, vesicular fusion crust that occurs on the outside of the meteorite in the photos above; the vesicles are black in the image. At the bottom is the brecciated interior of the meteorite. Longest dimension: 1.3 cm.
(image by Ryan Zeigler)

  

Transmitted-light photograph of the same thin section
(image by Ryan Zeigler)

  
Small chips of PCA 02007 in the lab. The green lines in the background are 2 mm apart. Click on image for enlargement.
(photos by Ryan Zeigler)
  


The regolith (soil) from which it derives had more exposure at the surface of the Moon than that of most regolith breccias. That's why it has such a vesicuar fusion crust and high concentrations of iridium from asteroidal meteorites.
  

Listed in The Meteoritical Bulletin, No. 88, Meteoritics & Planetary Science 39, A215–A272 (2004)

from Antarctic Meteorite Newsletter, vol. 26, no. 2, August, 2003

PCA 02007

Location: Pecora Escarpment
Field No.: 13690
Dimensions (cm): 4.0x3.5x1.0
Weight (g): 22.372

Lunar-Basaltic Breccia

[Randy's note: PCA 02007 is actually a feldspathic breccia, not a basaltic breccia.]

Macroscopic Description: Kathleen McBride. This is a disk shaped meteorite with brown exterior on the top portion of the rock. The bottom face has tan colored, ropy glass with a frothy appearance. Polygonal fractures and various clasts of different sizes, shapes and colors can be seen. The interior is composed of a hard, dark gray matrix with white clasts. Underneath the tan ropy glass is a layer of shiny green glass.

Thin Section (,4) Description: Tim McCoy, Linda Welzenbach. The section consists of an extremely fine-grained (melt?) matrix with isolated mineral grains and fine- to coarse-grained basaltic clasts in all size ranges up to 2 mm. Microprobe analyses reveal olivine of Fa27-33, pyroxene in a wide range of compositions from pigeonite Fs50Wo4 to augite of Fs19Wo43 with intermediate and more FeO-rich compositions, and plagioclase of An64-100 (with the most An96-100). The Fe/Mn ratio of the pyroxene averages ~53. The meteorite is a basaltic lunar breccia.



More Information

Meteoritical Bulletin Database

PCA 02007

Map

ANSMET location Map

References

Day J. M. D., Floss C., Taylor L. A., Anand M. and Patchen A. D. (2006) Evolved mare basalt magmatism, high Mg/Fe feldspathic crust, chondritic impactors, and the petrogenesis of Antarctic lunar breccia meteorites Meteorite Hills 01210 and Pecora Escarpment 02007. Geochimica et Cosmochimica Acta 70, 5957–5989.

Joy K. H. (2013) Trace elements in lunar plagioclase as indicators of source lithology (abstract). In 44th Lunar and Planetary Science Conference, abstract no. 1033.

Joy K. H., Crawford I. A., Russell S. S., Swinyard B., Kellett B., and Grande M. (2006) Lunar regolith breccias MET 01210, PCA 02007 and DAG 400: Their importance in understanding the lunar surface and implications for the scientific analysis of D-CIXS data (abstract). In Lunar and Planetary Science XXXVII, abstract no. 1274, Lunar and Planetary Institute, Houston.

Joy K. H., Crawford I. A., Russell S. S., and Kearsley A. T. (2010) Lunar meteorite regolith breccias: An in situ study of impact melt composition using LA-ICP-MS with implications for the composition of the lunar crust. Meteoritics & Planetary Science 45, 917–946.

Joy K. H., Zolensky M. E., Nagashima K., Huss G. R., Ross D. K., McKay D. S., and Kring D. A. (2012) Direct detection of projectile relics from the end of the lunar basin–forming epoch. Science, 10.1126/science.1219633.

Korotev R. L. (2005) Lunar geochemistry as told by lunar meteorites. Chemie der Erde 65, 297–346.

Korotev R. L., Zeigler R. A., and Jolliff B. L. (2004) Compositional constraints on the launch pairing of LAP 02205 and PCA 02007 with other lunar meteorites (abstract), Lunar and Planetary Science XXXV, abstract no. 1416, Lunar and Planetary Institute, Houston.

Korotev R. L., Zeigler R. A., and Jolliff B. L. (2006) Feldspathic lunar meteorites Pecora Escarpment 02007 and Dhofar 489: Contamination of the surface of the lunar highlands by post-basin impacts. Geochimica et Cosmochimica Acta 70, 5935–5956.

Korotev R. L., Jolliff B. L., and Zeigler R. A. (2010) On the origin of the moon’s feldspathic highlands, pure anorthosite, and the feldspathic lunar meteorites (abstract). In Lunar and Planetary Science XLI, abstract no. 1440, 41st Lunar and Planetary Science Conference, Houston.

Liu Y. Zhang A. Taylor L. A. (2009) Fragments of asteroids in lunar rocks (abstract). 72th Annual Meeting of the Meteoritical Society, number 5434.

Nishiizumi K., Hillegonds D. J., and Welten K. C. (2006) Exposure and terrestrial histories of lunar meteorites LAP 02205/02224/02226/02436, MET 01210, and PCA 02007 (abstract), In Lunar and Planetary Science XXXVII, abstract no. 2369, Lunar and Planetary Institute, Houston.

Taylor L. A., Anand M., Neal C., Patchen A., and Kramer G. (2004) Lunar meteorite PCA 02 007: A feldspathic regolith breccia with mixed mare/highland components (abstract), Lunar and Planetary Science XXXV, abstract no. 1755, Lunar and Planetary Institute, Houston.

Taylor L. A, Patchen A., Floss C, and Taylor D. (2004) An unusual meteorite clast in lunar regolith breccia, PCA 02-007 (abstract). Meteorit. Planet. Sci. 39, Suppl, A105.

Vaughan W. M., Wittmann A., Joy K. H., Lapen T. J., and Kring D. A. (2011) Provenance of impact melt and granulite clasts in lunar meteorite PCA 02007 (abstract). In Lunar and Planetary Science XLII, abstract no. 1247, Lunar and Planetary Institute, Houston.

Zeigler R. A., Korotev R. L., and Jolliff B. L. (2004) Petrography of lunar meteorite PCA 02007, a new feldspathic regolith breccia (abstract). In Lunar and Planetary Science XXXV, abstract no. 1978, Lunar and Planetary Institute, Houston.


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Prepared by:

Randy L. Korotev


Department of Earth and Planetary Sciences
Washington University in St. Louis


Please don't contact me about the meteorite you think you've found until you read this and this.

e-mailkorotev@wustl.edu

Last revised: 05-Mar-2014