New Insights into the Complex History of Lunar Highlands: Alha 81005 under Reinvestigation

نویسنده

  • J. Gross
چکیده

Introduction: Lunar meteorites come from random sites on the Moon (including areas not visited by Apollo or Lunar missions) and so are crucial for understanding the development of the whole moon, and as ground truth for lunar remote sensing. Data from the Lunar Prospector and Clementine spacecraft show that, relative to the Apollo and Luna landing sites, most of the lunar surface has low abundances of FeO and incompatible elements [3; 4], with an average composition more like that of the feldspathic lunar meteorites [5]. We have started a re-investigation ALHA81005 to improve our understanding of unsampled areas of the Moon and enlarge our knowledge of lunar highland rock types and the Moon’s early history. Sample and Method: Antarctic meteorite Allan Hills A81005 is a ploymict, anorthositic regolith breccia from the lunar highlands [6,7]. Its clasts include granulites, FAN, mare basalts, impact melts, and impact glasses. Clasts described here were analyzed from the polished thin section ALHA81005,9. Mineral analyses were performed using an electron microprobe (Cameca SX100) at NASA JSC. Operating conditions were 15kV accelerating voltage, 20nA, focused beam and a measuretime of 20-40s per element. Standards included well characterized natural and synthetic materials. Lithic and Mineral Clasts: ALHA 81005 contains a wide range of rock and mineral fragments, most of which are granulites and anorthosites [13,7]. Other rock types are rare, and some mineral fragments must represent other lithologies.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Granulite Clasts of Intermediate Mg* in Lunar Meteorite Alha 81005: Chemical Compositions and Origins

Lunar highland meteorites contain fragments of metamorphic granulites with a wide range of Mg* (molar Mg/(Mg+Fe)) [1], between that of Mg-suite plutonics and magnesian anorthositic granulites (MAG), and those of ferroan anorthosites (FAN), Figure 1 [2,3]. The intermediate-Mg* granulites have been inferred (explicitly or implicitly) to represent mixtures of FAN and MAG or Mg-suite rocks. To test...

متن کامل

Unique Spinel-rich Lithology in Lunar Meteorite Alha81005: Origin and Possible Connection to M Observations of the Farside Highlands

Introduction: The discovery of spinel rich rock on the Earth’s Moon, detected by the M near-IR mapping spectrometer on the Chandrayaan-1 spacecraft [1] is among the most intriguing discoveries in a time filled with lunar revelations (e.g., [2]). The M spectrometer discerned several areas on the rim of the far-side Moscoviense basin which had near-IR reflectance spectra characteristic of abundan...

متن کامل

MAC88105-A regolith breccia from the lunar highlands: Miner~o~c~ petrological, and geochemical studies*

The new large Iunar meteorite MAC88105 is a dense breccia, with lithic and mineral clasts and fragments set into a welded matrix. It is a regolith breccia which shows some recrystallization and evidence for a late shock event during which anorthositic glass veins were formed. Shock effects (most probably due to the impact ejection from the moon) are present throughout the sample and require a s...

متن کامل

Sampling the Spa Basin: Some Considerations Based on the Apollo Experience

The evolution of the crust and the timing of early impact events is important in the scientific exploration of the Moon [1]. The recent National Research Council decadal study [2] made sampling the deposits of the South Pole-Aitken basin a major priority for planetary exploration. This basin, located on the southern far side, is the largest and oldest multi-ring basin on the Moon and may have e...

متن کامل

Time-of-day–dependent global distribution of lunar surficial water/hydroxyl

A new set of time-of-day-dependent global maps of the lunar near-infrared water/hydroxyl (H2O/OH) absorption band strength near 2.8 to 3.0 μm constructed on the basis of Moon Mineralogy Mapper (M3) data is presented. The analyzed absorption band near 2.8 to 3.0 μm indicates the presence of surficial H2O/OH. To remove the thermal emission component from the M3 reflectance spectra, a reliable and...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2009