Compositional diversity at Theophilus Crater: Understanding the geological context of Mg-spinel bearing central peaks

Dhingra, D.; Pieters, C. M.; Boardman, J.; Head, J. W.; Isaacson, P.; Taylor, L. A.

doi:10.1029/2011gl047314

Cited by 61 publications

(42 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Mg-rich lithologies seen at both Moscoviense and Theophilus (Fig. 15) occur as discrete small areas, all within a highly feldspathic matrix Dhingra et al 2011;Lal et al 2012). Furthermore, at the best scale currently available (~140 m), no two mafic crustal lithologies discussed here have yet been detected in a contiguous manner to suggest layering.…”

Section: Layering Within the Lunar Highlands And Mg-suitementioning

confidence: 71%

“…16, red square) has an inferred Mg# > 75, is located within the Procellarum KREEP Terrane (Jolliff et al 2000), and is associated with a localized thorium enhancement on the order of 16.5 ±2.5 ppm . Dhingra et al (2011) identified a distinct Mg-suite mineralogy, possibly a pink spinel anorthosite within the central peak of Theophilus Crater (Fig. 16).…”

Section: Global Distribution Of the Mg-suitementioning

confidence: 99%

See 1 more Smart Citation

Origin of the lunar highlands Mg-suite: An integrated petrology, geochemistry, chronology, and remote sensing perspective

Shearer

Elardo

Petro

et al. 2014

American Mineralogist

136

154

View full text Add to dashboard Cite

The Mg-suite represents an enigmatic episode of lunar highlands magmatism that presumably represents the first stage of crustal building following primordial differentiation. This review examines the mineralogy, geochemistry, petrology, chronology, and the planetary-scale distribution of this suite of highlands plutonic rocks, presents models for their origin, examines petrogenetic relationships to other highlands rocks, and explores the link between this style of magmatism and early stages of lunar differentiation. Of the models considered for the origin of the parent magmas for the Mg-suite, the data best fit a process in which hot (solidus temperature at ≥2 GPa = 1600 to 1800 °C) and less dense (r ~3100 kg/m 3 ) early lunar magma ocean cumulates rise to the base of the crust during cumulate pile overturn. Some decompressional melting would occur, but placing a hot cumulate horizon adjacent to the plagioclase-rich primordial crust and KREEP-rich lithologies (at temperatures of <1300 °C) would result in the hybridization of these divergent primordial lithologies, producing Mg-suite parent magmas. As urKREEP (primeval KREEP) is not the "petrologic driver" of this style of magmatism, outside of the Procellarum KREEP Terrane (PKT), Mg-suite magmas are not required to have a KREEP signature. Evaluation of the chronology of this episode of highlands evolution indicates that Mg-suite magmatism was initiated soon after primordial differentiation (<10 m.y.). Alternatively, the thermal event associated with the mantle overturn may have disrupted the chronometers utilized to date the primordial crust. Petrogenetic relationships between the Mg-suite and other highlands suites (e.g., alkali-suite and magnesian anorthositic granulites) are consistent with both fractional crystallization processes and melting of distinctly different hybrid sources.

show abstract

Section: Layering Within the Lunar Highlands And Mg-suitementioning

confidence: 71%

Section: Global Distribution Of the Mg-suitementioning

confidence: 99%

Origin of the lunar highlands Mg-suite: An integrated petrology, geochemistry, chronology, and remote sensing perspective

Shearer

Elardo

Petro

et al. 2014

American Mineralogist

136

154

View full text Add to dashboard Cite

show abstract

“…These combined technological improvements have allowed the SELENE Spectral Profiler and Multiband Imager (MI) and the Chandrayaan‐1 Moon Mineralogy Mapper (M 3 ) to unambiguously identify Fe‐bearing crystalline plagioclase across the lunar surface based on its unique 1.25 µm absorption band [ Burns , , ; Adams and McCord , ; Adams and Goullaud , ]. Pure crystalline plagioclase has now been identified in widespread locations across the lunar surface: around impact basins, in massifs in the Inner Rook Mountains of Orientale, and in the central peaks, walls, floor, and ejecta of craters [ Matsunaga et al , ; Ohtake et al , ; Pieters et al , ; Dhingra et al , ; Donaldson Hanna et al , ; Yamamoto et al , ; Cheek et al , ]. While previous NIR laboratory studies have suggested that the band depth and center position of the 1.25 µm feature may vary with Fe and An contents [ Bell and Mao , ; Adams and Goullaud , ; Cheek et al , , ], the relationship between NIR spectral properties of plagioclase and its composition (An#) has yet to be quantified.…”

Section: Introductionmentioning

confidence: 99%

“…Lucey [] used a nonlinear radiative transfer technique to illustrate that NIR spectra assumed to be shocked plagioclase from Orientale [ Spudis et al , ] could be modeled with either crystalline anorthite plus npFe 0 or shocked anorthite and get similar spectral results. Thus, to uniquely distinguish shocked plagioclase outcrops from space weathered soils, additional information such as albedo and the geologic context should be explored using high spatial resolution imagery like the Lunar Reconnaissance Orbiter Camera or the Kaguya Terrain Camera [ Dhingra et al , ]. To avoid the ambiguity between shocked versus weathered regions, our study focuses only on regions that clearly exhibit the 1.25 µm absorption band resulting from minor amounts of Fe 2+ in crystalline plagioclase and are unambiguously rich in Fe‐bearing plagioclase.…”

Section: Introductionmentioning

confidence: 99%

Global assessment of pure crystalline plagioclase across the Moon and implications for the evolution of the primary crust

Hanna

Cheek

Pieters

et al. 2014

J. Geophys. Res. Planets

Self Cite

View full text Add to dashboard Cite

Recent advancements in visible to near infrared orbital measurements of the lunar surface have allowed the character and extent of the primary anorthositic crust to be studied at unprecedented spatial and spectral resolutions. Here we assess the lunar primary anorthositic crust in global context using a spectral parameter tool for Moon Mineralogy Mapper data to identify and map Fe-bearing crystalline plagioclase based on its diagnostic 1.25 μm absorption band. This allows plagioclase-dominated rocks, specifically anorthosites, to be unambiguously identified as well as distinguished from lithologies with minor to trace amounts of mafic minerals. Low spatial resolution global mosaics and high spatial resolution individual data strips covering more than 650 targeted craters were analyzed to identify and map the mineralogy of spectrally pure regions as small as~400 m in size. Spectrally, pure plagioclase is identified in approximately 450 targets located across the lunar surface. Diviner thermal infrared (TIR) data are analyzed for 37 of these nearly monomineralic regions in order to understand the compositional variability of plagioclase (An#) in these areas. The average An# for each spectrally pure region is estimated using new laboratory measurements of a well-characterized anorthite (An 96 ) sample. Diviner TIR results suggest that the plagioclase composition across the lunar highlands is relatively uniform, high in calcium content, and consistent with plagioclase compositions found in the ferroan anorthosites (An 94-98 ). Our results confirm that spectrally pure anorthosite is widely distributed across the lunar surface, and most exposures of the ancient anorthositic crust are concentrated in regions of thicker crust surrounding impact basins on the lunar nearside and farside. In addition, the scale of the impact basins and the global nature and distribution of pure plagioclase requires a coherent zone of anorthosite of similar composition in the lunar crust supporting its formation from a single differentiation event like a magma ocean. Our identifications of pure anorthosite combined with the GRAIL crustal thickness model suggest that pure anorthosite is currently observed at a range of crustal thickness values between 9 and 63 km and that the primary anorthositic crust must have been at least 30 km thick.

show abstract

“…The M 3 data with high spectral resolution and wide spectral coverage identified sites showing Mg-spinel anorthosite (devoid of olivines and pyroxenes and having FeO < 5 wt%) along the rings of Moscoviense basin on the far side of the Moon [54]. These were also found in the central peak of Theophilus crater along the ring of Nectaris basin [55,56].…”

Section: Mg-spinel Anorthosite Across the Moonmentioning

confidence: 94%

Active moon: evidences from Chandrayaan-1 and the proposed Indian missions

Bhandari

Srivastava

2014

Geosci. Lett.

View full text Add to dashboard Cite

), Solar Wind Monitor and Synthetic Aperture Radar gave an insight into an active hydrosphere, with several complex processes operating between lunar surface and its environment. These inferences are based on identification of H, OH, H 2 O, CO 2, Ar etc. in the lunar atmosphere. There are indications that several young (~2 to100 Ma) volcanic regions are present on the Moon as shown by integrated studies using Terrain Mapping Camera and M 3 of Chandrayaan-1 and data from other contemporary missions i.e. Kaguya and Lunar Reconnaissance Orbiter. These data establish that Moon has a dynamic and probably still active interior, in contrast to the generally accepted concept of dormant and quiet Moon. Discovery of Mg spinel anorthosites and finding of kilometer sized crystalline anorthosite exposures by M 3 support the formation of global magma ocean on Moon and differentiation early in its evolutionary history. Furthermore, X-ray Spectrometer data showed anorthositic terrain with composition, high in Al, poor in Ca and low in Mg, Fe and Ti in a nearside southern highland region. This mission provided excellent opportunity for multilateral international cooperation and collaboration in instrumentation and observation in which a dozen countries participated and contributed to the success of the mission. The Mars Orbiter Mission, for study of Martian atmosphere and ionosphere was launched on 5th November, 2013 and is already on its way to Mars. This will be followed by Chandrayaan-2, a well equipped Orbiter-Lander-Rover mission. This article summarises a few results obtained by Chandrayaan-1, which changed some of the concepts about Moon's evolutionary history.

show abstract

Compositional diversity at Theophilus Crater: Understanding the geological context of Mg-spinel bearing central peaks

Cited by 61 publications

References 16 publications

Origin of the lunar highlands Mg-suite: An integrated petrology, geochemistry, chronology, and remote sensing perspective

Origin of the lunar highlands Mg-suite: An integrated petrology, geochemistry, chronology, and remote sensing perspective

Global assessment of pure crystalline plagioclase across the Moon and implications for the evolution of the primary crust

Active moon: evidences from Chandrayaan-1 and the proposed Indian missions

Contact Info

Product

Resources

About