scholarly journals The Identification and Analysis of Gas-Related Volcanic Features within Chang’e-5 Landing Region

2021 ◽  
Vol 13 (19) ◽  
pp. 3879
Author(s):  
Yuan Chen ◽  
Xing Wang ◽  
Jianjun Liu ◽  
Xin Ren ◽  
Hai Huang ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Explosive Eruption ◽  
Morphological Characteristics ◽  
Source Area ◽  
Volcanic Glass ◽  
Volcanic Eruptions ◽  
The Moon ◽  
Volatile Elements ◽  
History Of ◽  
Multiple Missions

Chang’e-5 (CE-5) successfully landed on the young basalts area in the northeastern Oceanus Procellarum on 1 December 2020. Recent studies on the CE-5 landing area have shown that the lack of gas-related volcanic morphology indicates that the volatile elements captured in the interior of the Moon within late-stage magma is relatively low. Typical lunar gas-related volcanic features include dark mantle deposits, volcanic pits, irregular mare patches and so on. Based on orbital images, topography, and spectral data obtained from multiple missions restricted by the morphologic and compositional characteristics of typical volcanic explosive features, this study investigated the morphological characteristics of the volcanic features in detail and found that there are three dark mantle deposits (DMDs) near the source area of Rima Mairan that have unusually low albedo and abnormally high titanium and iron content than those of the surrounding material. Combined with M3 spectral analysis, it is shown that DMDs contain some volcanic glass components, which indicates a gas-rich explosive eruption process. In addition to DMDs, irregular mare patches (IMPs) and a volcanic depression/pit have been recognized in this area, both of which indicate a history of gas-related volcanic eruptions. Based on this study and combined with past studies, we determined the volcanic history in the source area of Rima Mairan, including both effusive and explosive volcanic activities.

Constitution of terrestrial planets

1981 ◽  
Vol 303 (1477) ◽  
pp. 287-302 ◽  
Keyword(s):  
Bulk Composition ◽  
Parent Body ◽  
The Moon ◽  
Volatile Elements ◽  
Earth’S Mantle ◽  
The Earth ◽  
History Of ◽  
Relationship Of ◽  
Reduced State

Reliable estimates of the bulk composition are so far restricted to the three planetary objects from which we have samples for laboratory investigation, i.e. the Earth, the Moon and the eucrite parent asteroid. The last, the parent body of the eucrite— diogenite family of meteorites, an object that like Earth and Moon underwent magmatic differentiations, seems to have an almost chondritic composition except for a considerable depletion of all moderately volatile (Na, K, Rb, F, etc.) and highly volatile (Cl, Br, Cd, Pb, etc.) elements. The Moon is also depleted in moderately volatile and volatile elements compared to carbonaceous chondrites of type 1 (Cl) and also compared to the Earth. Again normalized to Cl and Si the Earth’s mantle and the Moon are slightly enriched in refractory lithophile elements and in magnesium. It might be that this enrichment is fictitious and only due to the normalization to Si and that both Earth’s mantle and Moon are depleted in Si, which partly entered the Earth’s core in metallic form. The striking depletion of the Earth’s mantle for the elements V, Cr and Mn can also be explained by their partial removal into the core. The similar abundances of V, Cr and Mn in the Moon and in the Earth’s mantle indicate the strong genetic relationship of Earth and Moon. Apart from their contents of metallic iron, all siderophile elements, moderately volatile and volatile elements, Earth and Moon are chemically very similar. It might well be that, with these exceptions and that of a varying degree of oxidation, all the inner planets have a similar chemistry. The chemical composition of the Earth’s mantle, for which reliable and accurate data have recently been obtained from the study of ultramafic nodules, yields important information about the accretion history of the Earth and that of the inner planets. It seems that accretion started with highly reduced material, with all Fe as metal and even Si and Cr, V and Mn partly in reduced state, followed by the accretion of more and more oxidized matter.

Early accretional history of the Earth and the Moon-forming event

Lithos ◽  
1993 ◽  
Vol 30 (3-4) ◽  
pp. 207-221 ◽  
Author(s):  
Stuart Ross Taylor
Keyword(s):  
The Moon ◽  
The Earth ◽  
History Of

Provenance of Jurassic sedimentary rocks of south-central Quesnellia, British Columbia: implications for paleogeography

2004 ◽  
Vol 41 (1) ◽  
pp. 103-125 ◽  
Author(s):  
Nathan T Petersen ◽  
Paul L Smith ◽  
James K Mortensen ◽  
Robert A Creaser ◽  
Howard W Tipper
Keyword(s):  
Detrital Zircon ◽  
Middle Jurassic ◽  
Sedimentary Rocks ◽  
Source Area ◽  
Lower Jurassic ◽  
Early Jurassic ◽  
Late Triassic ◽  
Nd Isotopes ◽  
South Central ◽  
History Of

Jurassic sedimentary rocks of southern to central Quesnellia record the history of the Quesnellian magmatic arc and reflect increasing continental influence throughout the Jurassic history of the terrane. Standard petrographic point counts, geochemistry, Sm–Nd isotopes and detrital zircon geochronology, were employed to study provenance of rocks obtained from three areas of the terrane. Lower Jurassic sedimentary rocks, classified by inferred proximity to their source areas as proximal or proximal basin are derived from an arc source area. Sandstones of this age are immature. The rocks are geochemically and isotopically primitive. Detrital zircon populations, based on a limited number of analyses, have homogeneous Late Triassic or Early Jurassic ages, reflecting local derivation from Quesnellian arc sources. Middle Jurassic proximal and proximal basin sedimentary rocks show a trend toward more evolved mature sediments and evolved geochemical characteristics. The sandstones show a change to more mature grain components when compared with Lower Jurassic sedimentary rocks. There is a decrease in εNdT values of the sedimentary rocks and Proterozoic detrital zircon grains are present. This change is probably due to a combination of two factors: (1) pre-Middle Jurassic erosion of the Late Triassic – Early Jurassic arc of Quesnellia, making it a less dominant source, and (2) the increase in importance of the eastern parts of Quesnellia and the pericratonic terranes, such as Kootenay Terrane, both with characteristically more evolved isotopic values. Basin shale environments throughout the Jurassic show continental influence that is reflected in the evolved geochemistry and Sm–Nd isotopes of the sedimentary rocks. The data suggest southern Quesnellia received material from the North American continent throughout the Jurassic but that this continental influence was diluted by proximal arc sources in the rocks of proximal derivation. The presence of continent-derived material in the distal sedimentary rocks of this study suggests that southern Quesnellia is comparable to known pericratonic terranes.

A Brief History of the Moon

1972 ◽  
Vol 24 (3) ◽  
pp. 72
Author(s):  
John Skoyles
Keyword(s):  
The Moon ◽  
History Of

The history of the core dynamos of Mars and the Moon inferred from their crustal magnetization: a brief review

2019 ◽  
Vol 56 (9) ◽  
pp. 917-931
Author(s):  
Jafar Arkani-Hamed
Keyword(s):  
The Moon ◽  
Positive Mass ◽  
Polar Wander ◽  
The Core ◽  
True Polar Wander ◽  
History Of ◽  
Giant Impacts ◽  
Crustal Magnetization ◽  
Multiple Impact ◽  
Thermochemical Convection

The core dynamos of Mars and the Moon have distinctly different histories. Mars had no core dynamo at the end of accretion. It took ∼100 Myr for the core to create a strong dynamo that magnetized the martian crust. Giant impacts during 4.2–4.0 Ga crippled the core dynamo intermittently until a thick stagnant lithosphere developed on the surface and reduced the heat flux at the core–mantle boundary, killing the dynamo at ∼3.8 Ga. On the other hand, the Moon had a strong core dynamo at the end of accretion that lasted ∼100 Myr and magnetized its primordial crust. Either precession of the core or thermochemical convection in the mantle or chemical convection in the core created a strong core dynamo that magnetized the sources of the isolated magnetic anomalies in later times. Mars and the Moon indicate dynamo reversals and true polar wander. The polar wander of the Moon is easier to explain compared to that of Mars. It was initiated by the mass deficiency at South Pole Aitken basin, which moved the basin southward by ∼68° relative to the dipole axis of the core field. The formation of mascon maria at later times introduced positive mass anomalies at the surface, forcing the Moon to make an additional ∼52° degree polar wander. Interaction of multiple impact shock waves with the dynamo, the abrupt angular momentum transfer to the mantle by the impactors, and the global overturn of the core after each impact were probably the factors causing the dynamo reversal.

The Mausoleum of Youth: Between Experience and Nihilism in Benjamin's Berlin Childhood

Paragraph ◽  
2009 ◽  
Vol 32 (3) ◽  
pp. 313-330 ◽  
Author(s):  
Michael W. Jennings
Keyword(s):  
Human Experience ◽  
The Moon ◽  
History Of Photography ◽  
Work Of Art ◽  
Modern Media ◽  
Siegfried Kracauer ◽  
History Of ◽  
The Relationship

Key sections of Walter Benjamin's montage-text Berlin Childhood around 1900 figure the relationship between human experience and modern media, with the sections that frame the text, ‘Loggias’ and ‘The Moon’, structured around metaphors of photography. Drawing on the work of Siegfried Kracauer, and especially his seminal essay ‘Photography’, Benjamin develops, in the course of his book, a theory of photography's relationship to experience that runs counter to the better-known theories developed in such essays as ‘Little History of Photography’ and ‘The Work of Art in the Age of its Technological Reproducibility’, theories that are part of the broad currents of technological utopianism and, as such, emphasize photography's transformative potentials. In the Berlin Childhood, Benjamin instead emphasizes photography's role in the mortification and annihilation of meaningful human experience. Photography emerges here as the mausoleum of youth and hope.

INTRODUCTION

2007 ◽  
Vol 18 (1) ◽  
pp. 107-108 ◽  
Author(s):  
William R. Fowler
Keyword(s):  
Urban Landscape ◽  
Special Section ◽  
Third Century ◽  
The Sun ◽  
Urban Archaeology ◽  
The Moon ◽  
History Of ◽  
The Temple

This is the twenty-fifth Special Section published in Ancient Mesoamerica, and therefore it represents something of a milestone in the history of the journal. The goal has been to present in each special section a collection of related papers from a single project or region or on a selected topic to provide readers a tightly integrated summary of current research and interpretations. Certainly one of the most compelling and provocative special sections we have published was “Urban Archaeology at Teotihuacan” which appeared in vol. 2, no. 1 (1991). This collection of papers featured two stunning articles on the Feathered Serpent Pyramid, then often referred to as the Temple of Quetzalcoatl. Constructed in the early third century A.D., the Feathered Serpent Pyramid, along with the Sun Pyramid and the Moon Pyramid, was one of the three most powerful monuments in the sacred urban landscape of Teotihuacan. Rubén Cabrera Castro, Saburo Sugiyama, and George L. Cowgill (1991) reported on excavations in the 1980s of the Feathered Serpent Pyramid and the investigation of more than 137 sacrificial burials, including more than 70 males identified as soldiers because of associated offerings, discovered at the base of and underneath the pyramid. In the second article, Alfredo López Austin, Leonardo López Luján, and Saburo Sugiyama (1991) presented their brilliant iconographic analysis of the sculptural facades of the Feathered Serpent Pyramid, arguing that the monumental structure was dedicated to the myth of the origin of time and calendric succession, a tangible cosmogonic proclamation that Teotihuacan was “the place where time began.”

scholarly journals How Bovine Livestock Affects Seed Rain in Subtropical Climate Forest

2019 ◽  
Vol 11 (10) ◽  
pp. 240
Author(s):  
Maureen de Moraes Stefanello ◽  
Ana Paula Moreira Rovedder ◽  
Roselene Marostega Felker ◽  
Matheus Degrandi Gazzola ◽  
Betina Camargo ◽  
...  
Keyword(s):  
Diversity Index ◽  
Morphological Characteristics ◽  
Floristic Composition ◽  
Seed Rain ◽  
Subtropical Climate ◽  
Floristic Similarity ◽  
Management Regime ◽  
Pampa Biome ◽  
Forest Remnants ◽  
History Of

Seed rainfall may be one of the mechanisms most impacted by livestock production in forest remnants. The trampling and cattle grazing alter dynamics, structure and floristic composition of the forest. The present work characterized the seed rainin forest remnants and the possible impacts of the presence and the management regime with different cattle stocks in the Pampa biome, southern region of Brazil. We compared three areas in Seasonal Forest remnants with a management history of 43 years: cattle exclusion area (A1); area with a cattle stock of 0.5 ua ha-1 (A2); and area with cattle stock of 1.0 ua ha-1 (A3). The seed rain was collected quarterly in 16 collectors (1 × 1 m²) per area for 24 months. The seeds were counted and identified according to external morphological characteristics, habit and dispersion syndrome. Shannon diversity index, submitted to the Hutcheson test, Pielou evenness, expected diversity and floristic similarity were determined. The results indicated that the impacts caused by livestock to seed rain were more significant in A3 where a quantitative reduction in the number of seeds was observed, probably due to the low number of plant individuals that make up the community.

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