Results 21 to 30 of about 43,126 (119)

Infrared diffuse reflectance spectra of several thermallymetamorphosed carbonaceous chondrites [PDF]

, 1992
P(論文)Infrared diffuse reflectance spectra (2.53-25μm) were measured for several Antarctic carbonaceous chondrites. Thermally metamorphosed carbonaceous chondrites with CI-CM affinities (Belgica (B)-7904,Yamato (Y)-793321,Y-82162,and Y-86720), which were ...
Miyamoto, Masamichi
core   +1 more source

Origin of volatile element depletion among carbonaceous chondrites

, 2020
Compared to the composition of CI chondrites and the Sun, all other carbonaceous chondrites are variably depleted in volatile elements. However, the origin of these depletions, and how they are related to volatile loss during high-temperature processes ...
Hopp, T., Hellmann, J., Kleine, T., Burkhardt, C.   +3 more
core   +1 more source

Space Weathering Simulation Trends on Carbonaceous Chondrites [PDF]

, 2020
Space weathering on primitive asteroids is an ongoing area of research. Primitive asteroids have low geometric albedo (= 0.15) and mostly featureless visible spectra (~0.5 - 0.9 µm) (Campins et al. 2018).
Malfavon, Andrew
core  

Geochemistry and Geochronology of Magmatic Rocks in Southwestern and Northeastern Cambodia: Implications for the Tectonic Evolution and Metallogenesis of the Loei Fold Belt

Geological Journal, EarlyView.
The composition of intrusive rocks suggests that the magma was likely generated in a subduction‐related setting. The arc crustal thickness in the Phnom Sro Ngam and Halo Prospects was probably < 40 km during emplacement. Zircon U–Pb age range indicates a correlation with Loei Fold Belt magmatic activity.
Sirisokha Seang, Khin Zaw, Kakda Kret, Ivan Belousov, Kotaro Yonezu, Koichiro Watanabe, Charles Makoundi   +6 more
wiley   +1 more source

Late Pleistocene Volcanic Rocks From Tengchong Volcanic Field at SE Tibetan Plateau: Constraints on Petrogenesis and Mantle and Crustal Processes

Geological Journal, EarlyView.
Early zircon saturation and crystallisation occur in mafic (52–54 wt.% SiO2) lavas at Tengchong volcanic field. These early formed zircons with high δ18O (6.6‰–7.9‰) indicates mantle enrichment by subducted supracrustal materials. ABSTRACT Late Pleistocene (< 0.2 Ma) mafic and evolved volcanic rocks occur in northern Tengchong Volcanic Field, SE ...
Lizhu Wang, Haibo Zou
wiley   +1 more source

Apatite in Carbonatite Preserving Primary Magmatic, Post‐Magmatic Overgrowth, and Post India‐Asia Collision‐Related Hydrothermal Alteration: Evidenced From U–Pb Isotope and Trace Element Geochemistry

Geological Journal, EarlyView.
U–Pb isotope and trace element geochemistry of apatite from carbonatites of Peshawar Plain Alkaline Igneous Province, western Himalaya shows Permo‐Carboniferous magmatism, an additional magmatic pulse during Cretaceous, and post‐magmatic hydrothermal/metasomatism during Oligocene. ABSTRACT U–Pb isotope and trace element geochemistry of apatite combined
Mehboob ur Rashid, Hafiz U. Rehman, Hao‐Yang Lee, Sun‐Lin Chung, Kaushik Das, Kazumasa Aoki, Muhammad Jawad Zeb, Nasir Ahmad, Muhammad Hussain, Hiroshi Yamamoto   +9 more
wiley   +1 more source

Photochemical effects of Mars‐like UV irradiation on carboxylic acids in carbonaceous chondrites and expectations for abiotic background organics on Mars

Meteoritics &Planetary Science, EarlyView.
Abstract In the search for life on Mars, understanding the origin of preserved organics is critical. Expected sources include exogenous delivery, endogenous synthesis, and potentially life. Environmental processing by ultraviolet (UV) irradiation can alter these organics, obscuring hallmarks of their origin. To deconvolve these effects, we conducted an
D. K. Buckner, J. C. Aponte, A. C. Schuerger, D. I. Foustoukos, F. Seguin, M. B. Wilhelm, G. Cooper, A. J. Williams   +7 more
wiley   +1 more source

Description and terrestrial ages of the Calama Area Meteorite Collection (Atacama Desert, Chile)

Meteoritics &Planetary Science, EarlyView.
Abstract We present a comprehensive study of a meteorite collection from the Atacama Desert (Chile), the driest and most climatically stable desert in the world. This collection includes meteorites from three adjacent Dense Collection Areas (DCAs) in the northern part of the Atacama Desert: Calama, Sierra Gorda, and Chug Chug, referred to as the ...
Carine Sadaka, Jérôme Gattacceca, Florian Dumas, Régis Braucher, ASTER Team, Matthieu Gounelle, Dilyara Kuzina, Cyril Lorenz, Alexandre Corgne, Pierre Sempéré   +9 more
wiley   +1 more source

Post‐flight assessment of the OSIRIS‐REx Sample Return Capsule (SRC) for organic and other potential contaminants

Meteoritics &Planetary Science, EarlyView.
Abstract Regolith samples from the carbonaceous asteroid Bennu were stowed and delivered to Earth in the OSIRIS‐REx spacecraft's Sample Return Capsule (SRC). We applied multiple analytical techniques to study the components of the post‐flight SRC, with a focus on assessing the conditions and any contaminants to which the Bennu samples were exposed ...
Scott A. Sandford, Jason P. Dworkin, Kevin Righter, Feargus A. J. Abernethy, Romain Alosius, José C. Aponte, James Ball, Eve L. Berger, Denise K. Buckner, Henner Busemann, Simon J. Clemett, George Cody, Jamie Elsila, Dionysis I. Foustoukos, Ian A. Franchi, Daniel P. Glavin, Monica M. Grady, Heather V. Graham, Philipp R. Heck, Amy E. Hofmann, Yongsong Huang, Bumsoo Kim, Daniela Krietsch, Nicole G. Lunning, Colin Maden, Hannah L. McLain, Angel Mojarro, Michel Nuevo, Philippe Schmitt‐Kopplin, Ewerton Santos, Maria Schönbächler, Christopher J. Snead, Kathie L. Thomas‐Keprta, Alexander B. Verchovsky, Harold C. Connolly Jr., Dante S. Lauretta   +35 more
wiley   +1 more source

Oxygen isotope thermometry and composition of aqueous fluids within the parent body of asteroid (101955) Bennu

Meteoritics &Planetary Science, EarlyView.
Abstract We report on the petrography and oxygen isotopic compositions from in situ analyses of carbonates (Ca‐carbonate, dolomite, and Fe‐rich magnesite), magnetite, and apatite in particles from asteroid Bennu. Using oxygen isotope thermometry of Ca‐carbonate, dolomite, and magnetite, we estimated crystallization temperatures and the oxygen isotopic ...
Gary R. Huss, Kazuhide Nagashima, Elena Dobrică, Alexander N. Krot, Gregory Cane, Zoe E. Wilbur, Timothy J. McCoy, Catherine M. Corrigan, Sara S. Russell, Jessica J. Barnes, Ann N. Nguyen, Harold C. Connolly Jr., Dante S. Lauretta   +12 more
wiley   +1 more source