Results 41 to 50 of about 3,762 (245)

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

open access: yesGeological 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

Hydrogen isotopic composition of water in CV-type carbonaceous chondrites [PDF]

open access: yes, 2018
International audienceAmong the different groups of carbonaceous chondrites, variable concentrations of hydrous minerals and organic matter are observed that might be related to the time and/or place of formation of their asteroidal parent bodies ...
Marrocchi, Yves, Piani, Laurette
core   +2 more sources

Infrared spectroscopic taxonomy for carbonaceous chondrites from speciation of hydrous components [PDF]

open access: yes, 2005
Mid-infrared absorption spectra for all types of carbonaceous chondrites were obtained in this study to establish a versatile method for spectroscopic classification of carbonaceous chondrites.
Kagi, H.   +3 more
core   +3 more sources

Solar System’s earliest solids as tracers of the accretion region of Ryugu and Ivuna-type carbonaceous chondrites

open access: yesCommunications Earth & Environment
Samples from the carbonaceous asteroid Ryugu and CI (Ivuna-type) chondrites are dominated by low-temperature, aqueously formed secondary minerals, with rare occurrences of anhydrous primary minerals that formed in the high-temperature region of the solar
Noriyuki Kawasaki   +6 more
doaj   +1 more source

Search for Organized Elements in Carbonaceous Chondrites

open access: yesScience, 1962
Acknowledgment is due the New York Academy of Sciences for permission to publish Figs. 2, 4, 5, and 6 in the report "Search for organized elements in carbonaceous chondrites," by E. Anders and F. W. Fitch [ Science 138, 1392 (28 Dec. 1962)].
E, ANDERS, F W, FITCH
openaire   +3 more sources

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

open access: yesGeological 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   +9 more
wiley   +1 more source

Thermal histories of El Médano 300 (EM 300) and Northwest Africa 8155 (NWA 8155): Implications for the diversity of IAB‐ungrouped iron meteorites and their parent bodies

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract This study provides the first petrographic, crystallographic, and chemical comparison between El Médano 300 (EM 300) and Northwest Africa 8155 (NWA 8155), two particular IAB‐ungrouped iron meteorites. Both contain exceptionally large graphite nodules and “flowers”, providing unique insights into carbon behavior in metallic melts and cooling ...
L. Perez   +8 more
wiley   +1 more source

Unique evidence of fluid alteration in the Kakowa (L6) ordinary chondrite

open access: yesScientific Reports, 2022
Meteorites preserve evidence of processes on their parent bodies, including alteration, metamorphism, and shock events. Here we show that the Kakowa (L6) ordinary chondrite (OC) preserves both shock-melt veins and pockets of detrital grains from a ...
I. P. Baziotis   +8 more
doaj   +1 more source

Reassessing the organic carbon budget in the Murchison meteorite through an extraction–recovery mass‐balance approach

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract A substantial fraction of organic carbon in carbonaceous chondrites has long been described as “missing,” reflecting incomplete recovery and limited resolution of operationally defined organic components. Here, we present a quantitative reassessment of the carbon budget in the Murchison meteorite using an integrated extraction–recovery mass ...
Hina Dohi   +2 more
wiley   +1 more source

Visible, near‐, and thermal infrared spectra of asteroid Bennu samples: Relationship to and implications for remote sensing of carbonaceous asteroids

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Remote spectroscopy is used to characterize the mineralogy and infer the history of planetary bodies. Carbonaceous asteroids, such as B‐type (101955) Bennu, represent the earliest stages of planet formation. B types have a blue (negative) spectral slope and comprise <5% of asteroids.
V. E. Hamilton   +32 more
wiley   +1 more source

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