Results 21 to 30 of about 486 (136)

Petrogenesis and Tectonic Setting of Late Mesozoic Felsic Magmatic Rocks in the Wangmushan Mining District, Northern Fujian, South China

open access: yesGeological Journal, EarlyView.
The rhyolitic ignimbrite and K‐feldspar granite porphyry from the Wangmushan mining district, northern Fujian yield ages of 173.8 ± 0.8 and 102.6 ± 0.4 Ma, respectively. Geochemical data, zircon trace elements, whole‐rock Sr–Nd–Pb isotope data, and zircon Hf isotopic compositions indicate that the rhyolitic ignimbrite originated from partial remelting ...
Wei Shaogang   +7 more
wiley   +1 more source

Size Constraints for the Pre-atmospheric Parent Bodies of Ordinary Chondrites

open access: yesThe Planetary Science Journal
The study of S-complex near-Earth objects (NEOs), the parent bodies of ordinary chondrites, has shown that they are dominated by asteroids with LL chondrite-like compositions. This is surprising because among the three subtypes of ordinary chondrites (H,
Juan A. Sanchez   +9 more
doaj   +1 more source

The Nysa family as the main source of unequilibrated LL ordinary chondrites

open access: yesAstronomy & Astrophysics
Context. The origin of the petrologic diversity observed in ordinary chondrites (OCs), the most common meteorites on Earth, remains debated. Competing models invoke either depth-dependent sampling of a single thermally stratified (‘onion-shell’) parent ...
Marsset M.   +18 more
doaj   +1 more source

Late Quaternary lake filling and drying in northern Australia's largest freshwater lake

open access: yesJournal of Quaternary Science, EarlyView.
ABSTRACT Lake Woods, Jurrkulu, is northern Australia's largest freshwater lake filled today in strong Indo–Australian summer monsoons (IASM) to maximum depths of ~5 m. On the western margins of the lake, two large arcuate ridges occur 20 to 40 m above the lake floor and inset within these are other mid‐elevation lake deposits, such as depositional ...
Tim J. Cohen   +14 more
wiley   +1 more source

An investigation of the 27 July 2018 bolide and meteorite fall over Benenitra, southwestern Madagascar

open access: yesSouth African Journal of Science, 2021
Several dozen stones of an ordinary chondrite meteorite fell in and around the town of Benenitra in southwestern Madagascar during the early evening of 27 July 2018, minutes after a widely observed meteor fireball (bolide) transit and detonation.
Roger L. Gibson   +8 more
doaj   +1 more source

Metamorphic or Igneous Zircon? Classification Through Rare Earth Elements, Machine Learning and Logistic Regression

open access: yesJournal of Metamorphic Geology, EarlyView.
ABSTRACT Zircon is a common, highly refractory accessory mineral found in sedimentary, igneous and metamorphic rocks that forms through various processes (e.g., magmatic, hydrothermal, metamorphic growth and recrystallization). Trace element compositions of detrital zircon have been widely applied to understanding tectonic processes and continental ...
Jarrod M. Burges   +5 more
wiley   +1 more source

Xenoliths in meteorites: Insights into the dynamics of material exchange between asteroids

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract A minor fraction of meteorites contains xenoliths, that is, clasts that were formed on a different parent body than that of the host lithology. The occurrence of xenoliths is direct evidence for the exchange of material between asteroids, including exchanges between asteroids from the carbonaceous (CC) and non‐carbonaceous (NC) reservoirs ...
J. Gattacceca   +17 more
wiley   +1 more source

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

A Microkrystite from the Australasian Tektite/Microtektite Strewn Field

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Microkrystites are glassy impact spherules. They contain primary crystallites carrying information on the physical and chemical conditions prevailing during vaporization, melting, and ejection in large impact cratering events. We report on the geochemistry and mineralogy down to nanometer scale of the first microkrystite (ODP1144A,14) from the
Matteo Del Rio   +4 more
wiley   +1 more source

Water and hydroxyl on asteroid Bennu: Reconciling remote observations with OSIRIS‐REx sample analysis

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract This study investigates the spatial distribution and spectral characteristics of the broad hydration feature near 3 μm across the surface of asteroid (101955) Bennu using OVIRS (OSIRIS‐REx Visible and InfraRed Spectrometer) data. We analyzed multiple global OVIRS data sets obtained at different times throughout the Bennu day, revealing ...
Hannah H. Kaplan   +5 more
wiley   +1 more source

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