Results 81 to 90 of about 5,382 (223)

Potassium isotopic compositions and exposure ages of evolved and silica‐rich achondrites

Meteoritics &Planetary Science, EarlyView.
Abstract Some of the oldest igneous rocks in the Solar System include evolved and silica‐rich achondrites that originate from parent bodies less than 1000 km in diameter, referred to as planetesimals. While Earth was initially in a molten state and required continental crust formation and plate tectonics to generate andesite bulk compositions, evolved ...
Z. Vaci, Z. Tian, P. Koefoed, M. Habermann, M. Humayun, K. Ziegler, H. Busemann, D. Krietsch, J. M. D. Day, K. Wang   +9 more
wiley   +1 more source

Coupled Zircon-Rutile U-Pb Chronology: LA ICP-MS Dating, Geological Significance and Applications to Sediment Provenance in the Eastern Himalayan-Indo-Burman Region

Geosciences, 2019
U-Pb dating by LA ICP-MS is one of the most popular and successful isotopic techniques available to the Earth Sciences to constrain timing and rates of geological processes thanks to its high spatial resolution, good precision (absolute U/Pb age ...
Laura Bracciali
doaj   +1 more source

Characterization of coesite‐bearing impact melt glass from the Hapcheon crater, Korea: Trimodal phase architecture, shock metamorphism, and implications for 40Ar/39Ar geochronology

Meteoritics &Planetary Science, EarlyView.
Abstract We present the first micrometer‐scale, phase‐resolved compositional characterization of impact melt glass from the Hapcheon crater (~1.4 km apparent diameter), the first confirmed impact structure on the Korean Peninsula, integrating EPMA‐WDS (5 μm spot), confocal Raman spectroscopy (<1 μm spot), XRD, and 40Ar/39Ar step‐heating geochronology ...
Jin‐Young Lee, Jeongmin Kim, Sei‐Sun Hong   +2 more
wiley   +1 more source

Zircons and zircon’s geochronology of gabbro Nurali massif (the Southern Urals)

Литосфера, 2018
Object. In the article presents the the results of mineralogy, geochemistry and isotope-chronological investigation of zircons from gabbro Nurali massif. Materials and methods . Amphibole gabbro is the fine-grained and massive texture rock, which cosists
Artur A. Krasnobaev, Petr M. Valizer
doaj   +1 more source

Spatial and temporal evolution of a coastal erg margin: the Middle Jurassic Page Sandstone, southern Utah, USA

Sedimentology, EarlyView.
ABSTRACT Aeolian deflationary events are erosive to static stages where sediment supply is insufficient to support bedform migration and preservation in the rock record. In the vicinity of shallow‐marine environments, inland rises of relative water table and associated generation of deflationary super surfaces may be driven by the onset of ...
Victor J. P. Hême de Lacotte, Chester H. C. Davies, Briony J. Bowler, Stuart M. Clarke, Thomas J. H. Dodd   +4 more
wiley   +1 more source

Testing the fidelity of zircon as a provenance indicator in fluvial‐fan successions: An example from the Palaeogene Colton Formation, Central Utah, USA

The Depositional Record
The stratigraphic, spatial and temporal variability of detrital zircon age populations in continental sedimentary successions is a critical tool in understanding palaeodrainage networks and how these systems distributed detritus within sedimentary basins.
Davide Carraro, Sean P. Gaynor, Dario Ventra, Alexey Ulyanov, Andrea Moscariello   +4 more
doaj   +1 more source

Thermo‐Tectonic History of Archean Basement Rocks in the Aktash Tagh, Southeastern Tarim Craton: Constraints From Zircon U‐Pb, Zircon and Apatite Fission‐Track Dating

Geochemistry, Geophysics, Geosystems
Stable craton lithosphere can undergo complex tectonic events at its margins due to peripheral tectonic activity. In this study, we conducted a comprehensive analysis of zircon U‐Pb dating, apatite and zircon fission‐track thermochronology on the Aktash ...
Xiao Hu, Zhiyuan He, Ganqing Xu, Johan DeGrave, Rongfeng Ge, Guangwei Li, Wenbin Zhu   +6 more
doaj   +1 more source

Fixed Points of Zircon Automorphisms

Order, 2008
A zircon is a poset in which every principal order ideal is finite and equipped with a so-called special matching. We prove that the subposet induced by the fixed points of any automorphism of a zircon is itself a zircon. This provides a natural context in which to view recent results on Bruhat orders on twisted involutions in Coxeter groups.
openaire   +3 more sources

THE PROLONGED INFLUENCE OF ROOT DRESSING OF CAJANDER LARCH (LARIX CAJANDERY MAYR.) ANNUAL AND BIENNIAL SEEDLINGS WITH THE GROWTH STIMULANTS ZIRCON AND EPIN ON THEIR GROWTH AT FIFTEEN YEARS OF AGE

Siberian Journal of Life Sciences and Agriculture
Cajander larch (Larix cajandery Mayr.) is the eastern race of Gmelin larch, the main forest-forming species in the Amur Region and the Primorsky Territory. It is widely used in the national economy. It is promising  for landscaping.
Valentina Yu. Ostroshenko, Lyudmila Yu. Ostroshenko   +1 more
doaj   +1 more source

Zircons from Eclogite-Associated Rocks of the Marun–Keu Complex, the Polar Urals: Trace Elements and U–Pb Dating

Geosciences
The Marun–Keu complex plays a significant role in our understanding of the geological evolution of the Ural orogen; however, it remains poorly understood.
Laysan Salimgaraeva, Aleksey Berezin, Sergey Sergeev, Nikolai Gubanov, Ekaterina Stetskaya, Sergey Skublov   +5 more
doaj   +1 more source