Results 61 to 70 of about 2,046 (219)

A POTENTIAL EARLY PROTEROZOIC ZIRCON REFERENCE MATERIAL BAI-1-2023 FOR IN SITU U-Pb DATING

open access: yesГеодинамика и тектонофизика
This study presents U-Pb dating results for zircon collected from the beaches of recreation zone "Peschanaya" (Sandy) on Lake Baikal. These beaches are formed exclusively by the erosion of Early Proterozoic rapakivi granites from the Primorsky Complex ...
A. V. Ivanov   +26 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

Surface roughness, stainability, and translucency of an additively manufactured interim resin reinforced with a commercially available ceramic composite concentrate after coffee thermal cycling

open access: yesJournal of Prosthodontics, EarlyView.
Abstract Purpose To compare the surface roughness (Ra), stainability, and translucency of a ceramic composite concentrate‐reinforced interim resin with its corresponding non‐reinforced formulation and with a ceramic‐filled resin indicated for definitive use after coffee thermal cycling.
Mustafa Borga Donmez   +5 more
wiley   +1 more source

Adjustment of CAD–CAM crowns with and without a 3D‐printed model: Comparative study of marginal fit

open access: yesJournal of Prosthodontics, EarlyView.
Abstract Purpose This study evaluated and compared the marginal fit of CAD–CAM zirconia crown copings with and without a 3D‐printed control model. Materials and Methods This prospective in vitro trial involved 30 zirconia crown copings made from the same STL file. These were divided into two groups.
Marwan Al Akkad   +6 more
wiley   +1 more source

Feldspar Albitization With Implications for Reservoir Quality Evolution of Eocene Turbidite Sandstones in Offshore Espírito Santo Basin, Eastern Brazil

open access: yesJournal of Petroleum Geology, EarlyView.
ABSTRACT The diagenetic albitization of plagioclase and K‐feldspar grains is a transformative process that significantly alters sandstone's detrital composition and formation water chemistry, impacting reservoir quality. In this study, Eocene turbidite sandstones from the offshore Espírito Santo Basin, Brazil, were investigated to elucidate the role of
Eveline E. Zambonato   +2 more
wiley   +1 more source

Is there a Grenvillian basement in the Guerrero-Morelos Platform of Mexico?

open access: yesGeologica Acta, 2007
In the Guerrero-Morelos platform (Guerrero State, Mexico) the adakitic rocks of Early Tertiary age contain abundant hornblende-rich tonalite xenoliths. Zircon crystals have been concentrated from both adakites and xenoliths, and dated using in-situ U-Pb ...
G. Levresse   +3 more
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

open access: yesMeteoritics &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   +2 more
wiley   +1 more source

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

open access: yesMeteoritics &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   +9 more
wiley   +1 more source

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

open access: yesSedimentology, 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   +4 more
wiley   +1 more source

Detrital zircon U–Pb ages and Hf isotope analyses of modern and Quaternary sediments in China: A new dataset with preliminary analysis

open access: yesGeoscience Data Journal
Developments of detrital zircon geochronology have resulted in an explosion of publications that report or discuss detrital zircon data. Combined detrital zircon U–Pb ages with Hf isotope analyses from modern and Quaternary sediments have been widely ...
Xiyun Chen   +5 more
doaj   +1 more source

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