Results 141 to 150 of about 30,947 (278)

Mantle dynamics and petrogenesis of Gomer basalts in the Northwestern Ethiopia: A geochemical perspective

open access: yesOpen Geosciences
This study investigates the petrological and geochemical characteristics of basalts from the Gomer area in the Northwestern Ethiopian Volcanic Province to explore their petrogenesis and mantle source characteristics.
Wondem Habtamu   +3 more
doaj   +1 more source

Talc‐Tempered Pottery From Bala Hissar, Kabul: An Analytical Study

open access: yesArchaeometry, EarlyView.
ABSTRACT Potsherds of cooking ware excavated at Bala Hissar archaeological site in Kabul were studied using X‐ray fluorescence (XRF), scanning electron microscope‐energy dispersive X‐ray spectrometry (SEM‐EDS), Raman spectroscopy, X‐ray powder diffraction (XRPD), thermogravimetric analysis (TGA) and optical microscopy.
Parviz Holakooei   +4 more
wiley   +1 more source

An Experimental Approach on Pearl Shell (Pinctada margaritifera) for a Microwear Study of Shell Artefacts From French Polynesia

open access: yesArchaeometry, EarlyView.
ABSTRACT Pinctada margaritifera (black‐lipped pearl oyster) artefacts are ubiquitous in the archaeological record throughout the Pacific and particularly in Polynesia. Despite efforts towards the development of typologies, the lack of microwear and use‐wear studies has prevented the development of technological approaches. We used 20 pearl shell valves
Jemma McGloin   +2 more
wiley   +1 more source

Exploring Use‐Wear Texture Quantification Through Confocal Microscopy on Tools Made From Volcanic Rocks (Basalt and Phonolite)

open access: yesArchaeometry, EarlyView.
ABSTRACT Functional analysis is essential for reconstructing lithic tool use. Recent approaches combining confocal microscopy and surface texture analysis provide quantitative alternatives to traditional visual use‐wear analysis, although their application to coarse‐grained, heterogeneous rocks remains challenging because of their complex surface ...
Idaira Brito‐Abrante   +2 more
wiley   +1 more source

Influence of Laser Repetition Rate, Fluence and Spot Size on LA‐Q‐ICP‐MS/MS 87Sr/86Sr Precision: Insights from Apatites and Silicate Glasses

open access: yesGeostandards and Geoanalytical Research, EarlyView.
Key Points Higher laser repetition rate, fluence and larger spot size increase signal intensity. Higher laser repetition rate produces overlaps in aerosolised particles, improving signal stability and precision. For Sr‐rich materials, moderate spot diameter (≤ 60 μm), 3 J cm‐2 fluence and ≥ 12 Hz repetition rate are recommended.
Edafe O. Ominigbo   +4 more
wiley   +1 more source

Quantification of Sulfur Speciation in Apatites: Comparison of the XAS, XPS and EPMA Techniques

open access: yesGeostandards and Geoanalytical Research, EarlyView.
Key Points Sulfur speciation in apatites has been determined by S K‐edge X‐ray absorption near‐edge structure (XANES) spectroscopy, S 2p X‐ray photoelectron spectroscopy (XPS) and electron probe microanalysis (EPMA). XANES provides the most sensitive and accurate quantification of sulfur speciation.
Yuzhou Feng   +8 more
wiley   +1 more source

Declining habitat directive butterflies within a major stronghold: Challenges for conservation Rückläufige Tagfalter der FFH‐Richtlinie in einer bedeutenden Hochburg: Herausforderungen für den Naturschutz

open access: yesInsect Conservation and Diversity, EarlyView.
Myrmecophilous Phengaris nausithous and P. teleius are highly specialized grassland butterflies and flagship species for European nature conservation, but they exhibit ongoing population declines. We show strong declines for both species in the Westerwald mountain range, western Germany, since 1994, driven by inappropriate timing of mowing, grassland ...
Klaus Fischer   +10 more
wiley   +1 more source

Processes and Patterns of Dolomite Precipitation in Aptian Pre‐Salt Deposits of Santos Basin, Brazil

open access: yesJournal of Petroleum Geology, EarlyView.
ABSTRACT The Aptian pre‐salt lacustrine carbonates represent the most significant oil exploration target along the South Atlantic margin. Dolomitization of the Santos Basin Barra Velha Formation (BVF) is critical for reservoir quality, yet its origin, patterns, and evolution remain poorly understood.
J. T. F. Oste   +3 more
wiley   +1 more source

California's vernal‐pool mousetails (Myosurus, Ranunculaceae): Phylogenetic analysis of ddRADseq data, hybridization tests, and species delimitation

open access: yesJournal of Systematics and Evolution, EarlyView.
We present the first phylogenetic analysis of the Californian species of Myosurus. Our ddRADseq analysis reveals considerably more diversity than what was recognized in recent floristic treatments. Myosurus minimus subsp. apus was found to be a rare species restricted to Southern California and northwestern Baja California.
R. Douglas Stone   +2 more
wiley   +1 more source

Distinct chalcophile-element inheritance from subducted continental crust in metasomatized mantle. [PDF]

open access: yesSci Adv
Wang Z   +13 more
europepmc   +1 more source

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