Results 101 to 110 of about 73,435 (259)

The Effect of Intracrystalline Water on the Mechanical Properties of Olivine at Room Temperature

Geophysical Research Letters
The effect of small concentrations of intracrystalline water on the strength of olivine is significant at asthenospheric temperatures but is poorly constrained at lower temperatures applicable to the shallow lithosphere.
Kathryn M. Kumamoto, Lars N. Hansen, Thomas Breithaupt, David Wallis, Bo‐Shiuan Li, David E. J. Armstrong, David L. Goldsby, Yang (Will) Li, Jessica M. Warren, Angus J. Wilkinson   +9 more
doaj   +1 more source

Production of arsenical bronze using speiss on the Elephantine Island (Aswan, Egypt) during the Middle Kingdom (Middle Bronze Age) (c.2000–1650 BCE)

Archaeometry, EarlyView.
Abstract This paper presents the first direct evidence of the slags produced during the cementation alloying process of Cu with speiss inside ceramic crucibles, thus representing Cu alloying with As in Middle Kingdom Egypt. The settlement deposits from the Middle Bronze Age were excavated on Elephantine Island, within modern Aswan.
Jiří Kmošek, Martin Odler
wiley   +1 more source

Early Holocene jökulhlaup chronology and deglaciation dynamics in central Iceland

Boreas, EarlyView.
Glacial lake outburst floods (jökulhlaups) have occurred throughout the Quaternary in glaciated regions worldwide. Reconstructing flood chronology yields insight into deglaciation processes, environmental change and the role of extreme events in landscape evolution.
Greta H. Wells, Þorsteinn Sæmundsson, Edwin R. C. Baynes, Timothy Beach, Sheryl Luzzadder‐Beach   +4 more
wiley   +1 more source

Forming Olivine Phenocrysts in Basalt: A 3D Characterization of Growth Rates in Laboratory Experiments

Frontiers in Earth Science, 2019
Our current knowledge of the genesis, ascent, storage, and eruption of mafic magmas is intimately linked with olivine, its primary crystal cargo. Recent claims that phenocryst-size crystals can grow rapidly and non-concentrically are challenging our ...
Adrien J. Mourey, Thomas Shea
doaj   +1 more source

New Magnetite Reference Material for SIMS δ18O Measurements and a Study of Precision and Accuracy Due to Crystal Orientation Effects

Geostandards and Geoanalytical Research, EarlyView.
Key Points A new magnetite reference material (PF21mt) is available for δ18O measurements by SIMS. Reproducibility of measurement results in two laboratories suggest orientation bias of ±2‰ (2s) at 20 keV. Repeatability improves to ±1‰ (2s) when using a 13 keV protocol, suggesting reduced orientation bias. In situ isotope ratio measurements provide the
Michelle Ulrich, Daniela Rubatto, Maria Rosa Scicchitano, Benita Putlitz, Thomas Bovay   +4 more
wiley   +1 more source

Garnet–Clinopyroxene Double‐Layered Coronae in a Metagabbronorite From the High‐Grade Metamorphic Gföhl Unit, Moldanubian Zone

Journal of Metamorphic Geology, EarlyView.
ABSTRACT This study investigates garnet–clinopyroxene double‐layered coronae in a metagabbronorite from the high‐grade metamorphic Gföhl Unit (Bohemian Massif). The coronae formed at the interfaces between relic magmatic orthopyroxene, still preserved in the cores of the coronae, and the plagioclase‐rich rock matrix.
Rene Asenbaum, Tereza Nemeškalová, Martin Racek, Vojtěch Janoušek, Julian Portenkirchner, Rainer Abart   +5 more
wiley   +1 more source

Geoengineering impact of open ocean dissolution of olivine on atmospheric CO2, surface ocean pH and marine biology

Environmental Research Letters, 2013
Ongoing global warming induced by anthropogenic emissions has opened the debate as to whether geoengineering is a ‘quick fix’ option. Here we analyse the intended and unintended effects of one specific geoengineering approach, which is enhanced ...
Peter Köhler, Jesse F Abrams, Christoph Völker, Judith Hauck, Dieter A Wolf-Gladrow   +4 more
doaj   +1 more source

A Tale of Three Galaxies: Deciphering the Infrared Emission of the Spectroscopically Anomalous Galaxies IRAS F10398+1455, IRAS F21013-0739 and SDSS J0808+3948

, 2015
The \textit{Spitzer}/Infrared Spectrograph spectra of three spectroscopically anomalous galaxies (IRAS~F10398+1455, IRAS~F21013-0739 and SDSS~J0808+3948) are modeled in terms of a mixture of warm and cold silicate dust, and warm and cold carbon dust ...
Hao, Lei, Li, Aigen, Nikutta, Robert, Xie, Yanxia   +3 more
core   +1 more source

New knowledge about shock events that affected the L‐chondrite parent body from two heavily shocked L6 meteorite finds

Meteoritics &Planetary Science, EarlyView.
Abstract We report new results from a study of shock‐related features in the L6 ordinary chondrites Northwest Africa (NWA) 4672 and NWA 12841. Our observations confirm the occurrence of eight high‐pressure (HP) minerals in each meteorite, namely, ringwoodite, majorite, akimotoite, wadsleyite, albitic jadeite, lingunite, tuite, and xieite.
I. Baziotis, L. Ferrière, C. Ma, J. Hu, D. Palles, P. D. Asimow   +5 more
wiley   +1 more source

Small‐scale elemental abundance variations in Ryugu particles from touchdown 1

Meteoritics &Planetary Science, EarlyView.
Abstract Ryugu materials closely resemble CI chondrites' mineralogical, chemical, and isotopic compositions; yet minor but resolvable differences in certain elemental abundances are evident. In this study, the bulk chemical compositions of eight individual Ryugu particles (1.5–4.3 mg) from the first touchdown site (TD1) were determined using triple ...
Karina López García, Tetsuya Yokoyama, Ikshu Gautam, Makiko K. Haba, Tsuyoshi Iizuka, Nao Nakanishi, Ryota Fukai   +6 more
wiley   +1 more source