Results 91 to 100 of about 33,494 (250)

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

Late Pleistocene Volcanic Rocks From Tengchong Volcanic Field at SE Tibetan Plateau: Constraints on Petrogenesis and Mantle and Crustal Processes

Geological Journal, EarlyView.
Early zircon saturation and crystallisation occur in mafic (52–54 wt.% SiO2) lavas at Tengchong volcanic field. These early formed zircons with high δ18O (6.6‰–7.9‰) indicates mantle enrichment by subducted supracrustal materials. ABSTRACT Late Pleistocene (< 0.2 Ma) mafic and evolved volcanic rocks occur in northern Tengchong Volcanic Field, SE ...
Lizhu Wang, Haibo Zou
wiley   +1 more source

Comparative effects of olivine and sand on KOH-treated clayey soil

Open Geosciences
Improving the strength of clayey soils remains a key concern in geotechnical practice. This study presents a comparative investigation of the effects of olivine waste and sand grains on a clayey soil, both in the absence and presence of potassium ...
Tahir Abdelmaoula Mahamoud, Sert Sedat, Arslan Eylem, Bol Ertan, Özocak Aşkın, Atlı İbrahim   +5 more
doaj   +1 more source

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

Geological 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, Hong Wentao, Xiao Fan, Jin Guodong, Shi Hongyang, Ma Zhiwang, Wu Chen, Xue Yujingyang   +7 more
wiley   +1 more source

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

Contribution of ultrafine particles to alkalinity in a limestone‐treated waterbody

Limnology and Oceanography: Methods, EarlyView.
Abstract While it is well recognized that suspended particles can bias titration‐based total alkalinity (TA), whether addition of minerals for alkalinity enhancement introduces systematic TA artifacts remains poorly quantified. To address this gap, we quantified the contribution of ultrafine particles (< 0.2 μm) to TA titration introduced by limestone (
Teresa G. Schwemmer, Fiona Teevan‐Kamhawi, Hongjie Wang   +2 more
wiley   +1 more source

Olivine zoning and retrograde olivine-orthopyroxene-metal equilibration in H5 and H6 chondrites

, 2006
Electron microprobe studies of several H5 and H6 chondrites reveal that olivine crystals exhibit systematic Fe-Mg zoning near olivine-metal interfaces. Olivine Fa concentrations decrease by up to 2 mol% toward zoned taenite + kamacite particles (formed ...
REISENER, R. J., GOLDSTEIN, J. I., PETAEV, M. I.   +2 more
core   +2 more sources

Fine slab structure and mechanism of deep earthquakes beneath central Japan

Communications Earth & Environment
Deep-focus earthquakes (> 300 km depth) are widely distributed in global subduction zones, but their mechanism is still debated because the fine structure of deep subducting slabs is unclear.
Xinxin Zhang, Guoming Jiang, Dapeng Zhao, Guibin Zhang   +3 more
doaj   +1 more source

Particle‐Scale Mechanics of a Regolith‐Type Soil

International Journal for Numerical and Analytical Methods in Geomechanics, EarlyView.
ABSTRACT The existing studies have reported that the surface of Mars shows the presence of materials having igneous origin, including basalt and regolith‐type coarse soils. These findings are affected by significant uncertainties and, therefore, the selection of simulants for various exploration applications, including surface mobility of rovers ...
Vincenzo Nardelli, Chencheng Wang, Matthew Richard Coop   +2 more
wiley   +1 more source

A recalibration of the garnet-olivine geothermometer and a new geobarometer for garnet peridotites and garnet-olivine-plagioclase-bearing granulites

, 2007
The garnet-olivine Fe-Mg exchange geothermometer and the garnet-olivine-plagioclase geobarometer have been simultaneously calibrated using reversed experimental data based on the model reactions 3Fe2SiO4 + 2Mg3Al2 Si3O12 = 3Mg2SiO4 + 2Fe3Al2Si3O12 and ...
C. M. WU, Zhao, GC, G. C. ZHAO, Wu, CM
core   +1 more source