Results 61 to 70 of about 682 (137)
Graphite-bearing polycrystalline olivine and polycrystalline clinopyroxene with submicron to micron grain size were successfully sintered from a single crystal of naturally occurring olivine (Fo88–92Fa12–8: Mg1.76–1.84Fe0.16–0.24SiO4) and a single ...
Yumiko Tsubokawa, Masahiro Ishikawa
doaj +1 more source
Abstract The origin of the compositional dichotomy between high‐Ti and low‐Ti basalts in continental flood basalt provinces remains debated. Most existing studies attribute this dichotomy directly to variations in primitive magma composition to circumvent the complexities of significant evolutionary processes, such as multiphase fractional ...
Zongpeng Yang +6 more
wiley +1 more source
Abstract The presence of minor minerals is a key factor distinguishing meteorite types, as they provide valuable insights into the formation processes, surface conditions, and evolutionary history of their parent bodies. In Martian nakhlites, one of the most distinctive minor phases is iron‐titanium oxides forming characteristic skeletal textures ...
Leire Coloma +5 more
wiley +1 more source
ABSTRACT The processes involved during subduction initiation (SI) remain poorly constrained, in part due to the rarity of geological archives. Ophiolites and their underlying metamorphic soles are thought to form during subduction zone infancy and may thus provide critical constraints. Metamorphic soles are derived from oceanic crust of the lower plate
François Fournier‐Roy +11 more
wiley +1 more source
Clinopyroxene precursors to amphibole sponge in arc crust [PDF]
AbstractThe formation of amphibole cumulates beneath arc volcanoes is a key control on magma geochemistry, and generates a hydrous lower crust. Despite being widely inferred from trace element geochemistry as a major lower crustal phase, amphibole is neither abundant nor common as a phenocryst phase in arc lavas and erupted pyroclasts, prompting some ...
openaire +3 more sources
Ductile Extrusion Triggered by Continental Collision in NE Brazil
ABSTRACT The Borborema Province in northeastern Brazil hosts one of the world's largest strike‐slip shear zone networks, active during the late Neoproterozoic assembly of West Gondwana. Whether these shear zones initiated during active continental collision or as a post‐orogenic response to far‐field stresses remains debated.
L. R. Tesser +6 more
wiley +1 more source
Major and trace elements, including H2O, were determined in garnet and clinopyroxene to constrain the evolution of mantle xenoliths from Diavik, Canada.
Esther Schmädicke +2 more
doaj +1 more source
From Magma to Atmosphere: Halogen Fluxes During Volcanic Eruptions
Abstract Volcanic eruptions release significant quantities of volatile elements into the atmosphere and stratosphere. Plinian eruptions are particularly efficient at dispersing these elements due to their large magma volumes and high eruption columns.
T. d’Augustin +11 more
wiley +1 more source
Comparative compressibility of clinopyroxenes from mantle nodules
The comparative compressibilities of two clinopyroxenes from mantle nodules were determined by single crystal X-ray diffraction with a Merrill-Bassett diamond anvil cell. The analysed crystals show different chemical compositions: PC 135, from a spinel lherzolitic nodule from Pico Cabugi, NE Brazil, has more R3+ (Fe3+ + VIA1 + Ti + Cr) in the Ml site ...
COMODI, Paola +3 more
openaire +3 more sources
Calcium Solubility of Bridgmanite in Subducted Basalt in Earth's Lower Mantle
Abstract The calcium solubility in bridgmanite and the resulting abundance of davemaoite under lower‐mantle pressure‐temperature conditions have been under debate following a recent report of extensive calcium dissolution in bridgmanite. We experimentally investigated the calcium solubility in bridgmanite in a basaltic composition at pressures up to ...
Chengwei Zhang +7 more
wiley +1 more source

