Results 71 to 80 of about 14,747 (240)

Structural analysis and metamorphism of Palaeoproterozoic metapelites in the Seinäjoki-Ilmajoki area, western Finland [PDF]

Bulletin of the Geological Society of Finland, 1999
The Palaeoproterozoic Svecofennian bedrock of the Seinäjoki-Ilmajoki area, western Finland, is largely composed of porphyroblastic metapelites. In the area, the regional metamorphic grade increases towards the southwest.
H. Mäkitie
doaj   +1 more source

Coesite Discovery in Eclogites Confirms UHP Metamorphism in the Orlica‐Śnieżnik Dome (SW Poland)

Journal of Metamorphic Geology, EarlyView.
ABSTRACT Eclogite lenses are exposed within the orthogneiss‐dominated core of the Orlica‐Śnieżnik Dome in the Sudetes, which forms the northeastern margin of the Bohemian Massif (Variscan Belt of Central Europe). The presence of coesite inclusions in garnet and omphacite confirms that these eclogites underwent ultrahigh‐pressure metamorphism.
Małgorzata Nowak, Lucie Tajčmanová, Marcin Dąbrowski, Iris Buisman, Jacek Szczepański   +4 more
wiley   +1 more source

Location, Location, Location: Monazite Behaviour During UHT Metamorphism and Melt Crystallization

Journal of Metamorphic Geology, EarlyView.
ABSTRACT Monazite is a robust mineral for recording the suprasolidus evolution of migmatites and granulites. However, monazite commonly has diverse compositions and yields variable dates in a single sample; understanding the controls on monazite behaviour and composition during partial melting and melt crystallization are not always straightforward ...
Chris Yakymchuk, Jessica Gareau, Michael Williams   +2 more
wiley   +1 more source

La terra dove nulla scompare per sempre [PDF]

Kaiak, 2015
The traditional cultures of Native American tribes and populations have been humbled for a very long time by the WASP dominant vision of the US destiny. Through particular laws like the sadly well-known Indian Removal Act (1830), the
Giuseppe Russo
doaj  

Decoding Metamorphic Nanodiamonds Formation Through Their Internal Structures

Journal of Metamorphic Geology, EarlyView.
ABSTRACT Metamorphic diamonds offer insights into Earth's evolution, modulating the global carbon cycle through subduction into the mantle and exhumation. However, the formation and internal structure of minute diamonds remain poorly understood. Here, we study the internal structures of diamond‐bearing inclusions from the Eastern Alps using state‐of ...
Tim Sotelšek, Marian Janák, Sašo Šturm, Sorour Semsari Parapari, Nik Gračanin, Kristian Radan, Mehmet Ali Gülgün, Stanislava Milovská, Mirijam Vrabec   +8 more
wiley   +1 more source

Noble gases and nitrogen in material from asteroid Bennu

Meteoritics &Planetary Science, EarlyView.
Abstract We report the elemental and isotopic abundances of all stable noble gases (helium, neon, argon, krypton, and xenon) in eight particles from asteroid Bennu returned by NASA's OSIRIS‐REx mission. We also report nitrogen abundances and isotopic ratios that were analyzed alongside neon and argon in four additional Bennu particles.
B. Marty, L. Zimmermann, E. Füri, D. V. Bekaert, J. J. Barnes, A. N. Nguyen, H. C. Connolly, D. S. Lauretta   +7 more
wiley   +1 more source

Olivine-chrome-spinel equilibrium in chromitites and ultramafites of Rai-Iz massif, Polar Urals

Литосфера, 2016
Olivine and chrome-spinel compositions from chromitites and ore-bearing metamorphosed ultramafic rocks of Rai-Iz massif were compared. It was established that olivine and spinel ferruginosity are directly proportional and increase monotonically from ...
P. B. Shirjaev, N. V. Vakhrusheva
doaj   +2 more sources

Implications of Surface Heat Flux for Shear Stress and Temperature on the Plate Interface Beneath Northern Honshu

Geochemistry, Geophysics, Geosystems
Measurements of surface heat flux from boreholes of the NIED Hi‐net network of seismometers are used to determine temperature and shear stress on the plate interface beneath northern Honshu.
Philip England, Takumi Matsumoto, Simon Wallis   +2 more
doaj   +1 more source

Determining impact angle from the spatial distribution of shock metamorphism: A case study of the Gosses Bluff (Tnorala) impact structure, Australia

Meteoritics &Planetary Science, EarlyView.
Abstract The majority of planetary impacts occur at oblique angles. Impact structures on Earth are commonly eroded or buried, rendering the identification of the direction and angle of impact—using methods such as asymmetries in ejecta distribution, surface topographic expression, central uplift structure, and geophysical anomalies—challenging. In this
Eloise E. Matthews, Auriol S. P. Rae, Thomas Kenkmann, Nicholas E. Timms, Aaron J. Cavosie, Marian B. Holness   +5 more
wiley   +1 more source

Vertical profiling of shock attenuation at the Rochechouart impact structure, France

Meteoritics &Planetary Science, EarlyView.
Abstract Rochechouart, south‐west France, is a complex impact structure. Here, we present the first report of shock barometry of quartz from what are likely parautochthonous basement units at depth, based on samples from the 2017 C.I.R.I.R drilling campaign. The crystallographic orientations of 725 sets of PDFs in 512 quartz grains in samples from four
P. Struzynska, S. Alwmark, C. Alwmark, M. H. Poelchau, P. Lambert   +4 more
wiley   +1 more source