Results 81 to 90 of about 25,421 (273)
Journal of Metamorphic Geology, EarlyView.ABSTRACT In the middle to lower continental crust, mineral reactions can play a key role in controlling rheological behaviour by generating fine‐grained, mechanically weak domains. In granulite‐facies rocks from Krossøy (Bergen Arcs, Norway), we document how garnet breakdown produced interconnected networks of orthopyroxene + plagioclase ± spinel that ...
Lorena H. Filiberto +4 more
wiley +1 more source
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
Shock metamorphism in meteorites [PDF]
, 2009 Shock metamorphism resulting from hypervelocity collisions between planetary bodies, is a fundamental processes in the solar system. The term "shock metamorphism" is used to describe all changes in rocks and minerals resulting from the passage of shock ...
Zhidong, Xie
core
, 1994 The Iberian Pyrite Belt is an Upper Paleozoic succession which has been divided into the Phyllite-Quartzite Group, the Volcanic-Sliceous Complex and the Culm Group in ascending order from base to the top. The contacts among them are conformable.
Suzuki, shigeyuki
core +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 +7 more
wiley +1 more source
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 +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 +4 more
wiley +1 more source
, 1998 P(論文)Ultrahigh-temperature (UHT) crustal metamorphism occurs where peak metamorphic temperatures of 900-1100℃ have been attained at pressures in the range 7-13 kbar.
Harley, Simon L.
core
Static recrystallization of shocked calcite in Ries impact breccias
Meteoritics &Planetary Science, EarlyView.Abstract Calcite is prone to chemical and microstructural modifications, especially after having been strained at high stresses and strain rates, as during hypervelocity impact events. These modifications include precipitation from pore fluid as well as replacement of strained volumes by recrystallization. In calcite aggregates of a metagranite breccia
Claudia A. Trepmann +8 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