Boron isotope compositions were measured in kornerupine and tourmaline from lenses consisting primarily of kornerupine, plagioclase corundum. The occur within hornblende-gneiss or along the boundary between this gneiss an amphibolite lens at Akarui Point Lützow-Holm Complex, Prince Olav Coast, East Antarctica. peak metamorphic conditions have been estimated to be ~ 800-900 oC 8-11 kbar. δ11B wh...

Most tectonic models consider that the “Samail subduction zone” was only zone at mid-Cretaceous convergent Arabian margin. We report four new Rb-Sr multimineral isochron ages from high-pressure (HP) rocks and a major shear of uppermost Ruwi-Yiti Unit Saih Hatat window in Oman Mountains NE Arabia. These demand reassessment intraoceanic suprasubduction-zone evolution formed Samail Ophiolite its m...

Robat-e Zengejeh rocks affected by a variety of events began from Precambrian. This research studied preserved effects of the events. Regional metamorphism is the oldest event in this rocks include schist, amphibolite and orthogneiss, that reached up to amphibolite facies. After this regional metamorphism, it seems that mesocratic (624±5Ma) and hololeucocratic granitoides intruded respectively....

Xenoliths of quartz-absent Fe-rich aluminous metapelite are common within the platinum group element-rich mafic ⁄ultramafic magmatic rocks of the Platreef. Relative to well-characterized protoliths, the xenoliths are strongly depleted in K2O and H2O, and have lost a substantial amount of melt (>50 vol.%). Mineral equilibria calculations in the NCKFMASHTO system yield results that are consistent...

High-grade, migmatitic paragneisses (820°C, 8 kbar peak conditions) of the Valhalla metamorphic core complex experienced the retrograde net transfer reaction (ReNTR): garnet + melt + K-feldspar = sillimanite + biotite + plagioclase during cooling and crystallization of the melt, resulting in an increase in the Fe/(Fe + Mg) of both garnet and biotite at their margins. Diffusion profiles generate...

The continental collision between India and Asia has been ongoing since early Eocene time, but the orogenic record is typically dominated by Miocene younger deformation metamorphism that largely overprinted earlier Eocene-Oligocene events. This hinders our understanding of how crustal thickening responds to initial when Himalayan mountains initially rise. advancement spatially precise petrochro...

DOI: 10.17014/ijog.8.1.73-99 Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and electron microprobe analysis (EMPA) techniques were used to determine the mineralogy chemistry of dominant sulphide associated gold deposits at Fairview Gold Mine Barberton Greenstone Belt (BGB). The rocks ore mineral associations indicate mesothermal (orogenic) conditions for deposit. whole...

Abstract Upper amphibolite-facies metamorphism in subduction zone rocks may occur under exceptional tectonic settings. Differentiating competing mechanisms for its occurrence requires carefully integrated, high-resolution thermobarometric and geochronologic studies of mélange with well-defined field relationships. We present new pressure, temperature, age data from the classic Cretaceous Catali...