Metamorphism along the southern margin of the Archean Superior Province has been historically attributed to the Penokean orogeny. A narrow corridor of amphibolite facies rocks north of the main suture does record 1.83–1.80 Ga metamorphic monazite U–Th–Pb ages that mark the culmination of arc accretion. However, subsequent widespread amphibolite facies metamorphism and associated magmatism is re...

During the COUIX of I :50 000 scale regional mapping in the Northern Selkirk Mountains (NTS 082M) various granitic rocks were sampled for U-Pb geochronology. This report presents new U-Pb data, interpreted ages, and the implications of these results for hvo such samples from the Selkirk Allochthon: the Downie Creek otihogneiss, and the Goldstream Pluto”. The Downie Creek orthogneiss consists of...

In this paper, we investigated two originated metamorphosed harzburgites of the metaperidotite complex from the northern part of the Gishaki area. Harzburgite rocks, as main ultramafic complexes of the studied area, were exposed in the scattered location of the area. Despite intensive alterations, harzburgitic units were discriminated using petrography and Raman spectroscopy studies of relict m...

Introduction: Recent detections of phyllosilicate (clay) minerals in ancient terrains [1-3] have revolutionized our understanding of early hydrothermal activity on Mars. The spectral signatures of phyllosili-cates are seen exclusively in Noachian-aged outcrops and not in Hesperian or Amazonian materials [1-3]. Phyllosilicates are inferred to have been widely em-placed during a period of time (t...

Context. An important benchmark for current observational techniques and theoretical modeling of exoplanet atmospheres is the transit of Venus (ToV). Stellar activity and, in particular, convection-related surface structures, potentially cause fluctuations that can affect the transit light curves. Surface convection simulations can help interpreting the ToV as well as other transits outside our...

Abstract The mantle–crust boundary beneath oceanic spreading centres is a major chemical and thermal interface on Earth. Observations in ophiolites reveal that it underlined by dunitic transition zone (DTZ) can reach few hundred meters thickness host abundant chromitite ore bodies. dunites have been deciphered as essentially mantle-derived most ophiolitic massifs; is, reactional residues of int...

The geochemical features of fluorine and its possible sources in the waters hydrothermal ore fields Dnipro-Donetsk avlakogen (DDA) are considered. It was established that formation anomalies occurs due to interaction infiltration zone free water exchange deep formation, which unloaded along zones faults. is substantiated migration determined by type groundwater, degree mineralization, acid-base...

The processes of carbon mobilisation at convergent plate boundaries are hotly debated. Recent findings suggest that release along subduction geothermal gradients may well be more relevant than previously thought; however, it has remained difficult to achieve steady state atmospheric CO2 conditions over geological time scales based on current volatile cycle models. Here, we report meta-ophicarbo...

Abstract Uvite, CaMg 3 (Al 5 Mg)(Si 6 O 18 )(BO ) (OH) (OH), is a new mineral of the tourmaline supergroup. It occurs in Facciatoia quarry, San Piero Campo, Elba Island, Italy (42°45?04.55?N, 10°12?50.89?E) at centre narrow (2–3 cm wide) vein composed aggregates dark brown to black tourmaline, penetrating (magnesite + dolomite)-rich hydrothermally altered metaserpentinite. Crystals are euhedral...