Geochemistry and genesis of magmatic PGE-bearing Cu-Ni sulphide deposit in Wadi Bayhan,southeastern Yemen

The Wadi Bayhan mafic-ultramafic intrusions associated with magmatic PGE-bearing Cu-Ni sulphide deposit are located in the south margin of the Arabian-Nubian Shield,SW Yemen.The intrusions consist of dunite,olivine-pyroxenite,lherzolite,hornblendite,gabbro and gabbronorite.The dunite and lherzolite are the main host rock for the Cu-Ni ores.The new data of the chemical compositions of the rocks have SiO2(50%-53.6%),Al2O3(0-32%) and MgO(4%-28%),and relatively low TiO2(0-3.2%) and K2O+Na2O(0.04%-5.2%).The geoc...     

Geology and fluid inclusion of Wadi Sharis Neoproterozoic orogenic gold deposits in northwestern Yemen

The Wadi Sharis orogenic gold deposit in northwestern Yemen is related to the fault and shear zones vein at medium depth in the crust in the Neoproterozoic meta-sedimentary and meta-volcanosedimentary succession of greenschist to amphibolite facies metamorphism.Three distinct fluid inclusion types have been identified in the gold-bearing quartz sulphide veins of the deposit:(1) type I:vapour-liquid two-phase(VH2O-LH2O),(2) type II:three-phase CO2(VCO2-LH2O-LCO2) and(3) type III:vapour-rich(LCO2-VCO2) inclus...     

Estimation of information losses on reception of acoustic data by the Aline32D system

The results of determining the relative number of recorded oscillograms for acoustic event intensities of up to 400 1/s in the four-channel Aline32D system for acoustic data reception and processing are presented. Since the internal characteristics of a computer determining the data processing performance are not always available, this problem is solved experimentally. Recommendations concerning the determined working parameters of the Aline32D system are given. This work may be used for the solution of geophysical applied problems.     

Evaluation of stratospheric ozone,temperature, and aerosol profiles from the LOANA lidar in Antarctica

We present an evaluation of observations from the Lidar Ozone and Aerosol for NDACC in Antarctica (LOANA) at the Dumont d’Urville station, Antarctica. This instrument is part of the Network for the Detection of Atmospheric Composition Change (NDACC), and ensures continuity with lidar measurements made since 1989 with the previous instrument at this site. This study is based on the dataset from 2008 to 2009, and comparisons are made with observations from balloon soundings, and from three satellite experiments: Aura/MLS, TIMED/SABER, and CALIOP/CALIPSO. The lidar ozone data are in very good agreement with the balloon sounding data (ECC sensor), revealing a bias of less than 3% between 17 and 34 km. For temperature, the lidar shows a low bias of ?3 K at 20 km when compared with Aura/MLS. Between 30 and 50 km, the bias is less than 2 K. We also present our initial results showing diurnal variations in temperature. The amplitude of these diurnal cycles is on the order of 1 K and is unlikely to account for the temperature biases between LOANA and the reference instruments. Comparisons of total attenuated backscatter reveal good qualitative agreement between LOANA and CALIOP, with differences of less than 30% in the derived optical depth.     

Evidence of recent changes in the local Galactic IMF of stars and substars

This paper calculates the stellar–substellar initial mass function (IMF) based on data from low-luminosity stars and substars. We find the mass spectrum for the stars and substars less than 10 million years in age, and we estimate the low-mass part of the stellar–substellar IMF for 10 million years ago.     

Large-Scale Atmospheric–Oceanic Interaction Regimes in the Norwegian and Barents Seas

Doklady Earth Sciences - Large-scale atmosphere–ocean interaction in the Atlantic sector of the Arctic Ocean is analyzed. New studies demonstrate that the variability of Atlantic water inflow...     

Internal Waves of Mode 2 in the Black Sea

Doklady Earth Sciences - The results of the first observations of mode 2 internal waves in the Black Sea are presented. The measurements were carried out on the Crimean shelf from the MGI platform...     

Current trends of ice coverage changes in the Franz Josef Land Archipelago area

Doklady Earth Sciences - The data on the ice distribution in the Franz Josef Land Archipelago area during the 2010/2011 and 2014/2015 ice seasons depending on climate oscillations are presented...     

Geographical factors of the abundance of flora in Russian cities

Doklady Earth Sciences - An analysis of data on the species abundance of flora in 89 cities (urban flora) of the Russian Federation facilitated determination of its main factors. It has been...