Browsing ELibrary by Title
- DSpace Home
- →
- Геология России
- →
- ELibrary
- →
- Browsing ELibrary by Title
JavaScript is disabled for your browser. Some features of this site may not work without it.
Browsing ELibrary by Title
Now showing items 8566-8585 of 21768
-
(1999)Oxygen isotope compositions of individual mineral grains in two spinel-bearing chondrules have been determined by secondary ion mass spectrometry. O isotope ratios of spinel grains in a plagioclase-rich chondrule were ...
-
(2004)Oxygen isotope exchange between minerals during metamorphism can occur in either the presence or the absence of aqueous fluids. Oxygen isotope partitioning among minerals and fluid is governed by both chemical and isotopic ...
-
(1999)Oxygen isotope fractionations have been measured experimentally between dissolved orthophosphate ions H2PO4- and water from 50°C to 135°C. The derived equilibrium fractionation equation reveals that biogenic apatites are ...
-
(2004)Oxygen isotope exchange between H2O and H4SiO4 was modeled with ab initio calculations on H4SiO4 + 7H2O. Constrained optimizations were performed with the B3LYP/6–31+G(d,p) method to determine reactants, transition states, ...
-
(1999)Oxygen isotope exchange between calcite and forsterite were investigated in the presence of a large amount of supercritical fluid. The experiments were conducted in standard cold-seal pressure vessels at 680°C and 500 MPa ...
-
(1999)Oxygen isotope fractionations in laboratory systems have been determined between chlorite and water at 170-350°C. In one series of experiments, the Northrop-Clayton partial exchange method was used where three (sometimes ...
-
OXYGEN ISOTOPE FRACTIONATION BETWEEN DIATOMACEOUS SILICA AND WATER - IMPLICATIONS AND APPLICATIONS (1998)The temperature dependence of the oxygen isotope fractionation between diatomaceous silica and water was determined by analyzing frustules of freshwater diatoms cultured in the laboratory at temperatures ranging from 3.6 ...
-
(2002)Oxygen isotope fractionation between synthesised zircon and water has been experimentally quantified at 700, 800, 900, and 1000°C. The results are interpolated by: Delta(zrn-H2O) = -3.70 + 2.74 +/- 0.19 x(2), where x = ...
-
(2005)Hydrous CaMg-carbonate was synthesized at temperatures of 40°, 60° and 80°C in the laboratory. This material has very similar mineralogical characteristics to natural disordered dolomite from the Coorong region in South ...
-
(1999)The magnitude and temperature-sensitivity of oxygen isotope fractionation in ferric oxide-water systems remain uncertain. In this study, three different synthetic methods are used to investigate the temperature dependence ...
-
(1995)The modified increment method is applied to the calculation of oxygen isotope fractionation in different structures of magnetite. The results show that, at isotopic equilibrium, the magnetite of a spinel-type structure has ...
-
(2004)Mg-bearing calcite was precipitated at 25°C in closed system free-drift experiments from solutions containing NaHCO3, CaCl2 and MgCl2. The chemical and isotope composition of the solution and precipitate were investigated ...
-
OXYGEN ISOTOPE GEOCHEMISTRY OF THE AMPHIBOLES: ISOTOPE EFFECTS OF CATION SUBSTITUTIONS IN MINERALS (1998)The occurrence of coexisting amphiboles in rocks and the likelihood of concurrent isotope closure allows equilibrium oxygen isotope fractionations among the amphiboles to be recovered from natural samples. Oxygen isotope ...
-
(1998)The occurrence of coexisting amphiboles in rocks and the likelihood of concurrent isotope closure allows equilibrium oxygen isotope fractionations among the amphiboles to be recovered from natural samples. Oxygen isotope ...
-
(2004)We report a study of the oxygen isotope ratios of chondrules and their constituent mineral grains from the Mokoia, oxidized CV3 chondrite. Bulk oxygen isotope ratios of 23 individual chondrules were determined by laser ...
-
(1995)Based upon a compilation and analysis of O-isotope data for Neogene volcanic rocks worldwide, the d18O variation for 743 basalts (historic lavas, submarine glasses, and lavas with 2O) is +2.9 to +11.4‰. Mid-ocean-ridge ...
-
(1998)58 samples of fossil mammoth and reindeer teeth and bones of various ages and coming from different locations were studied for the oxygen isotopic composition of their phosphate. Samples from Siberia have interstadial ...
-
(2003)The influence of NaCl, CaCl2, and dissolved minerals on the oxygen isotope fractionation in mineral-water systems at high pressure and high temperature was studied experimentally. The salt effects of NaCl (up to 37 molal) ...
-
(1999)The carbonaceous chondrites display the widest range of oxygen isotopic composition of any meteorite group, as a consequence of the interaction of primordial isotopic reservoirs in the solar nebula. These isotopic variations ...
-
(1997)New data are reported for the 18O composition of hot hydrothermal fluids from various sites with different tectonic settings. The measured δ18O, in the range 0.53-2.3%% confirm earlier data suggesting that mid-ocean ridge ...
Now showing items 8566-8585 of 21768