نتایج جستجو برای: geochemical indices
تعداد نتایج: 94781 فیلتر نتایج به سال:
The copper skarn deposit at Gowdal is located in northeast of Shivardagh batholithic body, north of Ahar, East-Azarbaidjan Province. The Shivardagh intrusive body is a part of the magmatic belt of the Alborz-Azarbaidjan-Lesser Caucasus which in turn is related to the magmatic arc of the Meso-Tethys Ocean. The skarn mineralization of copper, iron, and molybdenum (chalcopyrite, pyrite, molybdenit...
Soils are an important site of carbon storage1. Climate is generally regarded as one of the primary controls over soil organic carbon1,2, but there is still uncertainty about the direction and magnitude of carbon responses to climate change. Here we show that geochemistry, too, is an important controlling factor for soil carbon storage.Wemeasured a range of soil and climate variables at 24 site...
A two-dimensional model for virus transport in physically and geochemically heterogeneous subsurface porous media is presented. The model involves solution of the advection-dispersion equation, which additionally considers virus inactivation in the solution, as well as virus removal at the solid matrix surface due to attachment (deposition), release, and inactivation. Two surface inactivation m...
[1] We integrate groundwater geochemistry, mineralogy, and numerical modeling techniques to study the reactive transport of heavy metals and isotopes in the Eutaw coastal plain aquifer, Alabama. Geochemical data show that the elevated concentrations of Fe, Mn, and Sr can be correlated with high pH and alkalinity. These geochemical correlations suggest that that elevated metal concentrations may...
Predicting and controlling the concentrations of redox-sensitive elements are primary concerns for environmental remediation of contaminated sites. These predictions are complicated by dynamic flow processes as hydrologic variability is a governing control on conservative and reactive chemical concentrations. Subsurface heterogeneity in the form of layers and lenses further complicates the flow...
Hanza region is located in the southern part of Urumieh–Dokhtar Metallogenic belt in southeastern Iran. This region includes six known porphyry copper deposits and it is considered as an ore- bearing region from geochemical point of view. The aim of this research is to examine effective processing techniques in the analysis of stream sediment geochemical datasets and ASTER satellite images. The...
maharlu saline lake is located in the sw of iran. to assess the environmental pollution of thelake, the total concentrations of as, cr, co, cu, cd, pb, zn, ni, fe, and mn were determined in the surfacesediments and water of the lake. as and cr were not detected in the water samples, however, the meanconcentrations of other dissolved metals in maharlu lake water were 0.28 mg/l for cu, 0.28 μg/l ...
Oceanic anoxia is considered as the immediate cause of Frasnian–Famennian mass extinction, yet frequency and associated environmental modulators remains unknown. Here, we demonstrate that astronomical forcing paced oceanic anoxic episodes by mediating land-ocean interactions during Upper Kellwasser (UKW) Event, using an ultra-high-resolution (one centimeter spacing), multi-proxy geochemical pro...
the zagreb indices are the oldest graph invariants used in mathematical chemistry to predictthe chemical phenomena. in this paper we define the multiple versions of zagreb indicesbased on degrees of vertices in a given graph and then we compute the first and secondextremal graphs for them.
in an attempt to reconstruct the paleoenvironments of deposition for the middle jurassic baghamshah formation, samples collected from six outcrop sections along the shotori swell were subjected to detailed geochemical analyses. bulk geochemical and biological marker data indicate a logical trend of the variation of organic input, salinity, and oxicity within baghamshah paleoenvironments across ...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید