نتایج جستجو برای: chromite ore deposits

تعداد نتایج: 37749  

1999
Ioannis Konstantinou Kapageridis Bryan Denby G. Hunter

Ore grade estimation is a key aspect in the evaluation of a mineral deposit. In this paper an alternative approach to currently applied methods of ore grade estimation is presented. This alternative approach involves a modular neural network system integrated in a state of the art 3D resource modelling package. The need for a new method of ore grade estimation comes from the difficulties in app...

2006
R. Frei A. Meibom

In an attempt to quantify the extent of geochemical heterogeneity within a restricted and well dated portion of the upper mantle, 27 chromite separates from the 90 My old chromite deposits in the Mayarı́–Baracoa ophiolite belt in eastern Cuba have been investigated for platinum group element (PGE) concentrations and Re–Os isotopic systematics. The samples are characterized by systematically subc...

2010
Michael D. West Jonathan D.A. Clarke

The future exploration of Mars is likely to utilize resources that can be extracted in situ. An overview of the geology of Mars has been presented and several mechanisms that could result in the formation of ore deposits have been identified. These include deposits caused by hydrothermal fluids resulting from volcanic activity, large igneous province formation and impact craters. Surface enrich...

2010
VIJAYAN GURUMURTHY NIKOS E. MASTORAKIS

Orissa accounts for 95 percent of the chromium ore reserves of India. It increases the economic status, but adversely reduces the ecological cover. Chromite mines generate considerable quantity of pollutants containing toxic hexavalent chromium, a known carcinogen, which contaminates 10 to 4000 mg/kg (ppm) of total chromium in air, water and soil environment. Surface water and ground water in S...

Journal: :Science 2009
Andrey Bekker Mark E Barley Marco L Fiorentini Olivier J Rouxel Douglas Rumble Stephen W Beresford

Some of Earth's largest iron-nickel (Fe-Ni) sulfide ore deposits formed during the Archean and early Proterozoic. Establishing the origin of the metals and sulfur in these deposits is critical for understanding their genesis. Here, we present multiple sulfur isotope data implying that the sulfur in Archean komatiite-hosted Fe-Ni sulfide deposits was previously processed through the atmosphere a...

Journal: :زمین شناسی اقتصادی 0
محمدرضا شایسته فر محمد محمدی علی رضایی

the study area is located in the south of kerman province and in the esphandoghe- dolatabad zone. numerous chromite ores were found in the area that has been explored by surface outcrops. with respect to the previous exploration- exploitation works and the absence of the pilot layer, the best option was the boreholes’ drilling was the best choice in order to complete the detailed information. f...

Journal: :journal of tethys 0

pb-zn deposits in the kurdistan region, northern iraq, have occurred mainly as a stratabound and open-space filling ore bodies. they are hosted by dolostone and dolomitic-limestone of platform carbonates. the ore deposits at the studied dure and lefan areas are respectively hosted by kurra chine (upper triassic) and bekhme (upper cretaceous) formations. pyrite, sphalerite and galena are the maj...

Journal: :زمین شناسی اقتصادی 0
رضوان مهوری رضا شمسی پور دهکردی هاشم باقری موسی نقره ئیان محمد علی مکی زاده

kalchoye copper-gold deposit is located about 110 kilometers east of esfahan province and within the eocene volcano sedimentary rocks. sandy tuff and andesite lava are important members of this complex.the form of mineralization in area is vein and veinlet and quartz as the main gangue phase. the main ore minerals are chalcopyrite, chalcocite, galena and weathered minerals such as goethite, iro...

2015
Frank J. Calixto

Attenuation images are obtained from 6287 t-star spectral measurements of P-wave microseismic events in a mine setting. The resulting three-dimensional quality factor (Q) model reveals that most of the study region is characterized by low Q values or high attenuation (Q<25), probably caused by cavities and fractures due to mining activities. Q values between 25 and 50 show a high spatial correl...

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