نتایج جستجو برای: ancient gold mining activities
تعداد نتایج: 575299 فیلتر نتایج به سال:
Use of mercury (Hg) for gold-mining in French Guiana (up until 2006) as well as the presence of naturally high background levels in soils, has led to locally high concentrations in soils and sediments. The present study maps the levels of Hg concentrations in river sediments from five main rivers of French Guiana (Approuague River, Comté River, Mana River, Maroni River and Oyapock River) and th...
a comprehensive study on the chemical composition of rainwater was carried out in obuasi, a gold mining town in ghana. rainwater samples were analyzed for major ions (ca2+,mg2+, k+, na+, nh4+, cl-, no3- and so4 2-) and trace metals (fe, al, zn, pb, cr, and cd). the rainwater was typically acidic with a mean ph of 4.76±0.47, which ranged from 4.0 to 5.6. the low ph found in the water suggests t...
In the Valongo Belt, with an extension of about 90 km, located very close to Porto, northern Portugal, dozens ore deposits various metallic minerals and coal were exploited in 19th 20th centuries. One metals most intensely was antimony, or without associated gold mineralization. This research intends verify extent current environmental legacy ancient antimony mining. A typical old mine selected...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید