Zinc-lead mineralisation in Ganesh Himal region, central Nepal

Carbonate hosted zinc-lead sulphide mineralisation of economic significance occurs in the Ganesh Himal region, central Nepal. The area lies in between 4,000 m and 4,900 m above msl. The mineralised bodies are situated very close to the Main Central Thrust. The mineralisation occurs in crystalline saccharoidal dolomites within a repetitive sequences of garnetiferous mica schists, quartzites, calcareous schists and amphibolites. These rocks (along with the ore) are folded into an anticlinorium and a tight synclinorium, and have suffered metamorphism of almandine-amphibolite-facies and intense deformation during Himalayan orogeny. Discontinuous bands of graphitic schists occur below the mineralised crystalline dolomites. Confined to a single carbonate stratum, the Ganesh Himal zinc-lead ore appears to be of synsedimentary origin and subsequently suffered from metamorphism. Out of six zinc-lead occurrences, only one at Lari is explored extensively. Detail investigations have confirmed more than 1 million tonnes of ore reserve averaging about 16.4% zinc, 2.5% lead and 32 grammes per tonne silver. The ore is rather simple. It consists of sphalerite, abundant pyrite, subordinate galena and pyrrhotite, and rarely chalcopyrite. X-ray diffractometry suggests possible occurrence of pyrargyrite. Ore texture indicates that the recrystallisation of sulphides took place probably at moderate to high temperature condition. Zinc lead ratio is approximately 6.13:1, with recoverable silver and low cadmium (248 ppm in average). Trace element concentration is rather insignificant. This paper is a synthesis of data on the mineral composition and trace element distribution in the Ganesh Himal zinc-lead ore.

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Trace Element Distribution in Virgin Profiles Representing Four Great Soil Groups

Soil Science Society of America Journal ◽

10.2136/sssaj1955.03615995001900030022x ◽

1955 ◽

Vol 19 (3) ◽

pp. 340-344 ◽

Cited By ~ 28

Author(s):

J. R. Wright ◽

R. Levick ◽

H. J. Atkinson

Keyword(s):

Trace Element ◽

Element Distribution ◽

Trace Element Distribution ◽

Soil Groups

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Methylmercury and Trace Element Distribution in the Organs of Stenella coeruleoalba Dolphins Stranded on the French Mediterranean Coast

Open Environmental Sciences ◽

10.2174/1876325101408010035 ◽

2014 ◽

Vol 8 (1) ◽

pp. 35-48 ◽

Cited By ~ 3

Author(s):

Emmanuel Wafo ◽

Véronique Risoul ◽

Thérèse Schembri ◽

Véronique Lagadec ◽

Frank Dhermain ◽

...

Keyword(s):

Trace Elements ◽

Trace Element ◽

Marine Pollution ◽

Element Distribution ◽

Mediterranean Coast ◽

Trace Element Distribution ◽

Slight Reduction ◽

Stenella Coeruleoalba ◽

Contamination Levels

The main objective of this study was to evaluate the contamination by mercury (Hg), methylmercury (Me-Hg), cadmium (Cd), selenium (Se), zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) in dolphins stranded on the French Mediterranean coast. The distributions of these contaminants in the organs of dolphins have also been studied. Overall, contamination levels varied according to the following sequence: liver > kidney > lung > muscle, except for cadmium (kidney > liver > lung > muscle). Size and sex of animals were also considered. Young dolphins were less impacted with trace elements than adults, except for copper. Among the studied parameters, the most important appeared to be the size of mammals. In addition, in the case of mercury and selenium, the sex of mammals seemed to be also relevant. The correlations between the concentrations of trace elements suggest the existence of detoxification processes. Since 1990s, using dolphins for tracing marine pollution, a slight reduction in the burden of the considered trace elements could be noted.

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