scholarly journals Using soil geochemistry to investigate gold and base metal distribution and dispersal in the glaciated north of Ireland

Unearthed ◽  
2016 ◽  
pp. 89-100
Author(s):  
Michael Dempster ◽  
Mark Cooper ◽  
Paul Dunlop ◽  
Andreas Scheib
Keyword(s):  
Base Metal ◽  
Metal Distribution ◽  
Soil Geochemistry

scholarly journals Application of Geochemical Technique in Exploration and Evaluation of Copper, Lead and Zinc Resources of Nepal

1993 ◽  
Vol 9 ◽  
Author(s):  
B. M. Jnawali ◽  
K. M. Amatya
Keyword(s):  
Base Metal ◽  
Host Rock ◽  
Mineral Exploration ◽  
Soil Sampling ◽  
Reliable Estimate ◽  
Soil Geochemistry ◽  
Potential Host ◽  
Lead And Zinc ◽  
Copper Lead

Application of Geochemical technique in mineral exploration was used in Nepal during 1975-1985 by the Mineral Exploration Development Board (MEDR). Systematic drainage reconnaissance over 40,000 km2 area resulted in the recognition of a large number of anomalies several of which are related to previously unknown mineralizations. The anomalies were categorized  into  1  to 4   assessed  on  the  basis  of  magnitude,  homogeneity,  area and potential host rock. All anomalies of category 1 and 2 that were investigated by follow-up stream sediment and soil geochemistry of varying stages were finally found to disclose the mineralized sources. In all cases, detailed grid soil sampling results in conjunction with geologic observations enabled to ascertain the location, extent and continuity of sub­ outcropping bedrock source with considerable precision, but it was not possible to make reliable estimate of grade. It has been attempted to evaluate the base metal resource based on the data available of the MEDR work as well as Department of Mines and Geology (DMG) and others. Although no economic deposits have been discovered except Ganesh Himal Zinc Lead, about 20 base metal prospects have been drilled and tonnage and grade proved and estimated. Of these, Kalitar Copper and Wapsa Copper deposits are considered to be of marginal economic grade, while the rest are inventoried a deposits of subeconomic to non-economic grade.

The effect of metamorphism on metal distribution near base metal deposits

1959 ◽  
Vol 54 (5) ◽  
pp. 919-943 ◽  
Author(s):  
Hubert Lloyd Barnes
Keyword(s):  
Base Metal ◽  
Metal Distribution

Sheet silicates as effective carriers of heavy metals in the ophiolitic mine area of Vigonzano (northern Italy)

2001 ◽  
Vol 65 (1) ◽  
pp. 121-132 ◽  
Author(s):  
E. Dinelli ◽  
F. Tateo
Keyword(s):  
Base Metal ◽  
Clay Fraction ◽  
Stream Sediments ◽  
Northern Italy ◽  
Waste Material ◽  
Metal Distribution ◽  
Effective Control ◽  
Material Surface ◽  
Mine Area ◽  
Sheet Silicates

AbstractIn order to assess the role played by sheet silicates in controlling base metal distribution, the mineralogy of the <2 µm fraction of waste material, surface soils, and stream sediments was investigated in the surroundings of a pyrite-chalcopyrite mine area in northern Italy. The results indicate that smectite is very abundant in the <2 µm fraction of the tailings, and it exerts an effective control on the concentrations of Zn, Ni (and Cu). Normal soils and sediments are characterized by interstratified illite-smectite and by lower base metal concentrations. Away from the mine area, smectite decreases in the stream sediments, and chlorite becomes more important in controlling base metal distribution.Ni, Cr, Cu and Co increase with chlorite and talc, but are depleted in the <2 µm fraction compared to coarser fractions in the stream sediments, because the sand–silt fraction of sediments concentrates ophiolitic fragments, variably enriched in ores. A mechanical dispersion of chlorite is probably the controlling factor. Zinc displays a systematic enrichment in the clay fraction of waste material and in the stream sediments but the main mineral carrier is not identified.

Revisiting the passivation of stainless steels and other passive CRAs

2018 ◽  
Vol 106 (1) ◽  
pp. 107 ◽  
Author(s):  
Jean- Louis Crolet
Keyword(s):  
Electrical Conductivity ◽  
Metal Ions ◽  
Base Metal ◽  
Stainless Steels ◽  
Electronic Conductivity ◽  
Transport Processes ◽  
General Knowledge ◽  
Inorganic Polymers ◽  
Faraday Cage

All that was said so far about passivity and passivation was indeed based on electrochemical prejudgments, and all based on unverified postulates. However, due the authors’ fame and for lack of anything better, the great many contradictions were carefully ignored. However, when resuming from raw experimental facts and the present general knowledge, it now appears that passivation always begins by the precipitation of a metallic hydroxide gel. Therefore, all the protectiveness mechanisms already known for porous corrosion layers apply, so that this outstanding protectiveness is indeed governed by the chemistry of transport processes throughout the entrapped water. For Al type passivation, the base metal ions only have deep and complete electronic shells, which precludes any electronic conductivity. Then protectiveness can only arise from gel thickening and densification. For Fe type passivation, an incomplete shell of superficial 3d electrons allows an early metallic or semimetallic conductivity in the gel skeleton, at the onset of the very first perfectly ordered inorganic polymers (- MII-O-MIII-O-)n. Then all depends on the acquisition, maintenance or loss of a sufficient electrical conductivity in this Faraday cage. But for both types of passive layers, all the known features can be explained by the chemistry of transport processes, with neither exception nor contradiction.

Sign in / Sign up

Export Citation Format

Share Document