Base Metal Deposits in the Iberian Pyrite Belt

1986 ◽  
pp. 304-324 ◽  
Author(s):  
G. K. Strauss ◽  
K. G. Gray
Keyword(s):  
Base Metal ◽  
Iberian Pyrite Belt

Vectors to ore in replacive VMS deposits of the northern Iberian Pyrite Belt: the case study of Aguas Teñidas deposit

2021 ◽  
Author(s):  
Guillem Gisbert ◽  
Fernando Tornos ◽  
Emma Losantos ◽  
Juan Manuel Pons
Keyword(s):  
Volcanic Rock ◽  
Base Metal ◽  
Geophysical Methods ◽  
Mineral Chemistry ◽  
Mining Area ◽  
Iberian Pyrite Belt ◽  
Major Elements ◽  
The European Union ◽  
Horizon 2020 ◽  
Vms Deposits

<p>Volcanogenic Massive Sulphide (VMS) deposits represent a major source of base, precious and other metals of economic and industrial importance. The Iberian Pyrite Belt (IPB) is an outstanding VMS district located in the SW Iberian Peninsula. It is arguably the largest known accumulation of sulphides on the Earth’s crust, and represents the main mining area in Spain and one of the main zones of base metal production in Europe. As in other mining areas, progressive exhaustion of the most shallow and easily accessible deposits is leading to increasingly complex exploration. In this context, the combined study of the mineral systems and the development of new exploration strategies and technologies based on geophysical methods and vectors to ore play a vital role.</p><p>Vectors to ore have the potential to detect the nearby presence of an ore deposit, and to provide information on its likely location or characteristics. But work on vectors to ore in IPB is far from systematic or complete. Previous works have focused on the study of the larger exhalative shale-hosted deposits of the southern IPB or the giant Rio Tinto deposit, but little attention has been paid to the predominantly volcanic rock hosted replacive deposits of the northern IPB, which, although generally smaller in size compared to southern deposits, typically present higher base metal concentrations.</p><p>In this work we have performed a detailed study of the main vectors to ore currently used in the exploration of VMS systems on a representative volcanic rock hosted replacive VMS deposit located in the northern IPB, the Aguas Teñidas deposit. These have included: mineralized unit identification based on whole rock geochemistry, study of the characteristics and behaviour of whole rock geochemical anomalies around the ore (e.g. alteration-related compositional changes, characteristics and extent of geochemical halos around the deposit), with definition of mineralization-related indicative elements threshold values, application of portable XRF analysis to the detection of the previous vectors, and characterization of major elements trends in mineral chemistry (muscovite, chlorite, carbonate) within and away from the mineralized system.</p><p>Data presented in this work are not only applicable to VMS exploration in the IPB, but on a broader scale they will also contribute to improve our general understating of vectors to ore in replacive-type VMS deposits.</p><p>The authors thank MATSA for providing information and access to drill-cores from Aguas Teñidas deposit. This research has been conducted within the NEXT (New Exploration Technologies) project and has received funding by the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No. 776804.</p>

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.

Brahmi legends on Umayyad Fulus: Interrogating local minting practices and numismatic transculturation in Gandhara (ca. 750 CE)

Afghanistan ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 153-165
Author(s):  
Waleed Ziad
Keyword(s):  
Base Metal ◽  
Late Antiquity ◽  
Eighth Century ◽  
Political Authority ◽  
Unusual Feature ◽  
Complex Relationship ◽  
Contact Zones ◽  
Confessional Identity ◽  
Derivatives Of

This paper concerns a historically significant find of copper derivatives of Umayyad post-reform fulus from Gandhara, probably minted in the mid-eighth century under Turk Shahi sovereignty (c. 667–875). The coins share an unusual feature: two Brahmi aksharas on an Umayyad AE prototype, inversely oriented to a partially-corrupted Arabic legend. These base metal coins represent perhaps the only known caliphal imitative varieties issued by moneyers beyond the eastern limits of Umayyad and Abbasid sovereignty. They have the potential to inform our understanding of the complex relationship between political authority, confessional identity, and coin typology in late antiquity – particularly within early “Hindu”– “Muslim” contact zones. Moreover, they provide invaluable clues into the circulatory regimes of Umayyad coinage.

Peculiarities of electrode and base metal melting in electroslag welding

2019 ◽  
Vol 2019 (3) ◽  
pp. 12-17
Author(s):  
I.I. Lychko ◽  
◽  
K.A. Yushchenko ◽  
S.A. Suprun ◽  
S.M. Kozulin ◽  
...  
Keyword(s):  
Base Metal ◽  
Electroslag Welding ◽  
Metal Melting

A Comparative Study on Microgap of Premade Abutments and Abutments Cast in Base Metal Alloys.

2012 ◽  
pp. 120409100715007
Author(s):  
JAINI J L ◽  
SREEKANTH A MALLAN ◽  
MURUKAN P. A ◽  
RITA ZARINA
Keyword(s):  
Comparative Study ◽  
Base Metal ◽  
Metal Alloys
Sign in / Sign up

Export Citation Format

Share Document