Mineralogy and Distribution of Critical Elements in the Sn-W-Pb-Ag-Zn Huanuni Deposit, Bolivia
Por:
Cacho, Andreu, Melgarejo, Joan-Caries, Camprubi, Antoni, Torro, Lisard, Castillo-Oliver, Montgarri, Torres, Belen, Artiaga, David, Tauler, Esperanca, Martinez, Alvaro, Campeny, Marc, Alfonso, Pura, Arce-Burgoa, Osvaldo R.
Publicada:
1 dic 2019
Resumen:
The polymetallic Huanuni deposit, a world-class tin deposit, is part of
the Bolivian tin belt. As a likely case for a ``mesothermal'' or
transitional deposit between epithermal and porphyry Sn types (or
shallow porphyry Sn), it represents a case that contributes
significantly to the systematic study of the distribution of critical
elements within the ``family'' of Bolivian tin deposits. In addition
to Sn, Zn and Ag, further economic interest in the area resides in its
potential in critical elements such as In, Ga and Ge. This paper
provides the first systematic characterisation of the complex mineralogy
and mineral chemistry of the Huanuni deposit with the twofold aim of
identifying the mineral carriers of critical elements and endeavouring
plausible metallogenic processes for the formation of this deposit, by
means of a multi-methodological approach. With In concentrations
consistently over 2000 ppm, the highest potential for relevant
concentrations in this metal resides in widespread tin minerals
(cassiterite and stannite) and sphalerite. Hypogene alteration
assemblages are hardly developed due to the metasedimentary nature of
host rocks, but the occurrence of potassium feldspar, schorl,
pyrophyllite and dickite as vein material stand for potassic to phyllic
or advanced argillic alteration assemblages and relatively
high-temperature (and low pH) mineralising fluids. District-scale
mineralogical zonation suggests a thermal zonation with decreasing
temperatures from the central to the peripheral areas. A district-scale
zonation has been also determined for delta S-34(VCDT) values, which
range -7.2 parts per thousand to 0.2 parts per thousand (mostly -7 parts
per thousand to -5 parts per thousand) in the central area and -4.2
parts per thousand to 1.0 parts per thousand (mainly constrained between
-2 parts per thousand and 1 parts per thousand) in peripheral areas.
Such values stand for magmatic and metasedimentary sources for sulfur,
and their spatial zoning may be related to differential reactivity
between mineralising fluids and host rocks, outwardly decreasing from
the central to the peripheral areas.
Filiaciones:
Cacho, Andreu:
Univ Barcelona, Dept Mineral Petrol & Prospeccio Geol, Fac Ciencies Terra, Carrer Marti & Franques S-N, E-08028 Barcelona, Spain
Melgarejo, Joan-Caries:
Univ Barcelona, Dept Mineral Petrol & Prospeccio Geol, Fac Ciencies Terra, Carrer Marti & Franques S-N, E-08028 Barcelona, Spain
Camprubi, Antoni:
Univ Nacl Autonoma Mexico, Inst Geol, Ciudad Univ, Coyoacan 04510, Cdmx, Mexico
Torro, Lisard:
Pontifical Catholic Univ Peru PUCP, Fac Sci & Engn, Geol Engn Program, Av Univ 1801, Lima 15088, Peru
Castillo-Oliver, Montgarri:
Macquarie Univ, ARC Ctr Excellence Core Crust Fluid Syst CCFS, N Ryde, NSW 2109, Australia
Macquarie Univ, GEMOC, Dept Earth & Planetary Sci, N Ryde, NSW 2109, Australia
Torres, Belen:
Univ Barcelona, Dept Mineral Petrol & Prospeccio Geol, Fac Ciencies Terra, Carrer Marti & Franques S-N, E-08028 Barcelona, Spain
Artiaga, David:
Univ Barcelona, Ctr Cient & Tecnol, Carrer Marti & Franques S-N, E-08028 Barcelona, Spain
Tauler, Esperanca:
Univ Barcelona, Dept Mineral Petrol & Prospeccio Geol, Fac Ciencies Terra, Carrer Marti & Franques S-N, E-08028 Barcelona, Spain
Martinez, Alvaro:
Univ Geneva, Dept Sci Terre, Rue Maraichers 13, CH-1205 Geneva, Switzerland
Campeny, Marc:
Univ Barcelona, Dept Mineral Petrol & Prospeccio Geol, Fac Ciencies Terra, Carrer Marti & Franques S-N, E-08028 Barcelona, Spain
Museu Ciencies Nat Barcelona, Dept Mineral, Passeig Picasso S-N, Barcelona 08003, Spain
Alfonso, Pura:
Univ Politecn Cataluna, Dept Enginyeria Minera Ind & TIC, Escola Tecn Super Enginyeria Mines Manresa, Avinguda Bases Manresa 61-73, Manresa 08242, Spain
Arce-Burgoa, Osvaldo R.:
Colegio Geologos Bolivia, Edificio Senor Exaltac Nro 4683, La Paz 8941, Bolivia
Eloro Resources Ltd, Av La Floresta 497,Of 101, Lima 15037, Peru
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