Protracted Magmatic-Hydrothermal History of the Río Blanco-Los Bronces District, Central Chile&lt;subtitle&gt;Development of World's Greatest Known Concentration of Copper&lt;/subtitle&gt;

Toro, Juan Carlos; Ortúzar, Javier; Zamorano, Jorge; Cuadra, Patricio; Hermosilla, Juan; Spröhnle, C.

doi:10.5382/sp.16.05

Cited by 10 publications

(10 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The syn-tectonic hydrothermal minerals used as kinematic indicators (fault steps in epidote, tourmaline, quartz, calcite, chlorite, biotite and muscovite; Piquer et al, 2016;Fig. 2C) form part of different hydrothermal systems with a total age range of 14 to 4 Ma (Maksaev et al, 2004;Toro et al, 2012;Deckart et al, 2013;Piquer et al, 2016), thus constraining the age of fault reactivation.…”

Section: Structural Geology Of the High Andes Of Central Chilementioning

confidence: 99%

Long-lived crustal damage zones associated with fault intersections in the high Andes of Central Chile

Romo

Yáñez

Rivera

et al. 2019

andgeo

View full text Add to dashboard Cite

Long-lived, high-angle fault systems constitute high-permeability zones that can localize the upward flow of hydrothermal fluids and magma throughout the upper crust. Intersections of these types of structures can develop complex interference patterns, which constitute volumes of damaged rock (networks of small-scale faults and fractures) where permeability may be significantly enhanced. This is relevant for understanding regional-scale structural controls on the emplacement of hydrothermal mineral deposits and volcanic centers, and also on the distribution of areas of active upper-crustal seismicity. In the high Andes of central Chile, regional-scale geophysical (magnetic, gravimetric, seismic) and structural datasets demonstrate that the architecture of this Andean segment is defined by NW- and NE-striking fault systems, oblique to the N-S trend of the magmatic arc. Fault systems with the same orientations are well developed in the basement of the Andes. The intersections of conjugate arc-oblique faults constitute the site of emplacement of Neogene intrusive complexes and giant porphyry Cu-Mo deposits, and define the location of major clusters of upper-crustal earthquakes and active volcanic centers, suggesting that these fault systems are still being reactivated under the current stress regime. A proper identification of one-dimensional, lithospheric-scale high-permeability zones located at the intersections of high-angle, arc-transverse fault systems could be the key to understanding problems such as the structural controls on magmatic and hydrothermal activity and the patterns of upper-crustal seismicity in the high Andes and similar orogenic belts

show abstract

Section: Structural Geology Of the High Andes Of Central Chilementioning

confidence: 99%

Long-lived crustal damage zones associated with fault intersections in the high Andes of Central Chile

Romo

Yáñez

Rivera

et al. 2019

andgeo

View full text Add to dashboard Cite

show abstract

“…The SFB is cut by porphyries of quartz monzonitic (PQM) and feldspathic (PFELD) compositions, with reported U-Pb zircon ages of 6.32 ± 0.09 Ma and 5.84 ± 0.03 Ma, respectively [31] ( Figure 1B). Several hydrothermal breccia types are recognized in Río Blanco: igneous, igneous/hydrothermal, hydrothermal (biotite and tourmaline bearing), and rock-flour breccias [34]. The hydrothermal breccias are closely related to the porphyry units and the bulk of the copper sulfide mineralization occurs as cement in these breccias.…”

Section: Geology Of the Río Blanco Depositmentioning

confidence: 99%

“…The youngest unit in the district corresponds to the La Copa Volcanic Complex (CVLC), which is located in the northern part of the deposit. The CVLC comprises crystalline tuffs (CHDAC, Dacitic chimney; U-Pb zircon age of 4.57 ± 0.08 Ma) and lithic tuffs (CHRIOL, Rhyolitic chimney; U-Pb zircon age of 4.31 ± 0.05 Ma) [34]. Magmatic and hydrothermal fluid flow was channeled and focused by both sets of preexisting oblique structures (NE and NW-striking faults) and, in turn, fault rupture was driven by high fluid pressures [35].…”

Section: Geology Of the Río Blanco Depositmentioning

confidence: 99%

Critical Metal Particles in Copper Sulfides from the Supergiant Río Blanco Porphyry Cu–Mo Deposit, Chile

et al. 2018

View full text Add to dashboard Cite

Porphyry copper–molybdenum deposits (PCDs) are the world’s most important source of copper, molybdenum and rhenium. Previous studies have reported that some PCDs can have sub-economic to economic grades of critical metals, i.e., those elements that are both essential for modern societies and subject to the risk of supply restriction (e.g., platinum group elements (PGE), rare earth elements (REE), In, Co, Te, Ge, Ga, among others). Even though some studies have reported measured concentrations of Pd and Pt in PCDs, their occurrence and mineralogical forms remain poorly constrained. Furthermore, these reconnaissance studies have focused predominantly on porphyry Cu–Au deposits, but very limited information is available for porphyry Cu–Mo systems. In this contribution, we report the occurrence of critical metal (Pd, Pt, Au, Ag, and Te) inclusions in copper sulfides from one of the largest PCDs in the world, the supergiant Río Blanco-Los Bronces deposit in central Chile. Field emission scanning electron microscope (FESEM) observations of chalcopyrite and bornite from the potassic alteration zone reveal the presence of micro- to nano-sized particles (<1–10 μm) containing noble metals, most notably Pd, Au, and Ag. The mineralogical data show that these inclusions are mostly tellurides, such as merenskyite ((Pd, Pt) (Bi, Te)2), Pd-rich hessite (Ag2Te), sylvanite ((Ag,Au)Te2) and petzite (Ag3AuTe2). The data point to Pd (and probably Pt) partitioning in copper sulfides during the high-temperature potassic alteration stage, opening new avenues of research aimed at investigating not only the mobility of PGE during mineralization and partitioning into sulfides, but also at exploring the occurrence of critical metals in porphyry Cu–Mo deposits.

show abstract

“…1B). Several hydrothermal breccia types are recognized in Río Blanco: igneous, igneous/hydrothermal, hydrothermal (biotite and tourmaline bearing), and rock-flour breccias [33]. The hydrothermal breccias are closely related to the porphyry units and the bulk of the copper sulfide mineralization occurs as cement in these breccias.…”

Section: Geology Of the Río Blanco Depositmentioning

confidence: 99%

“…The youngest unit in the district corresponds to the La Copa Volcanic Complex (CVLC), which is located in the northern part of the deposit. The CVLC comprises crystalline tuffs (CHDAC, Dacitic chimney; U-Pb zircon age of 4.57 ± 0.08 Ma) and lithic tuffs (CHRIOL, Rhyolitic chimney; U-Pb zircon age of 4.31 ± 0.05 Ma) [33]). Magmatic and hydrothermal fluid flow was channeled and focused by both sets of preexisting oblique structures (NE and NW -striking faults) and, in turn, fault rupture was driven by high fluid pressures [34].…”

Section: Geology Of the Río Blanco Depositmentioning

confidence: 99%

Critical metal particles in copper sulfides from the supergiant Río Blanco porphyry Cu-Mo deposit, Chile

Crespo¹,

Reich²,

Barra³

et al. 2018

Preprint

View full text Add to dashboard Cite

Porphyry copper-molybdenum deposits (PCDs) are the world’s most important source of copper, molybdenum and rhenium. Previous studies have reported that some PCDs can have sub-economic to economic grades of critical metals, i.e., those elements that are both essential for modern societies and subject to the risk of supply restriction (e.g., platinum group elements (PGE), rare earth elements (REE), In, Co, Te, Ge, Ga, among others). Even though some studies have reported measured concentrations of Pd and Pt in PCDs, their occurrence and mineralogical form remain poorly constrained. Furthermore, these reconnaissance studies have focused predominantly on porphyry Cu-Au deposits, but very limited information is available for porphyry Cu-Mo systems. In this contribution, we report the occurrence of critical metal (Pd, Pt, Au, Ag, and Te) inclusions in copper sulfides from the world’s largest PCD, the supergiant Río Blanco-Los Bronces deposit in central Chile. Field emission scanning electron microscope (FESEM) observations of chalcopyrite and bornite from the potassic alteration zone reveal the presence of micro- to nano-sized particles (<1-10 μm) of noble metals, most notably Pd, Au, and Ag. The high-resolution data show that these inclusions are mostly tellurides, such as merenskyite [PdTe2], Pd-rich hessite [Ag2Te], sylvanite [(Ag, Au)Te2] and petzite [Ag3AuTe2]. The data point to Pd (and probably Pt) partitioning in copper sulfides during the high-temperature potassic alteration stage, opening new avenues of research aimed at investigating not only the mobility of PGE during mineralization and partitioning into sulfides, but also at evaluating the potential of porphyry Cu-Mo deposits as a source for noble metals.

show abstract

Protracted Magmatic-Hydrothermal History of the Río Blanco-Los Bronces District, Central Chile<subtitle>Development of World's Greatest Known Concentration of Copper</subtitle>

Cited by 10 publications

References 19 publications

Long-lived crustal damage zones associated with fault intersections in the high Andes of Central Chile

Long-lived crustal damage zones associated with fault intersections in the high Andes of Central Chile

Critical Metal Particles in Copper Sulfides from the Supergiant Río Blanco Porphyry Cu–Mo Deposit, Chile

Critical metal particles in copper sulfides from the supergiant Río Blanco porphyry Cu-Mo deposit, Chile

Contact Info

Product

Resources

About