Magmatic and metallogenetic episodes in the northern tin belt, cordillera real, Bolivia

McBride, Sandra L.; Robertson, Ronald C. R.; Clark, Alan H.; Farrar, Edward

doi:10.1007/bf01822089

Cited by 55 publications

(59 citation statements)

References 31 publications

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“…In the Cordillera Oriental of northwestern Bolivia, however, granitoid (and lamprophyric) intrusion and local dacitic volcanism in the Cordillera Real-Cordillera Quimsa Cruz seg ment of the Inner Arc may indeed have commenced earlier, at ~28.4 Ma (oldest conventional K-Ar date for the Cerro Illimani Complex) (McBride et al, 1983). Moreover, 40 Ar/ 39 Ar total-fusion and K-Ar ages ranging from 21 Ma to as old as 29 Ma (and for various mineral species) have been reported for vol canic sandstone units in the Salla Formation at the boundary between the Cordillera Quimsa Cruz and Altiplano (Sempere et al, 1994, and references therein).…”

Section: Comparison Of Cenozoic Magmatic Activity In the Main And Innmentioning

confidence: 98%

“…The approximate limits of the Zongo-San Gabán tectonothermal zone (ZSGZ) is outlined by the heavy stippling, and the area lacking Tertiary magmatism (Zone 2) is shown by the crosshatched pattern. The eastern edge of the foreland fold-and-thrust belt is from Corvalan et al (1981). dacitic, basaltic, and lamprophyric units, for which conventional K-Ar ages outline a decrease in age toward the south (McBride et al, 1983;Avila, 1990); and (4) a southern zone exposing a sequence of Upper Miocene (~5 Ma) to upper Oligocene (~25 Ma) ash-flow tuffs, lavas, and subvolcanic intrusions of prob able mixed mantle-crustal derivation, constitut ing the aerially extensive Morococala and Kari Kari-Los Frailes volcanic fields, as well as numerous more restricted centers (Francis et al, 1981;Schneider and Halls, 1985;Koeppen et al, 1987;Schneider, 1987;Ericksen et al, 1990;Luedke et al, 1990;Kennan et al, 1995). However, the petrographic and geochemical character of the Bolivian peraluminous suites, and in particular those of the Morococala, Los Frailes, and Kari Kari fields, are not fully docu mented.…”

Section: Salient Tertiary Tectono-magmatic Features Of the Orocline Rmentioning

confidence: 99%

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An Integrated Tectono-Magmatic Model for the Evolution of the Southern Peruvian Andes (13-20°S) since 55 Ma

Sandeman

Clark

Farrar

1995

International Geology Review

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The definition and characterization of the Oligocene-Miocene Crucero Supergroup of the southern Peru Inner Arc domain provide a previously unavailable lithostratigraphic framework for the clarification of the geodynamic context of magmatism across the southern Peruvian transect. We integrate new lithostratigraphic, petrologic, and 40 Ar/ 39 Ar geochronologic data for these volcanic and hypabyssal rocks with published information to establish a geotectonic model for the transect since 55 Ma.The early Eocene to Early Miocene tectono-magmatic history of the region was controlled by the evolution of a flat-subduction regime, which was initiated at ~52 Ma with the onset of rapid convergence, terminating the magmatic and hydrothermal activity of the Toquepala superunit of the Coastal Batholith. Collision of the flat slab with the leading edge of the Brazilian Shield lithospheric mantle at 39-40 Ma resulted in catastrophic failure of the overriding plate and crustal-scale, NE-directed ramping, generating the "Incaic" Zongo-San Gaban tectonothermal zone in the proto-Cordillera Oriental. Failure of the flat slab (~37 Ma), its progressive foundering into the asthenosphere (from ~37 to 20 Ma), and the upwelling of asthenosphere in its wake are inferred to have generated an eastward-migrating thermal anomaly that severely weakened the lower crust. This resulted in the resumption of Main Arc magmatism in the protoCordillera Occidental (~32 Ma) in an axial regime of transtension, followed at 29 Ma by quasiinstantaneous broadening of the arc to a width of ~200 km. Further continentward arc expansion into the Inner Arc at ~25 Ma, generating the mixed crust-and mantle-derived suites of the Picotani Group, resulted in a 360-km-wide swath of magmatism. Termination of magmatism in the Inner Arc at ~22 Ma reflected the waning stages of anomalous mantle flow associated with foundering of the slab, and was accompanied by substantial uplift and crustal thickening.The subsequent evolution of the transect was initiated and prompted by the broad zone of thermally weakened lower crust. Ductile shortening of the lower crust from ~22 to 17 Ma generated widespread crustal thickening and uplift across the orogen, and was accompanied by the antithetic oceanward subduction of Brazilian Shield lithosphere beneath the Inner Arc and the initiation of thrusting and folding along the Sub-Andean zone. Delamination and, probably, detachment of the Brazilian Shield from its lithospheric mantle root, as well as partial melting of this root, yielded enriched mafic melts that ascended into the orogenic crust and contributed both thermally and through the release of volatiles to the generation of the Quenamari Group.We emphasize the spatial association of the Crucero Supergroup and comparable suites of the Bolivian Cordillera Oriental with the Bolivian Orocline, and delimit a ~250-km amagmatic longitudinal zone separating the sites of anatexis in southern Peru and northern Bolivia. This is inferred to represent the zone of maximum orthogonal convergence thro...

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Section: Comparison Of Cenozoic Magmatic Activity In the Main And Innmentioning

confidence: 98%

Section: Salient Tertiary Tectono-magmatic Features Of the Orocline Rmentioning

confidence: 99%

An Integrated Tectono-Magmatic Model for the Evolution of the Southern Peruvian Andes (13-20°S) since 55 Ma

Sandeman

Clark

Farrar

1995

International Geology Review

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“…occurred in the same belt, although the two groups are juxtaposed, with little or no areal overlap, only in the northern part (e.g. McBride et al, 1983;Clark et al, 1990). Genesis of the enigmatic coexistence is discussed later.…”

Section: Felsic Magmatism In the Bolivian Tin Beltmentioning

confidence: 96%

Sedimentary Crust and Metallogeny of Granitoid Affinity: Implications from the Geotectonic Histories of the Circum‐Japan Sea Region, Central Andes and Southeastern Australia

Sato

2012

Resource Geology

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Metallogeny of granitoid affinity was reviewed from the aspect of geotectonic history of the continental crust, particularly of the genesis of sedimentary crust involved in magmatism. The redox state of granitoids and related mineralization shows a remarkable contrast between the east and west sides of the Pacific Rim, but if examined closely, the reduced-type and oxidized-type granitoid provinces are juxtaposed in three regions: the circum-Japan Sea region, the central Andes, and the Lachlan Fold Belt in southeastern Australia. Comparative study of these regions revealed that the reduced-type magmatism associated with Sn mineralization generated in thick sedimentary crust which formed in three geotectonic environments: (i) accretionary terrane along a subduction zone (e.g. Jurassic East Asia), (ii) continental rift (e.g. Early Paleozoic Andes), and (iii) mega-fan (e.g. Early Paleozoic southeastern Australia). A collisional orogen can provide large amounts of clastic sediment to these environments. The age gap between the magmatism and sedimentation varies depending on the tectonic evolution of individual regions. Thin sedimentary crust may not play an essential role for the reduced-type magmatism. The oxidized-type magmatism associated with porphyry Cu and other mineralization generated in the crust which was initially carbon-free igneous crust or modified from sedimentary crust by magmatism. Subduction-related basaltic magmas are relatively oxidized, and may enhance fO 2 conditions of granitoid activity. Repeated magmatism in a monotonous convergent margin may be favorable for porphyry Cu mineralization as exemplified in the eastern Pacific Rim.

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“…The sedimentation age of the rocks is well constrained by biostratigaphy (e.g., Kley et al, 1997;Egenhoff et al, 2004, for the Ordovician rocks to the south of Llallagua; and Gordon, 1944, for the Devonian quartzite in the vicinity of the Llallagua deposit). Related granite intrusions of probably Triassic (according to K-Ar studies; McBride et al, 1983) or Permian-Carboniferous age (according to Rb-Sr data; Miller and Harris, 1989) are exposed only in the northern sector of the Bolivian tin belt. The Andean orogeny is mainly characterised by large-scale thrusting and weak folding (e.g., Kley et al, 1997;Decelles and Horton, 2003) ranging in age from at least about 23 Ma up to Quaternary (Sempere et al, 1990;Gubbels et al, 1993) and accompanied by periods of high volcanic activity Pichavant et al, 1988;Ericksen et al, 1990).…”

Section: Regional Context and Implications For The Genesis Of Tin Minmentioning

confidence: 99%

U–Pb SHRIMP geochronology of Th-poor, hydrothermal monazite: An example from the Llallagua tin-porphyry deposit, Bolivia

Kempe

Lehmann

Wolf

et al. 2008

Geochimica et Cosmochimica Acta

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Magmatic and metallogenetic episodes in the northern tin belt, cordillera real, Bolivia

Cited by 55 publications

References 31 publications

An Integrated Tectono-Magmatic Model for the Evolution of the Southern Peruvian Andes (13-20°S) since 55 Ma

An Integrated Tectono-Magmatic Model for the Evolution of the Southern Peruvian Andes (13-20°S) since 55 Ma

Sedimentary Crust and Metallogeny of Granitoid Affinity: Implications from the Geotectonic Histories of the Circum‐Japan Sea Region, Central Andes and Southeastern Australia

U–Pb SHRIMP geochronology of Th-poor, hydrothermal monazite: An example from the Llallagua tin-porphyry deposit, Bolivia

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