Tracing hotspot traces in the Andes

Andean geology, Journal Year: 2024, Volume and Issue: 51(1), P. 1 - 1

Published: Jan. 31, 2024

Two segments of subduction the Nazca plate beneath South American occur at low angles based on seismic hypocenter locations, approaching nearly horizontal below ~100 km in depth. In contrast with most rest zone, two segments, central Chile, and northern Peru, lack active volcanoes along crest Andes have more subdued topography to east Andean crest. Each low-angle segment occurs intersection inferred mantle hotspot traces Peru-Chile Trench: ridge (at southern part Peruvian segment), Juan Fernández island-seamount chain (offshore Chilean segment). A third trace, Galápagos-Carnegie ridge, may be correlated a zone incipient Colombia. The importance such contributing is strengthened by updated American-Nazca reconstructions, including three oceanic traces, comparison new isotopic date compilation igneous rocks from mountain range. reconstructed Pacific-hotspot models Nazca-Farallon plate, encountered offshore Peru ~65 Ma, broadening arc volcanism east; trace-trench migrated gradually then rapidly southward, widening Bolivia Argentina; it stabilized about 13 Ma producing contemporary Pampean segment. also been responsible for formation Manihiki Plateau Pacific much earlier, ~125 Ma. Easter-Nazca trace intersected Colombia before ~50 southward Ecuador beginning ~15 progressive implied migrating volcanic cessation Peru. only recently apparently inducing magmatism reconstructions magmatic history provided here strongly support previously proposed genetic relationship subduction. Additionally, suggest remnants older subducted asthenosphere sourced post-rift eastern Brazil Paraguay, which cannot explained otherwise simple mechanisms.

Language: Английский

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Fluid geochemistry of the Cerro Galán geothermal system (Southern Puna, Argentina): Implications for the geothermal potential of one of the youngest giant calderas in the Andes

Journal of Volcanology and Geothermal Research, Journal Year: 2024, Volume and Issue: 450, P. 108089 - 108089

Published: May 1, 2024

Language: Английский

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PORPHYRY COPPER RECURRENCE IN THE ANDES OF CHILE AND ARGENTINA

Economic Geology, Journal Year: 2024, Volume and Issue: 119(5), P. 995 - 1003

Published: Aug. 1, 2024

Abstract Porphyry Cu deposits in the Chilean and Argentinian central Andes occur a series of orogen-parallel magmatic arcs, which migrated episodically eastward since Early Cretaceous. The three Cenozoic belts, corresponding to Paleocene-early Eocene, middle Eocene-early Oligocene, Miocene-early Pliocene epochs, cut obliquely across composite belt subeconomic porphyry mineralization formed at several times during Late Carboniferous Triassic interval. Based mainly on U-Pb zircon Re-Os molybdenite ages, 10 centers, including major all occupy same sites as late Paleozoic-Triassic where their respective arcs cross one another. recurrent are believed be underlain by long-lived dike conduits that were utilized least twice—first then again Cenozoic—to rapidly transmit hydrous magma from deep shallow levels crust. Contenders for preferential localization include arc-oblique fault subjacent ductile shear zones—transcrustal discontinuities—long hypothesized present region, particularly they intersect associated belts. Regardless controls recurrence, alteration zones hosted volcanic plutonic rocks Chile Argentina must considered prime exploration targets potentially large, high-grade deposits.

Language: Английский

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A new remote-sensing-based volcanic debris avalanche database of Northwest Argentina (Central Andes)

Landslides, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 18, 2024

Language: Английский

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High-resolution seismic tomography of the transition zone from normal to flat slab subduction in central Chile: Implications for volcanoes, plate coupling and flat subduction

Earth and Planetary Science Letters, Journal Year: 2024, Volume and Issue: 651, P. 119167 - 119167

Published: Dec. 13, 2024

Language: Английский

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Seismicity and Present‐Day Crustal Deformation in the Southern Puna Plateau

Journal of Geophysical Research Solid Earth, Journal Year: 2024, Volume and Issue: 129(12)

Published: Dec. 1, 2024

Abstract The Southern Puna plateau in the central Andes has a complicated tectonic history that includes episodes of distributed shortening and extension, lithospheric delamination, uplift Quaternary backarc volcanism. In this study, upper crustal structure present‐day deformation area is investigated using new regional earthquake catalog derived with deep‐learning‐based phase picker. Results show abundant strike‐slip seismicity at shallow depths eastern reveals active fault systems indicates N‐S extension/E‐W compression changes orientation relative magnitude from north to south. A broad zone seismic quiescence western may indicate decoupling large‐scale deformation. region separating exhibits complex stress field can be related boundary east/west oriented middle‐to‐lower flow main volcanic arc. Southeast Sierras Pampeanas, deepens dominated by conjugate reverse faulting structures associated direction plate convergence. Vp Vs velocity models crust obtained through local tomography improved low‐velocity anomalies near intermontane basins, except Antofagasta basin where high‐velocity anomaly possibly represents intrusive component basaltic Below Cerro Galan caldera, an 10‐day long swarm observed which perturbations fluids top magmatic system feeds volcano.

Language: Английский

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Revisiting the Holocene tephrochronology of northwestern Argentina: Insights from geochemical characterization of the tephras from the Tafí valley

Journal of South American Earth Sciences, Journal Year: 2023, Volume and Issue: 134, P. 104745 - 104745

Published: Dec. 19, 2023

Language: Английский

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