El cenozoico del alto río Teno, Cordillera principal, Chile central: Estratigrafía, plutonismo y su relación con estructuras profundas

Translated title of the contribution: The cenozoic of the upper Teno river, Cordillera principal, central Chile: Stratigraphy, plutonism and their relation with deep structures

José Piquer, Juan Carlos Castelli, Reynaldo Charrier, Gonzalo Yáñez

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)

Abstract

The Cenozoic geologic evolution of the central part of the Cordillera Principal at ~35°S, is intimately related to the geodynamic evolution of deep crustal structures, which during different stages controlled the deposition of volcanosedimentary sequences, and the ascent and emplacement of epizonal intrusions. Newly defined stratigraphy around these structures confirms the Cenozoic age of a group of pyroclastic and sedimentary rocks, which conformably underlie andesitic lavas of the Abanico Formation (assigned to the Late Eocene-Early to Middle Miocene). Intrusive rocks correspond to four main phases (from oldest to youngest: diorite, granodiorite, rhyo-dacitic and dacitic porphyry), which occurs in a North-South trending belt. The granodiorite was dated at 7.8±0.4 Ma (K-Ar in biotite). Rhyo-dacitic porphyries, considered as a marginal lithodeme of the granodiorite, yielded 7.9±0.4 Ma (K-Ar in plagioclase phenocrysts). Two main structures of regional importance were observed: the El Fierro thrust, and, towards the west, the Infiernillo-Los Cipreses Fault System. In the characterization of the latter, magnetic modeling of cross-sections were analyzed as a complement to the geologic information. The ascent of the different intrusive phases mentioned before, is interpreted as being controlled by the Infiernillo-Los Cipreses Fault System. This structure, as well as the El Fierro thrust, acted as a basin-margin normal fault during the Late Eocene-Middle Miocene, controlling the deposition of the Abanico Formation. These faults were reactivated as reverse faults during an episode of major tectonic contraction and magmatic-induced high fluid pressure in the Late Miocene, focusing the ascent of the intrusive bodies.

Translated title of the contributionThe cenozoic of the upper Teno river, Cordillera principal, central Chile: Stratigraphy, plutonism and their relation with deep structures
Original languageSpanish
Pages (from-to)32-53
Number of pages22
JournalAndean Geology
Volume37
Issue number1
Publication statusPublished - 2010

ASJC Scopus subject areas

  • Geology
  • Geochemistry and Petrology
  • Stratigraphy
  • Palaeontology

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