DOI: 10.1016/j.tecto.2020.228439
论文题名: Low-temperature thermochronology of the South Atlantic margin along Uruguay and its relation to tectonic events in West Gondwana
作者: Silveira Luiz Machado J.P. ; Ritter Jelinek A. ; Stephenson R. ; Gaucher C. ; Müller Bicca M. ; Chiglino L. ; Genezini F.A.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2020
卷: 784 语种: 英语
中文关键词: (U[sbnd]Th)/He
; Fission-tracks
; South Atlantic
; Thermochronology
; Uruguay
; West Gondwana
英文关键词: Apatite
; Buildings
; Fission reactions
; Silicate minerals
; Single crystals
; Structural geology
; Temperature
; Zircon
; Apatite fission track ages
; Basement structures
; Continental margin
; Large igneous provinces
; Lithosphere thinning
; Surface temperatures
; Thermal influence
; Thermotectonic evolution
; Geodynamics
; continental margin
; cooling
; exhumation
; geodynamics
; Gondwana
; low temperature
; magmatism
; mantle plume
; rifting
; tectonic structure
; thermochronology
; uplift
; volcanism
; Atlantic Ocean
; Atlantic Ocean (South)
; Uruguay
英文摘要: The geodynamic forces acting during Jurassic-Cretaceous South Atlantic rifting provoked intense transformations in West Gondwana, such as the reactivation of ancient basement structures, voluminous magmatism and general uplift of the new continental margins. Low-temperature thermochronology records cooling associated with uplift syn- and post-breakup along the Brazilian margin, while further south, in Uruguay, mostly pre-breakup uplift is identified. Thermochronometry data are scarce in Uruguay, but previous studies suggest that basement cooling and exhumation preceded West Gondwana breakup by hundreds of millions of years. To improve our knowledge of Uruguay's thermotectonic evolution, in this study we present 19 apatite fission-track ages, 42 apatite and 40 zircon (U[sbnd]Th)/He single crystal ages for the Uruguayan shield (UYS), from which we modeled 19 inverse thermal histories. Our results suggest that the UYS temperatures were below 200 °C since the early Paleozoic, and that cooling below 110 °C started during the Carboniferous, with continuous exhumation of the basement until Early Cretaceous. The onset of this long-term uplift is correlated with orogenesis and terrane accretions in the SW margin of West Gondwana during the Paleozoic. Lithosphere thinning and uplift preceding breakup contributed to the continuous Late Paleozoic to middle Mesozoic exhumation, until the voluminous volcanism of the Paraná-Etendeka Large Igneous Province (c. 133 Ma). This magmatic event, combined with the thermal influence of the Tristão da Cunha mantle plume and rift spreading, likely raised the basement geotherm during the Late Cretaceous. Models suggest a slight increase in temperatures of the UYS from Late Cretaceous until the Oligocene, when a final cooling to surface temperatures took place. Our findings corroborate a long and complex thermal history for Uruguay, with crustal uplift occurring essentially before West Gondwana breakup. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170714
Appears in Collections: 气候变化与战略
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作者单位: School of Geosciences, University of Aberdeen, United Kingdom; Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Instituto de Pesquisas Energéticas e Nucleares, Centro do Reator de Pesquisas, São Paulo, Brazil
Recommended Citation:
Silveira Luiz Machado J.P.,Ritter Jelinek A.,Stephenson R.,et al. Low-temperature thermochronology of the South Atlantic margin along Uruguay and its relation to tectonic events in West Gondwana[J]. Tectonophysics,2020-01-01,784