DOI: 10.1016/j.tecto.2021.228884
论文题名: Lithosphere of South American intracratonic basins: Electromagnetic and potential field data reveal cratons, terranes, and sutures
作者: Dragone G.N. ; Bologna M.S. ; Ussami N. ; Giménez M.E. ; Alvarez O. ; Lince Klinger F.G. ; Correa-Otto S.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2021
卷: 811 语种: 英语
中文关键词: Cratons
; Density
; Magnetotellurics
; Paraná
; Rio Tebicuary
; Sutures
英文关键词: Geophysics
; Physics
; Broadband station
; Crustal conductors
; Density anomalies
; Magnetotelluric surveys
; Mantle xenoliths
; Metasomatic process
; Potential field datum
; Sub-continental lithospheric mantles
; Structural geology
; electrical resistivity
; electromagnetic field
; igneous province
; intracratonic basin
; magnetotelluric method
; potential field
; subsidence
; suture zone
; upper mantle
; Brazil
; Parana [Brazil]
英文摘要: A magnetotelluric survey comprising 18 broadband stations disposed along a 450 km-long profile was carried out at the transition between the Chaco-Paraná (CPB) and the Paraná (PB) intracratonic basins in northeastern Argentina. Three-dimensional inversions of the responses show that the CPB and southern PB lithospheres are resistive (~103 Ω m) down to 120 km, but with distinct crustal and upper mantle electrical properties. Also, Bouguer gravity and density anomalies are positive at CPB, whereas they are negative at PB. We associate the CPB lithosphere with the Paleoproterozoic Rio Tebicuary craton and the southern PB lithosphere with an ancient and buried piece of craton, the Southern Paraná craton. Geochemical data of mantle xenoliths from the Cenozoic alkaline/carbonatitic province within the Rio Tebicuary craton suggest a subcontinental lithospheric mantle affected by metasomatic processes, which explains its lower resistivity (reaching values as low as 300 Ω m) and higher density (#Mg = 0.87). In contrast, the Southern Paraná craton is more resistive (>103 Ω m) and less dense, suggesting a de-hydrated, depleted, and thicker craton. These cratons are separated by a crustal conductor (15 to 20 km depth; 1–10 Ω m) that we interpret as a southward continuation of a linear anomaly (Paraná Axial Anomaly) defined in former induction studies within the PB in Brazil. Hence, we redefined the trace of this conductive lineament: instead of bending towards the Torres Syncline, it continues inside the CPB. We propose the lineament to be an Early Neoproterozoic suture zone that controlled the location of maximum subsidence in the intracratonic basins during the Paleozoic. In the Early Cretaceous, the Paraná Axial Anomaly was the site of maximum extrusion and deposition of Serra Geral basalts. This anomaly separates compositionally distinct cratonic lithospheres along its path. Melting of this heterogeneous and enriched mantle created the Paraná igneous province. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170798
Appears in Collections: 气候变化与战略
There are no files associated with this item.
作者单位: Universidade de São Paulo, Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Departamento de Geofísica, São Paulo, Brazil; Instituto Geofísico Sismológico Volponi (IGSV), Universidad Nacional de San Juan, Facultad de Ciencias Exactas, Físicas y Naturales, San Juan, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
Recommended Citation:
Dragone G.N.,Bologna M.S.,Ussami N.,et al. Lithosphere of South American intracratonic basins: Electromagnetic and potential field data reveal cratons, terranes, and sutures[J]. Tectonophysics,2021-01-01,811