DOI: 10.1016/j.tecto.2020.228373
论文题名: Aeromagnetic patterns in Southern Uruguay: Precambrian-Mesozoic dyke swarms and Mesozoic rifting structural and tectonic evolution
作者: Nuñez Demarco P. ; Masquelin H. ; Prezzi C. ; Aïfa T. ; Muzio R. ; Loureiro J. ; Peel E. ; Campal N. ; Sánchez Bettucci L.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2020
卷: 789 语种: 英语
中文关键词: Aeromagnetic data
; Dyke swarm
; Mesozoic Rift
; Shear zones
; Southern Uruguay
; Transfer zone
英文关键词: Magnetism
; Shear flow
; Airborne magnetic data
; Euler deconvolution
; Geophysical analysis
; Mesozoic rifting
; Proterozoic basement
; Structural feature
; Tectonic evolution
; Vertical derivatives
; Faulting
; aeromagnetic survey
; dike swarm
; geological mapping
; magnetic survey
; Mesozoic
; orogeny
; Precambrian
; rifting
; shear zone
; spatial distribution
; structural geology
; tectonic evolution
; Uruguay
英文摘要: New high-resolution airborne magnetic data of Uruguay allowed constructing new maps concerning the spatial distribution of dyke swarms, main faults and other magnetic bodies, which compose the Uruguayan Shield. We combined geophysical analyses (vertical derivatives, upward continuation, Euler deconvolution), structural analyses of the magnetic maps and previous geological data in order to discriminate the main structural features of the Uruguayan Shield and contribute to a better understanding of its tectonic evolution. The magnetic maps revealed several outstanding features in the Uruguayan Shield. The Paleoproterozoic dyke swarm is larger, denser, more widespread and complex than originally thought, suggesting a possible plume origin. In addition, a new Mesozoic dyke swarm, as complex as the previous one, was identified crosscutting the Paleoproterozoic dyke swarm and the Neoproterozoic orogenic structures. Moreover, this swarm is connected to volcanic calderas in the Merín basin, and shows displacements along Neoproterozoic shear zones, in the magnetic maps, revealing its brittle reactivation during Mesozoic times. The new observations clarify how Proterozoic basement structures controlled the development of the Mesozoic rift. Paleoproterozoic dyke swarms were reactivated as normal faults and Neoproterozoic structures hindered the rift growth, deflecting the deformation in transcurrent movements. Meanwhile, the Mesozoic dyke swarm was developed in a perpendicular direction to the Neoproterozoic structures. Moreover, these findings contradict the current rift model for Uruguay and rise a new model in which the Mesozoic rift developed as two rift basins connected by a central transfer zone, generated by the reactivation of Dom Feliciano Belt structures, between the Sierra Ballena and Sarandí del Yí Shear Zones. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170669
Appears in Collections: 气候变化与战略
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作者单位: Instituto de Ciencias Geológicas, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; IGeBa, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina; CNRS, Géosciences Rennes - Universite Rennes, Rennes, France; Dirección Nacional de Minería y Geología, Montevideo, Uruguay
Recommended Citation:
Nuñez Demarco P.,Masquelin H.,Prezzi C.,et al. Aeromagnetic patterns in Southern Uruguay: Precambrian-Mesozoic dyke swarms and Mesozoic rifting structural and tectonic evolution[J]. Tectonophysics,2020-01-01,789