DOI: 10.1007/s00531-013-0902-8
Scopus记录号: 2-s2.0-84902485578
论文题名: Variability over time in the sources of South Portuguese Zone turbidites: Evidence of denudation of different crustal blocks during the assembly of Pangaea
作者: Pereira M.F. ; Ribeiro C. ; Vilallonga F. ; Chichorro M. ; Drost K. ; Silva J.B. ; Albardeiro L. ; Hofmann M. ; Linnemann U.
刊名: International Journal of Earth Sciences
ISSN: 14373254
出版年: 2014
卷: 103, 期: 5 起始页码: 1453
结束页码: 1470
语种: 英语
英文关键词: Carboniferous basins
; Provenance analysis
; U-Pb zircon geochronology
; Variscan orogeny
; Whole-rock geochemistry
Scopus关键词: Carboniferous
; crustal structure
; denudation
; geochemistry
; geochronology
; Gondwana
; graywacke
; Hercynian orogeny
; mudstone
; Pangaea
; provenance
; sedimentation
; trace element
; turbidite
; zircon
; Iberian Peninsula
英文摘要: This study combines geochemical and geochronological data in order to decipher the provenance of Carboniferous turbidites from the South Portuguese Zone (SW Iberia). Major and trace elements of 25 samples of graywackes and mudstones from the Mértola (Visean), Mira (Serpukhovian), and Brejeira (Moscovian) Formations were analyzed, and 363 U-Pb ages were obtained on detrital zircons from five samples of graywackes from the Mira and Brejeira Formations using LA-ICPMS. The results indicate that turbiditic sedimentation during the Carboniferous was marked by variability in the sources, involving the denudation of different crustal blocks and a break in synorogenic volcanism. The Visean is characterized by the accumulation of immature turbidites (Mértola Formation and the base of the Mira Formation) inherited from a terrane with intermediate to mafic source rocks. These source rocks were probably formed in relation to Devonian magmatic arcs poorly influenced by sedimentary recycling, as indicated by the almost total absence of pre-Devonian zircons typical of the Gondwana and/or Laurussia basements. The presence of Carboniferous grains in Visean turbidites indicates that volcanism was active at this time. Later, Serpukhovian to Moscovian turbiditic sedimentation (Mira and Brejeira Formations) included sedimentary detritus derived from felsic mature source rocks situated far from active magmatism. The abundance of Precambrian and Paleozoic zircons reveals strong recycling of the Gondwana and/or Laurussia basements. A peri-Gondwanan provenance is indicated by zircon populations with Neoproterozoic (Cadomian-Avalonian and Pan-African zircon-forming events), Paleoproterozoic, and Archean ages. The presence of late Ordovician and Silurian detrital zircons in Brejeira turbidites, which have no correspondence in the Gondwana basement of SW Iberia, indicates Laurussia as their most probable source. © 2013 Springer-Verlag Berlin Heidelberg. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84902485578&doi=10.1007%2fs00531-013-0902-8&partnerID=40&md5=33cf38911e0bc4654d07104074123137
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/70400
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: IDL, Departamento de Geociencias, ECT, Universidade de Evora, Evora, Portugal; CGE, Departamento de Geociencias, ECT, Universidade de Evora, Evora, Portugal; CICEGe, FCT, Universidade Nova de Lisboa, Lisbon, Portugal; Eberhard Karls Universität Tübingen, Tübingen, Germany; IDL, Departamento de Geologia, FC Universidade de Lisboa, Lisbon, Portugal; Senckenberg Naturhistorische Sammlungen Dresden, Dresden, Germany
Recommended Citation:
Pereira M.F.,Ribeiro C.,Vilallonga F.,et al. Variability over time in the sources of South Portuguese Zone turbidites: Evidence of denudation of different crustal blocks during the assembly of Pangaea[J]. International Journal of Earth Sciences,2014-01-01,103(5)