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Selected Works of Susan DeBari
Contribution to Book
Geology of the Sierra de Fiambala, northwestern Argentina: implications for Early Palaeozoic Andean tectonics
The Proto-Andean Margin of Gondwana (1998)
  • Grady C. Grissom
  • Susan M. Debari
  • Lawrence W. Snee
Abstract
This paper is included in the Special Publication entitled 'The proto- Andean margin of Gondwana', edited by R.J. Pankhurst and C.W. Rapela. Field mapping in conjunction with structural, metamorphic, and geochronological data document the tectono-thermal history of exhumed deep crustal rocks in the Sierra de Fiambala, NW Argentina. The range consists of two structural blocks distinguished by different metasedimentary sequences and different grades of metamorphism. Orthogneiss and paragneiss in the northern structural block may have a Precambrian history. Greenschist- to amphibolite-facies metamorphism, intrusion, and injection magmatization affected all rocks at 540-550 Ma. A subsequent event in the Late Cambrian to Ordovician (c.515 to 470 Ma) involved amphibolite- to granulite-facies metamorphism, mafic intrusion, and deformation, followed by cooling through mid-Palaeozoic time. The emplacement of Carboniferous (325-350 Ma) post-tectonic granites caused reheating and retrogression that was strongest toward the northeast part of the range. The Cambrian, Ordovician, and Carboniferous events in the Sierra de Fiambala were of regional extent as indicated by temporal correlations with events reported for other deep crustal rocks of the northern Sierras Pampeanas. Correlations between periods of intrusion and high-grade metamorphism in the northern Sierras Pampeanas and volcanic-sedimentary events in the adjacent supracrustal exposures confirm that rocks in the northern Sierras Pampeanas formed at deep (10-25 km) structural levels in the early Palaeozoic continental margin of Gondwana.
Keywords
  • Sierra de Fiambala,
  • Northwestern Argentina,
  • Andean tectonics
Disciplines
Publication Date
January 1, 1998
Editor
R. J. Pankhurst and Carlos W. Rapela
Publisher
Geological Society of London
Series
Geological Society Special Publications
DOI
10.1144/GSL.SP.1998.142.01.15
Citation Information
Grady C. Grissom, Susan M. Debari and Lawrence W. Snee. "Geology of the Sierra de Fiambala, northwestern Argentina: implications for Early Palaeozoic Andean tectonics" The Proto-Andean Margin of Gondwana Vol. 142 (1998) p. 297 - 323
Available at: http://works.bepress.com/susan-debari/34/