Published 2002 | Version v1
Miscellaneous Open

Punta del Este terrane : a better knowledge

  • 1. Universidad de la Republica, Facultad de Ciencias, Montevideo (Uruguay)
  • 2. Instituto de Geociencias, Universidade de Sao Paulo, San Pablo (Brazil)

Description

Field Punta del Este (TPE) is constituted by a series of gneisses and migmatites formed in the range of 1000 and 900 Ma, and have been intensely reworked during Rio Doce orogeny (ca. 600-500 Ma). This cortical segment represents high-grade metamorphic terrain, correlatable with complex gneiss Southwest Africa, particularly with Kibariáno Belt - Namaqualanos recognized in the southwestern portion of Africa (Namibia). U-Pb zircon ages in tonalite granitoids indicate valuesbetween 1000 and 900 Ma and were interpreted as indicating the time of generation of these rocks. This should also be the age of high-grade metamorphism that affected a large part of the gneissic rocks of the region. Moreover, the anatectic related mobilized leucosomes ages of migmatites gave ca. 520-540 Ma, indicating that the metamorphic conditions (overlapping) during the Rio Doce orogeny reached at least the amphibolite facies. The metasedimentary cover TPE occurs in the vicinity of the towns of La Paloma Rocha. These are represented by a siliciclastic metasedimentary sequence represented by Rocha Formation. Despite the poly phase deformation and low grade metamorphism affecting this training, primary structures are common such as stratification plano-parallel, cross-bedding, hummock y and massive levels with gradational stratification

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Additional details

Additional titles

Original title (Spanish)
El terreno Punta del este: una aproximacion al conocimiento

Publishing Information

Imprint Place
Montevideo (Uruguay)
Imprint Pagination
28 p.
Report number
INIS-UY-GEO--682

INIS

Country of Publication
Uruguay
Country of Input or Organization
Uruguay
INIS RN
47087254
Subject category
S58: GEOSCIENCES;
Descriptors DEI
AMPHIBOLITES; DEFORMATION; GNEISSES; METAMORPHISM; NAMIBIA; STRATIFICATION; URUGUAY; ZIRCON
Descriptors DEC
AFRICA; DEVELOPING COUNTRIES; LATIN AMERICA; METAMORPHIC ROCKS; MINERALS; ROCKS; SILICATE MINERALS; SOUTH AMERICA

Optional Information

Notes
Extended abstracts of the II Colloquio Internacional Vendiano-Cambrico del Gondwana Occidental, del 7 al 8 Marzo de 2002, Montevideo Uruguay.