INVESTIGADORES
BJERG Ernesto Alfredo
artículos
Título:
Geometric analysis and timing of structures on mafic-ultramafic bodies and high grade metamorphic rocks, Sierras Grandes of San Luis, Argentina.
Autor/es:
DELPINO, S; DIMIERI, L; BJERG, E A; KOSTADINOFF, J; MOGESSIE, A; HOINKES, G; HAUZENBERGER, CH; FELFERNIG, A; BJERG, E A
Revista:
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
Editorial:
Elsevier
Referencias:
Lugar: Amsterdam; Año: 2001 vol. 14 p. 101 - 112
ISSN:
0895-9811
Resumen:
The study area comprises a portion of the
Sierras Grandes of San Luis Province in west-central Argentina. This
sector is composed of high-grade granulite facies metamorphic rocks,
mainly gneisses and migmatites, with intercalated igneous
maficultramafic bodies. These bodies occur as discontinuous lenses
along a narrow central belt concordant with the general NESW
structural trend. The granulite facies metamorphism reached by this
central area has been ascribed to the intrusion of the maficultramafic
bodies into an amphibolite facies metamorphic sequence. On both sides
of the maficultramafic bodies, a decrease of metamorphic grade to
amphibolite facies is apparent. Numerous pegmatitic bodies intruding
the metamorphic complex can be found elsewhere and, towards the western
limit of the study area, La Escalerilla metagranite constitutes one of
the larger granitic exposures of the Sierras. The results of the
structural analysis, done along cross-sections transverse to the
maficultramafic belt, allow us to establish a structural evolution for
this large geological feature. The described deformational events can
be correlated with the tectonic framework postulated for the southern
Pampean Ranges.