INVESTIGADORES
VUJOVICH Graciela Irene
artículos
Título:
Detrital zircon analysis from the Neoproterozoic-Cambrian sedimentary cover (Cuyania terrane), Sierra de Pie de Palo, Argentina: Evidence of a rift and passive margin system?
Autor/es:
NAIPAUER, M., VUJOVICH, G.I., CINGOLANI, C.A., MCCLELLAND, W.C.
Revista:
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Año: 2010 p. 306 - 326
ISSN:
0895-9811
Resumen:
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Metamorphic basement and its Neoproterozoic to
Lower Cambrian cover exposed in the
Sierra de Pie de Palo, a basement block of the
Sierras Pampeanas in Argentina,
lie within the Cuyania terrane. Detrital zircon analysis of the cover sequence
which includes, in ascending order, the El Quemado, La Paz,
El Desecho, and Angacos Formations of the Caucete Group indicate a Laurentian origin
for the Cuyania terrane. The lower section represented by the El Quemado and La Paz Formations is interpreted
as having an igneous source related to a rift setting similar to that envisioned
for the southern and eastern margins of Laurentia at approximately 550 Ma. The
younger strata of the El Desecho Formation are correlative with the Cerro
Totora Formation of the Precordillera, and both are products of rift
sedimentation. Finally, the Angacos Formation and the correlative La Laja Formation of
the Precordillera were deposited on the passive margin developed on the Cuyania
terrane. The maximum Depositional ages
for the Caucete Group include ca. 550 Ma for the El Quemado Formation and ca.
531 Ma for the El Desecho Formation. Four different sediment sources areas were
interpreted in the provenance analysis. The main source is crystalline basement
dominated by early Mesoproterozoic igneous rocks related
to the Granite-Rhyolite province of central and eastern Laurentia. Possible
source areas for 1600 Ma metamorphic detrital zircons of the Caucete Group include
the Yavapai-Mazatzal province (ca. 1800-1600 Ma) of south-central to
southwestern Laurentia. Younger Mesoproterozoic zircon is likely derived from
Grenville-age medium- to high-grade metamorphic rocks and subordinate igneous
rocks that form the basement of Cuyania as well as the southern Grenville province of Laurentia itself. Finally,
Neoproterozoic igneous zircon in the Caucete Group records different magmatic
pulses along the southern Laurentian margin during opening of Iapetus and
break-up of Rodinia. Northwestern Cuyania terrane includes a small basement
component derived from the Granite-Rhyolite province of Laurentia,
which was the source for detrital zircons found in the middle Cambrian passive
margin sediments of Cuyania.