RT Book, Section
T1 Geoquímica isotópica (Sr y Nd) de las anortositas (“massif type anorthosites”)grenvillianas de las Sierras Pampeanas Occidentales (Argentina).Fuentes magmáticas e implicaciones geotectónicas
A1 Casquet Martín, César
A1 Galindo Francisco, María Del Carmen
A1 Rapela, Carlos W.
A1 Pankhurst, R.J.
A1 Baldo, Edgardo G.
A1 Dahlquist, Juan A.
A1 Fanning, C.M.
A1 González Casado, José Manuel
A1 Saavedra, Julio
A2 Lamolda, Marcos A.
AB Massif-type anorthosites are igneous complexes that consist for the most part of anorthosite, a plagioclase-rich plutonic rock. They are particularly abundant within or near the worldwide Grenvillian mobilebelt (1.0-1.2Ga), which resulted from the assembly of the Mesoproterozoic supercontinent of Rodinia.In two of the most western Sierras Pampeanas (Sierras of Maz and Espinal, NW of Argentina), twoanorthositic igneous complexes have been discovered recently (Casquet et al. 2005a). Coarse-grainedanorthosites is the predominant rock type in these complexes. The age of crystallization is of 1070 ± 41Ma (U-Pb SHRIMP, in zircons). These rocks have a superposed regional metamorphism of Ordovician age(431±30 Ma; U-Pb SHRIMP, in zircons). These complexes are the only ones mentioned in Argentina andare the first of recognized Grenvillian age in Sudamerica.Nd and Sr isotope composition suggest that primary magmas derived from a depleted source. Moreovermoderate contamination with an enriched continental component is also inferred. Nd model agessuggest that the depleted source formed coeval with the anorthosite magmatism, which is compatible witha mantle plume probably related to the early break up of Rodinia.
PB Instituto Geológico y Minero de España
SN 84-7840-592-5
YR 2005
FD 2005
LK https://hdl.handle.net/20.500.14352/53066
UL https://hdl.handle.net/20.500.14352/53066
LA spa
DS Docta Complutense
RD 8 abr 2025