RT Journal Article
T1 The San Blas Pluton: An example of Carboniferousplutonism in the Sierras Pampeanas, Argentina
A1 Dahlquist, Juan A.
A1 Pankhurst, R.J.
A1 Rapela, Carlos W.
A1 Casquet Martín, César
A1 Fanning, C.M.
A1 Alasino, Pablo H.
A1 Baez, Miguel
AB New geochronological and geochemical data are reported for the San Blas Pluton (SBP), in the northwestern Sierra de Velasco, SierrasPampeanas, which intrudes Ordovician granitoids developed during the Famatinian orogeny. A precise Carboniferous age of 340±3 Ma isestablished by U–Pb dating of zircon using a sensitive high-resolution ion microprobe (SHRIMP). The SBP illustrates several petrological andgeochemical characteristics of previously reported Carboniferous granitoids in the Sierras Pampeanas. Their generation is consistent with aregional reheating of the crust at approximately 342 Ma, which resulted in the formation of relatively large amounts of granitic melts that wereemplaced in higher crustal levels along master fractures (older master shear zones of Lower Paleozoic age). The SBP can be chemically defined asa typical A-type granitoid related to postcollisonal or postorogenic magmatism. Its high REE content and extraordinarily high U and Thconcentrations may have economic significance. Many previously published Devonian and Carboniferous K–Ar dates are reset Ordovician ages,but the existence of other Carboniferous bodies in the Sierra de Velasco cannot be discounted until detailed mapping of the whole Sierra iscompleted.
PB Elsevier Science B.V., Amsterdam.
SN 0895-9811
YR 2006
FD 2006
LK https://hdl.handle.net/20.500.14352/49442
UL https://hdl.handle.net/20.500.14352/49442
LA eng
DS Docta Complutense
RD 9 abr 2025