Resumen de Ordovician peraluminous granites in the Sierra de Pie de Palo, Western Sierras Pampeanas of Argentina: Geotectonic Implications
Edgardo G. Baldo, Juan A. Dahlquist, César Casquet Martín, Carlos Washington Rapela, Robert John Pankhurst, C. Galindo, C. M. Fanning, Carlos Dino Ramacciotti
- español
Sills of garnet-biotite-muscovite peraluminous granite were injected into the upper part of the nappe stacking from the Sierra de Pie de Palo, formed during the Famatinian orogeny (Ordovician). Two studied granites yielded SHRIMP U-Pb zircon ages of 474 ± 6 Ma and 470 ± 10 Ma, indicating that they were largely coeval with thrusting. Structural similarities with Himalayan leucogranites injected into the upper part of the Greater Himalayan Sequence during India–Asia collision suggest a similar geotectonic scenario for the Famatinian granites. It is suggested that felsic magmas were generated at the root of the thrust plane, probably close to the Famatinian magmatic arc along the Western Gondwana margin.
- English
Granitos peraluminosos con granate, biotita y moscovita, se emplazaron como sills en la unidad superior de la secuencia de cabalgamientos imbricados que forma la sierra de Pie de Palo, durante la orogénesis Famatiniana (Ordovícico inferior). Las edades U-Pb SHRIMP sobre circón de dos cuerpos graníticos son: 474 ± 6 y 470 ± 10 Ma. Las similitudes estructurales de estos granitos con los leucogranitos emplazados en la parte superior de la Secuencia Principal Himaláyica durante la colisión India-Asia, sugieren un escenario geotectónico parecido. Los magmas félsicos se generaron en la raíz del cabalgamiento, probablemente cerca del arco magmático famatiniano, a lo largo del margen occidental de Gondwana.
