The Miocene Torres del Paine Intrusive Complex


Torres del Paine peaks

General view of Torres del Paine peaks, formed by intrusive granitic rocks. (Photo: Lorenzo Albertini).

Geological Period


Main geological interest

Igneous and metamorphic petrology


Región de Magallanes y de la Antárctica Chilena, Chile.
50°58’21.0″S, 73°00’00.0″W

General view of Torres del Paine peaks, formed by intrusive granitic rocks. (Photo: Lorenzo Albertini).

A world class site for the study of structurally controlled emplacement and construction of shallow bimodal laccoliths.

The Torres del Paine Intrusive Complex is a world class site for the study of the emplacement and construction of shallow (upper crustal) layered laccoliths. It crops out extensively (it can be appreciated from base to top) thanks to tectonic uplifting and erosion (mostly glacial), allowing for the study and divulgation of one of the most important processes in geology: mountain building. Detailed geochronological studies have shown that this complex reveals unique clues for understanding the evolution of magmatic chambers and the upwelling of magma towards shallow levels of the upper crust.

General view of the Cuernos del Paine peaks. Light color Miocene (12,5 Ma) granitic rocks of the Torres del Paine Intrusive Complex were emplaced (while molten) into older (Cretaceous, 98-86 Ma), dark color sedimentary country rocks. (Photo: Marcos Aguilar).

The Miocene Torres del Paine Intrusive Complex (12.5 Ma; Michel et al., 2008) is formed by a subhorizontal granitic laccolithic that intruded on top of a mafic body. It extends for more than 12 km with a maximum thickness of 2.5 km. The laccolith is emplaced along a shallow to subhorizontal thrust fault, which is associated with internal folding and faulting developed during an early, pre-intrusion, thin-skinned tectonic phase that deformed the Cretaceous country rock (Halpern, 1973; Michael, 1991). Where the intrusion is thickest, it connects downwards with a subvertical feeder dyke emplaced along an old high-angle reverse fault, thought to be related with a period of thick-skinned tectonic shortening that caused a several kilometer uplift to the western block and consequent erosion of the stratigraphic cover (Skarmeta and Castelli, 1997). The granite intruded as a series of three sheets, each one underplating the previous sheet along the top of the basal Paine Mafic Complex. High-precision U-Pb geochronology in single zircon defines a time frame of 90 ± 30 k.y. for the emplacement of the >2000-m-thick granite laccolith (12.593±0.009 Ma to12.431±0.006 Ma respectively, for the first and last sheet of the laccolith; average growth rate: 0.0005 km3 y, total volume: ~88 km3; Leuthold et al., 2012). These results permit identification of the pulses in a 20 k.y. range, which is markedly lower and much more precise than previous data for crustal magma chambers infill.

This intrusive complex is an extraordinary example of an upper crust mafic and granitic intrusive system that has been studied since early ’70. Recent investigations applied forefront dating analytics to unveil its characteristics regarding the time scale of magmatic pulses and the construction of a shallow laccolith.

Schematic W-E section showing the intrusive relations between the Paine Intrusive Complex (light grey) and the country rocks (black and dark grey, Cerro Toro and Punta Barrosa Formations, respectively). The magma that formed the laccolith ascended through the earth´s crust taking advantage of a preexisting thrust fault, to the west (segmented line). Arrows indicate the relative the sense of movement of the rock blocks. Int.: intrusive granite. Scale in the figure. Modified from Skarmeta and Castelli (1997).

Halpern, M. (1973) ‘Regional Geochronology of Chile South of 50° Latitude’, GSA Bulletin, 84(7), pp. 2407–2422. Available at:<2407:RGOCSO>2.0.CO;2.

Leuthold, J. et al. (2012) ‘Time resolved construction of a bimodal laccolith (Torres del Paine, Patagonia)’, Earth and Planetary Science Letters, 325–326, pp. 85–92. Available at:

Michael, P.J. (1991) ‘Intrusion of basaltic magma into a crystallizing granitic magma chamber: The Cordillera del Paine pluton in southern Chile’, Contributions to Mineralogy and Petrology, 108(4), pp. 396–418. Available at:

Michel, J. et al. (2008) ‘Incremental growth of the Patagonian Torres del Paine laccolith over 90 k.y.’, Geology, 36(6), pp. 459–462. Available at:

Skarmeta, J.J. and Castelli, J.C. (1997) ‘Intrusión sintectónica del Granito de las Torres del Paine, Andes Patagónicos de Chile’, Revista geológica de Chile, 24(1), pp. 55–74.

Felipe Espinoza
Head of the General Geology Department at Chilean Geology and Mining Service- SERNAGEOMIN

Manuel Arenas
National Geological and Mining Service (SERNAGEOMIN), Chile