Estimates of paleo-crustal thickness at Cerro Aconcagua (Southern Central Andes) from detrital proxy-records: Implications for models of continental arc evolution

The Central Andes represent the archetypical Cordilleran orogenic system, with a well-developed continental volcanic arc and some of thickest crust on Earth. Yet relative contributions shortening magmatic additions to crustal thickening remain difficult quantify, which hinders understanding processes evolution in arcs. Cerro Aconcagua, highest mountain Americas relict Miocene stratovolcano resting 55 km-thick crust, is ideal natural laboratory address this issue subduction-related arcs because it preserves multi-million year record magmatism deformation within Aconcagua fold-thrust belt. Estimates paleo-crustal thickness can be made using geochemistry rocks, or minerals crystallized them. This study applies geochemical proxy approach for estimates detrital syntectonic deposits Santa Maria Conglomerate derived from reconstruct at latitude. Detrital zircon trace-element data ashes intercalated conglomerate, combined previously published data, indicate thicknesses ?35 km ca. 38 Ma ?44 12 Ma, requiring ?11 after achieve present-day ?55 km. In absence significant since 10 location, we show that more than half corresponding 2 uplift, was achieved by shortening. Our also reveals differences between southern speculate may due southward flow during last ?20 My.