Charles Darwin and the first scientific observations on the patagonian shingle formation (Rodados Patagónicos)

Abstract

The Rodados Patagónicos is one of the most intriguing lithostratigraphic unitsin the Late Cenozoic of Patagonia. Charles Darwin named these gravels as the "Patagonian Shingle Formation", when he discovered them during his trip to Patagonia on board HMS Beagle in 1832. According to the prevailing paradigm ofthe time, he assigned these deposits to a giant transgression during the GreatUniversal Déluge epoch, considering that their formation was related to waveaction along the beach in ancient times. The name of Rodados Patagónicos, as they are generally known in the Argentine geological literature, is usually confusing since it has been applied to a wide number of geological units of multiple origin and age. Many authors have discussed the nature and origin of these gravels, considering them to have been formed by piedmont, alluvial, colluvial, glaciofluvial, and/or marine processes. Today, it is accepted that the term Rodados Patagónicos includes gravel deposits of varied nature and age, perhaps with a prevalence of piedmont genesis in northern Patagonia and glaciofluvial dynamics in southern Patagonia and Tierra del Fuego.