Evolution actuelle des phénomènes karstiques dans la Cordillera de la Sal (Atacama, Nord Chili)

Abstract

Atacam a, Nord Chili) nÉsuwÉ : Une seconde campagne d'observations a été menée à fin 2005 sur le diapir de sel de la Cordillera de la 5al, sur la bordure ouest du Salar de Atacama, au nord du Chili. Elle faisait suite à une première visite en 1996. Cela nous a permis de constater la lenteur des processus d'érosion dans cette région, l'une des plus arides du globe. Un deuxième réseau de drainage partiellement souterrain a été topographié. Quelques pertes, partiellement obstruées par des dépôts éoliens, ont été relevées.

Candidate cave entrances in a planetary analogue evaporite karst (Cordillera de la Sal, Chile): A remote sensing approach and ground-truth reconnaissance

“…8). The northern one (Z1) is the area with the lowest degree of unexplored CCEs (11, corresponding to 34%), in which explorations for caves has been carried out in earlier expeditions (Salomon, 1995;Sesiano, 1998;Fryer, 2005;Sesiano, 2006Sesiano, , 2009Padovan, 2015, De Waele andPadovan, 2016). The southern area (Z7) on the contrary, was completely unexplored before our 2018 expedition.…”

“…Over the past 30 years, fifteen expeditions by French, American and Italian speleologists have led to the discovery of ca. 50 caves totaling over 22 km in length (Fryer, 2005;Sesiano, 2006Sesiano, , 2009Padovan, 2015, De Waele andPadovan, 2016;De Waele et al, 2019). Most expeditions have taken place close to the San Pedro de Atacama village, where salt outcrops are easily accessible, but in the last 10 years, caves have been discovered also in the central-western part of the CDS, where salt outcrops are more extensive and altitudinal gradients are greater.…”

Holocene evolution of halite caves in the Cordillera de la Sal (Central Atacama, Chile) in different climate conditions

“…There have been several cave expeditions to the Cordillera de la Sal beginning in the early 1990s (Salomon, 1995). These have led to the discovery of about 50 caves totaling over 20 km in length (Fryer, 2005;Sesiano, 2006Sesiano, , 2009Padovan, 2015;De Waele and Padovan, 2016;De Waele et al, 2019). The caves located far from roads and human settlements (over 20 km) are hard to reach, and although being the longest (several km long) and deepest (230 m deep) and most beautiful ones, they are devoid of organic remains (vegetal and animal) being hosted in an area with no vegetation at all.…”

“…Some of the larger caves, with cave passages of 10-m height or even higher, however, might have formed during these wet CAPE periods. Assuming these canyons to have been carved by underground rivers flowing on salt, and knowing that one flood event, with a recurrence in the order of a decade (based on rainfall records of the area over the last century, Ortlieb, 1995 andSesiano, 2006), leads to a dissolution of 2 cm or greater (MEM station of Quebrada Lechuza), a 10-m deep canyon might have formed in less than 5000 years. At this dissolution-erosion rate, smaller caves, such as Lechuza del Campanario, would have formed in a matter of less than 2000 years.…”

Evolution of salt diapir and karst morphology during the last glacial cycle: Effects of sea-level oscillation, diapir and regional uplift, and erosion (Persian Gulf, Iran)

“…Therefore, welldeveloped and mature salt karst is a relatively rare phenomenon worldwide, and information regarding the origin, evolution, and the ages of salt karst areas is limited. Salt karsts occur in the Atacama desert and the neighboring Cordillera de la Sal Mountains in Chile (Fryer, 2005;Sesiano, 2006;De Waele and Forti, 2008;De Waele et al, 2009), in the Cardona Diapir in Spain (Lucha et al, 2008) and in the Vrancea Subcarpathian Hills in Romania (Giurgiu, 2005). The most examined salt karst is the Mt.…”