Descripción: Three of the biggest barrier spits of Argentina are studied in order to determine the relationship between the coastal planform and littoral dynamics. The studied landforms are the spit of Cabo San Antonio of an age of the 5800 years BP, the north spit of Caleta Valdés with a maximum age of approximately 5700 years BP and El Páramo spit of San Sebastián bay with an inferred age of approximately 6000 years BP. The orientation regarding the coastal planform of the three spits, allows to establish the relationship between landforms and coastal dynamics, being obtained the predominant waves that gave origin to them. Also the possible consequences for the modification or erosion of these landforms, that they would take to the disappearance of coastal environments of significant ecological value and the submergence of some adjacent areas; just as it would happen in Caleta Valdés.

Descripción: Deception Island (South Shetlands, Antarctica) is one of the most active volcanoes in Antarctica, having erupted recently in 1967, 1969 and 1970, damaging scientific stations on the island. It is also seismically very active. The island has attracted the attention of many researchers as it constitutes an undisturbed natural laboratory to study seismo-volcanic events and how they affect landscape modelling and evolution. One of the most remarkable geological and geomorphological features on Deception Island is the linearity of its easternmost coastal landform, the origin of which remains unknown. Some answers, based on presence of strike-slip fault or on the ice cap and beach geomorphological dynamics, have been reported in the literature. Our new work provides several indications of the existence of a dip-slip submarine fault, parallel to the coast (NNW-SSE), which suggests a tectonic origin for this morphological feature. Uplifted marine terraces, incision of a fluvial network over the ice cap, normal faulting parallel to the coast in the north and south rock heads bounding the beach and sharp shelf-break with rather constant slope, constitute some of this evidence. Terrace uplift and fluvial channel incision decreasing southward from Macaroni Point, indicates possible tilt movement across this inferred fault plane. © Antarctic Science Ltd.