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The Argentine continental shelf is one of the largest and smoothest siliciclastic shelves in the world. Although it is largely emplaced in a passive continental margin, the southernmost regions are related to transcurrent and active margins respectively associated with the Malvinas Plateau and Scotia Arc. Sea-level fluctuations, sediment dynamics and climatic/oceanographic processes were the most important conditioning factors in the modelling of the shelf, with a minor influence from isostatic and tectonic factors that are more relevant in the southernmost regions. The shelf is shaped by diverse geomorphic features, among which the most significant are four sets of terraces genetically associated to sea-level stillstands during the post-glacial transgression; the final one occurred at around 11 ka and is associated with the Younger Dryas event. The Last Glacial Maximum (LGM) sedimentary sequence is composed of, on average, 5–15 m-thick terrigenous, siliciclastic, relict–palimpsest sands mainly sourced from the Andean region, with minor amounts of bioclast and gravels, resulting from the reworking of pre-transgressive coastal environments.

The Patagonian continental margin records some of the tectonic, sedimentary, climatic, and oceanographic events that participated in the evolution of the Patagonian and south-western Atlantic regions. Those records are essential for fully understanding the geology and biodiversity of Patagonia. Regional geotectonic and morphosedimentary features are characterized by different types of continental margins (passive, transcurrent, and transpressive). In each of them the constituent features (shelf, slope, and rise) acquire particular morphological and sedimentary configurations. Characteristics of the sedimentary sequences and the limiting discontinuities document the different evolutive stages of the margin and intervening major processes. The regional tectonic, palaeoclimatic, and palaeoceanographic events that occurred after the break-up of Gondwana until the Quaternary, which conditioned the morphosedimentary characteristics, are analysed and described here. It is concluded that the region evolved in three major stages, according to the predominance of different factors: (1) a stage dominated by endogene factors, which occurred in Mesozoic times, when the major processes at work were plate tectonics and oceanic opening; (2) a transitional stage, which occurred in the lower Tertiary, when the proto-Atlantic Ocean evolved towards an open sea, and climatic and oceanographic factors became at least as important as tectonic factors; and (3) a stage dominated by exogene factors, which occurred in post-Oligocene times, when the Atlantic Ocean was definitively installed and the circulation of oceanic currents influenced the characteristics of the sedimentary environmentsthis stage ended in the Quaternary when glacioeustatic fluctuations imprinted the present morphosedimentary configuration. Continental Patagónico guarda gran parte de los registros de eventos tectónicos, sedimentarios, climáticos y oceanográficos que participaron en la evolución de la región Patagónica y del Atlántico Suroccidental. Su conocimiento es esencial para comprender cabalmente la geología y biodiversidad de Patagonia. Los rasgos geotectónicos y morfosedimentarios regionales se caracterizan por diferentes tipos de márgenes continentales (pasivo, transcurrente y transpresivo), en cada uno los cuales sus elementos constituyentes, la plataforma, el talud y la emersión, adquieren configuraciones morfológicas y sedimentarias particulares. Las características de las secuencias estratigráficas y sus discontinuidades documentan las distintas etapas de evolución del margen y los procesos mayores intervinientes. Se analizan y describen los eventos tectónicos, palaeoclimáticos y palaeoceanográficos de extensión regional que caracterizaron a la región desde la apertura de Gondwana hasta el Cuaternario y condicionaron sus aspectos morfosedimentarios. Se concluye que la región evolucionó en tres etapas mayores de acuerdo al predominio de diferentes factores: 1) etapa dominada por factores endógenos, ocurrida en tiempos Mesozoicos, cuando los procesos mayores ...

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