The North-Wetern boundaries of the Caribean and Scotia Ar

LODOLO E.; MENICHETTI, M.; TASSONE A.; GIUNTA, G.

Malargüe. Mendoza

Otro; Tercer Encuentro Científico del ICES; 2007

International Centre for Earth Sciences (ICES)

The Caribbean and Scotia Arcs represent two of the most striking features of our planet, because immediately recognizable in any geographic map (Fig. 1). They are respectively located between North and South America, and South America and Antarctica, joining the North American Cordillera to the Andes, and the Andes to the Antarctic Peninsula orogenic belt. The two Arcs are nearly identical in size, and present impressive morphological and structural analogies, mostly occurring along their plate boundaries. The Caribbean Arc differs from the Scotia Arc with the presence of the Central American land bridge. Their tectonic evolution can be related to the relative motion between the two pairs of land masses, which strongly conditioned the morphology and structure of their margins both superficially and at shallow and deep levels. In the last ten years, a series of field geological and geophysical campaigns have been performed by a group of Italian and Argentinean researchers along the western segments of both the North America-Caribbean (Polochic-Motagua transform system) and South America-Scotia plate boundaries (Magallanes-Fagnano transform system), in order to delineate their main morphological and structural characteristics, and analyze the tectonic mechanisms which conditioned their development through the geological time. Here we describe the principal features of both the Polochic-Motagua transform system, which traverses broadly E-W Guatemala, and the Magallanes-Fagnano transform system, which runs across the Tierra del Fuego Island, highlighting the most important geological and geophysical analogies associated to these two tectonic lineaments.