A petrological and structural assessment of mafic dike swarms in the Patagonian fold-thrust belt during seismic ridge collision

LOBO, CONSTANZA; GUILLOT, MAURICIO GONZÁLEZ; GHIGLIONE, MATÍAS C.

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2022

0895-9811

Between Viedma and San Martín lakes, in an area of 1200 km² that partly covers the Southern Patagonian cordillera and the Miocene-Pliocene extra-Andean basaltic plateaus, mafic dike swarms crop out which have not been studied previously. As a result of mapping on satellite images and in the field more than 1500 dikes were identified. The dikes crop out in a zone between rear-arc calc-alkaline intrusions to the west and tholeiitic-alkaline plateau basalts to the east, within the internal and external fold-thrust belt. In order to understand the genetic relationship between the dikes, other igneous units in the region and the structures of the Andean orogeny, a petrological study (including petrography and geochemistry) and a structural analysis of the dike orientations were carried out. The dikes were emplaced close to the surface (