RT Journal Article
T1 Present-day strain field on the South American slab underneath the Sandwich Plate (Southern Atlantic Ocean): A kinematic model
A1 Giner Robles, Jorge Luis
A1 Pérez López, Raúl
A1 Rodríguez Pascua, Miguel Angel
A1 Martínez Díaz, José Jesús
A1 González Casado, J.M.
AB This work analyses the present-day principal strain orientation on the downgoing slab of the South America Plate (SAM) beneath the Sandwich Plate (SAND). The strain regime was deduced from the study of 331 earthquake focal mechanism solutions examined by fault population analysis methods. In the slab, the maximum horizontal shortening direction (ey) rotates in trend in a clockwise direction from NE in the north, to SE in the south. Based on this rotation, three different areas were defined according to the prevailing focal mechanism type: (1) the North Zone, with ey oriented N058°E and reverse and strike-slip focal mechanisms; (2) the Central Zone, with only reverse focal mechanisms and ey striking N080°E; and (3) the South Zone, with ey oriented N1068E and reverse and strike-slip focal mechanisms. The strain field in the North Zone of the SAND involves decoupling of the slab at approximately 70 km depth. In contrast, the South Zone edge slab exhibits no decoupling and it exhibits different geometry (hook-like shaped) from the North Zone. Finally, we define the dextral strike-slip component acting at the South Sandwich Fracture Zone (SSFZ), according to focal mechanism solutions and the regional tectonic configuration.
PB The Geological Society
SN 0305-8719; ESSN: 2041-4927
YR 2009
FD 2009
LK https://hdl.handle.net/20.500.14352/52897
UL https://hdl.handle.net/20.500.14352/52897
LA eng
NO Spanish Interministerial Commission of Science and Education
DS Docta Complutense
RD 10 abr 2025