Impact of the 1960 major subduction earthquake in Northern Patagonia (Chile, Argentina)

EMMANUEL CHAPRON; DANIEL ARIZTEGUI; SANDOR MULSOW; GUSTAVO VILLAROSA; MARIO PINO; VALERIA OUTES; ETIENNE JUVIGNIE; ERNESTO CRIVELLI

QUATERNARY INTERNATIONAL

Elsevier

Lugar: Amsterdam; Año: 2006 vol. 158 p. 58 - 71

1040-6182

The recent sedimentation processes in four contrasting lacustrine and marine basins of Northern Patagonia are documented by highresolution seismic reflection profiling and short cores at selected sites in deep lacustrine basins. The regional correlation of the cores is provided by the combination of 137Cs dating in lakes Puyehue (Chile) and Frý´as (Argentina), and by the identification of Cordon Caulle 1921–22 and 1960 tephras in lakes Puyehue and Nahuel Huapi (Argentina) and in their catchment areas. This event stratigraphy allows correlation of the formation of striking sedimentary events in these basins with the consequences of the May–June 1960 earthquakes and the induced Cordon Caulle eruption along the Liquin˜ e-Ofqui Fault Zone (LOFZ) in the Andes. While this catastrophe induced a major hyperpycnal flood deposit of ca. 3
106m3 in the proximal basin of Lago Puyehue, it only triggered an unusual organic rich layer in the proximal basin of Lago Frý´as, as well as destructive waves and a large sub-aqueous slide in the distal basin of Lago Nahuel Huapi. A very recent mega-turbidite in the two distal basins of Reloncavi fjord located close to the LOFZ suggests that 1960 co-seismic movements in this area may have triggered the remobilization of ca. 187
106m3 of marine sediments.137Cs dating in lakes Puyehue (Chile) and Frý´as (Argentina), and by the identification of Cordon Caulle 1921–22 and 1960 tephras in lakes Puyehue and Nahuel Huapi (Argentina) and in their catchment areas. This event stratigraphy allows correlation of the formation of striking sedimentary events in these basins with the consequences of the May–June 1960 earthquakes and the induced Cordon Caulle eruption along the Liquin˜ e-Ofqui Fault Zone (LOFZ) in the Andes. While this catastrophe induced a major hyperpycnal flood deposit of ca. 3
106m3 in the proximal basin of Lago Puyehue, it only triggered an unusual organic rich layer in the proximal basin of Lago Frý´as, as well as destructive waves and a large sub-aqueous slide in the distal basin of Lago Nahuel Huapi. A very recent mega-turbidite in the two distal basins of Reloncavi fjord located close to the LOFZ suggests that 1960 co-seismic movements in this area may have triggered the remobilization of ca. 187
106m3 of marine sediments. r 2006 Elsevier Ltd and INQUA. All rights reserved.2006 Elsevier Ltd and INQUA. All rights reserved.