Multiple slope failures associated with neotectonic activity in the Southern Central Andes (37° -37°30's), Patagonia, Argentina

Quaternary tectonic activity in the transition area between the Central and Patagonian Andes is closely associated with an anomalous cluster of rockslides: 19 rockslides with volumes up to 4 × 109 m3 developed in plateau basalts. We divided them into two groups: (A) rockslides related to neotectonic...

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Autores principales: Penna, Ivanna Marina, Folguera, Andrés
Publicado: 2011
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00167606_v123_n9-10_p1880_Penna
http://hdl.handle.net/20.500.12110/paper_00167606_v123_n9-10_p1880_Penna
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spelling paper:paper_00167606_v123_n9-10_p1880_Penna2023-06-08T14:38:51Z Multiple slope failures associated with neotectonic activity in the Southern Central Andes (37° -37°30's), Patagonia, Argentina Penna, Ivanna Marina Folguera, Andrés Argentina Central Andes Climatic conditions Glacial deposits Holocenes Low degree Neotectonics Patagonia Rock avalanche Rock fracturing Rock fragmentation Sliding planes Slope failure Surface exposure age Tectonic activity Triggering factors Deposits Glacial geology Rock bursts Rocks Stratigraphy Landslides fault fold fragmentation landslide neotectonics plateau rock avalanche rock mechanics slope failure stratigraphy Andes Argentina Patagonia Quaternary tectonic activity in the transition area between the Central and Patagonian Andes is closely associated with an anomalous cluster of rockslides: 19 rockslides with volumes up to 4 × 109 m3 developed in plateau basalts. We divided them into two groups: (A) rockslides related to neotectonic activity and (B) rockslides not related to neotectonic activity. Thirteen rockslides, with a total volume of ~10 km3, which lie on either folds or faults, have been displaced parallel to the structures and perpendicular to the valleyaxis, and they exhibit headscarps several kilometersaway from the valley axis. Most of them are larger than 109 m3, and are generally of rock avalanche type with a high degree of crushing of rocks, although local relief in some cases does not exceed 200 m. Nine rockslides with a total volume of 8.9 km3 are related to folds, while four with a total volume of 1.3 km3 are related to faults. The six rockslides not related to neotectonic activity have a totalvolume of 0.25 km3 (of which the largest one accounts for 0.17 km3), and are rotational slides and block topples with a low degree of rock fragmentation, although local relief is up to 400 m. The 3He and 21Ne surface exposure ages for six of these slides, as well as relative age assessment based on stratigraphic relation with glacial deposits and the drainage development on the rockslide deposit, suggest that the rockslide ages spread rather randomly betweenpre-glacial and mid Holocene, discarding climatic conditions as a common triggering factor. The absence of structures that can represent ideal sliding planes shows that rock fracturing due to neotectonic activity is a major conditioning factor for failures and that the magnitude of landslides is strongly controlled by the type of deformation. © 2011 Geological Society of America. Fil:Penna, I.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Folguera, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2011 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00167606_v123_n9-10_p1880_Penna http://hdl.handle.net/20.500.12110/paper_00167606_v123_n9-10_p1880_Penna
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Argentina
Central Andes
Climatic conditions
Glacial deposits
Holocenes
Low degree
Neotectonics
Patagonia
Rock avalanche
Rock fracturing
Rock fragmentation
Sliding planes
Slope failure
Surface exposure age
Tectonic activity
Triggering factors
Deposits
Glacial geology
Rock bursts
Rocks
Stratigraphy
Landslides
fault
fold
fragmentation
landslide
neotectonics
plateau
rock avalanche
rock mechanics
slope failure
stratigraphy
Andes
Argentina
Patagonia
spellingShingle Argentina
Central Andes
Climatic conditions
Glacial deposits
Holocenes
Low degree
Neotectonics
Patagonia
Rock avalanche
Rock fracturing
Rock fragmentation
Sliding planes
Slope failure
Surface exposure age
Tectonic activity
Triggering factors
Deposits
Glacial geology
Rock bursts
Rocks
Stratigraphy
Landslides
fault
fold
fragmentation
landslide
neotectonics
plateau
rock avalanche
rock mechanics
slope failure
stratigraphy
Andes
Argentina
Patagonia
Penna, Ivanna Marina
Folguera, Andrés
Multiple slope failures associated with neotectonic activity in the Southern Central Andes (37° -37°30's), Patagonia, Argentina
topic_facet Argentina
Central Andes
Climatic conditions
Glacial deposits
Holocenes
Low degree
Neotectonics
Patagonia
Rock avalanche
Rock fracturing
Rock fragmentation
Sliding planes
Slope failure
Surface exposure age
Tectonic activity
Triggering factors
Deposits
Glacial geology
Rock bursts
Rocks
Stratigraphy
Landslides
fault
fold
fragmentation
landslide
neotectonics
plateau
rock avalanche
rock mechanics
slope failure
stratigraphy
Andes
Argentina
Patagonia
description Quaternary tectonic activity in the transition area between the Central and Patagonian Andes is closely associated with an anomalous cluster of rockslides: 19 rockslides with volumes up to 4 × 109 m3 developed in plateau basalts. We divided them into two groups: (A) rockslides related to neotectonic activity and (B) rockslides not related to neotectonic activity. Thirteen rockslides, with a total volume of ~10 km3, which lie on either folds or faults, have been displaced parallel to the structures and perpendicular to the valleyaxis, and they exhibit headscarps several kilometersaway from the valley axis. Most of them are larger than 109 m3, and are generally of rock avalanche type with a high degree of crushing of rocks, although local relief in some cases does not exceed 200 m. Nine rockslides with a total volume of 8.9 km3 are related to folds, while four with a total volume of 1.3 km3 are related to faults. The six rockslides not related to neotectonic activity have a totalvolume of 0.25 km3 (of which the largest one accounts for 0.17 km3), and are rotational slides and block topples with a low degree of rock fragmentation, although local relief is up to 400 m. The 3He and 21Ne surface exposure ages for six of these slides, as well as relative age assessment based on stratigraphic relation with glacial deposits and the drainage development on the rockslide deposit, suggest that the rockslide ages spread rather randomly betweenpre-glacial and mid Holocene, discarding climatic conditions as a common triggering factor. The absence of structures that can represent ideal sliding planes shows that rock fracturing due to neotectonic activity is a major conditioning factor for failures and that the magnitude of landslides is strongly controlled by the type of deformation. © 2011 Geological Society of America.
author Penna, Ivanna Marina
Folguera, Andrés
author_facet Penna, Ivanna Marina
Folguera, Andrés
author_sort Penna, Ivanna Marina
title Multiple slope failures associated with neotectonic activity in the Southern Central Andes (37° -37°30's), Patagonia, Argentina
title_short Multiple slope failures associated with neotectonic activity in the Southern Central Andes (37° -37°30's), Patagonia, Argentina
title_full Multiple slope failures associated with neotectonic activity in the Southern Central Andes (37° -37°30's), Patagonia, Argentina
title_fullStr Multiple slope failures associated with neotectonic activity in the Southern Central Andes (37° -37°30's), Patagonia, Argentina
title_full_unstemmed Multiple slope failures associated with neotectonic activity in the Southern Central Andes (37° -37°30's), Patagonia, Argentina
title_sort multiple slope failures associated with neotectonic activity in the southern central andes (37° -37°30's), patagonia, argentina
publishDate 2011
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00167606_v123_n9-10_p1880_Penna
http://hdl.handle.net/20.500.12110/paper_00167606_v123_n9-10_p1880_Penna
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