Publications des scientifiques de l'IRD

Calvès G., Auguy C., de Lavaissière L., Brusset S., Calderon Y., Baby Patrice. (2017). Fore-arc seafloor unconformities and geology : insight from 3-D seismic geomorphology analysis, Peru. Geochemistry Geophysics Geosystems, 18 (8), p. 3062-3077. ISSN 1525-2027.

Titre du document
Fore-arc seafloor unconformities and geology : insight from 3-D seismic geomorphology analysis, Peru
Année de publication
2017
Type de document
Article référencé dans le Web of Science WOS:000411196000013
Auteurs
Calvès G., Auguy C., de Lavaissière L., Brusset S., Calderon Y., Baby Patrice
Source
Geochemistry Geophysics Geosystems, 2017, 18 (8), p. 3062-3077 ISSN 1525-2027
New 3-D seismic data collected over 4870 km(2) in the 3 degrees 45S-12 degrees 30S Peruvian segment of the East Pacific subduction system image seafloor erosional surfaces that can be mapped across the fore-arc basins. Fore-arc basins experience various stresses, from their base where basal tectonic erosion acts to the seafloor which is influenced by aerial, shallow, and deep water currents driven by waves or thermohaline oceanic currents. Previously there has been little interest in stresses on the upper layer and there is a lack of documentation of unconformities and the erosive processes in certain bathymetric domains in fore-arc basins. We address this with the study of examples sourced from 3-D seismic reflection surveys of the seafloor offshore Peru. Unconformities occur in two distinctive bathymetric domains associated with the continental shelf and the upper slope of the margin. Identification and characterization of unconformity surfaces yield estimates of the amount of erosion at the modern seafloor that range from 18 to 100%. Regional physical oceanography allows us to calibrate potential candidates for these two distinctive domains. The first control on erosion is the dynamics of deep to intermediate oceanic currents related to the Humboldt-Peru Chile water masses, while the second is wave action in the shallower erosional surfaces. This study illustrates the unseen landscape of the fore-arc basins of South America and helps to highlight the importance of erosive surficial processes in subduction landscapes.
Plan de classement
Géologie et formations superficielles [064] ; Géophysique interne [066]
Description Géographique
PEROU ; PACIFIQUE ; HUMBOLDT COURANT
Localisation
Fonds IRD [F B010071032]
Identifiant IRD
fdi:010071032
Contact