Skip to Main Content
Book Chapter

Late Pliocene mega debris flow deposit and related fluid escapes identified on the Antarctic Peninsula continental margin by seismic reflection data analysis

By
P. Diviacco
P. Diviacco
Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Borgo Grotta Gigante 42/C, 1-34010, Sgonico, TS, Italy;
Search for other works by this author on:
M. Rebesco
M. Rebesco
Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Borgo Grotta Gigante 42/C, 1-34010, Sgonico, TS, Italy;
Search for other works by this author on:
A. Camerlenghi
A. Camerlenghi
Departament d’Estratigrafia, P. i Geociencies Marines, Universitat de Barcelona, C/ Marti i Franqws, s/n, E-08028, Barcelona, Spain;
Search for other works by this author on:
Published:
January 01, 2016

Abstract

We have obtained improved images of a debris flow deposit through the reprocessing of multichannel seismic reflection data between Drifts 6 and 7 of the continental rise of the Pacific margin of the Antarctic Peninsula. The reprocessing, primarily aimed at the reduction of noise, relative to amplitude preservation, deconvolution, also included accurate velocity analyses. The deposit is dated as upper Pliocene (nearly 3.0 Ma) via correlation to Sites 1095 and 1096 of the Ocean Drilling Program (ODP) Leg 178. The estimated volume is about 1800 km3 and the inferred provenance from the continental slope implies a run out distance exceeding 250 km. The dramatic mass-wasting event that produced this deposit, unique in the sedimentary history of this margin, is related to widespread late Pliocene margin erosion. This was associated with a catastrophic continental margin collapse, following the Antarctic ice sheet expansion in response to global cooling. The seismic data analysis also allowed us to identify diffractions and amplitude anomalies interpreted as expressions of sedimentary mounds at the seafloor overlying narrow high-velocity zones that we interpret as conduits of fluid expulsion hosting either methane hydrates or authigenic carbonates. Fluid expulsion was triggered by loading of underlying sediments by the debris flow deposits and may have continued until today by input of fluids from sediment compaction following the deep diagenesis of biogenic silica.

You do not currently have access to this article.

Figures & Tables

Contents

Society of Exploration Geophysicists Geophysics Reprint Series

Seismic Diffraction

Kamil Klem-Musatov
Kamil Klem-Musatov
Search for other works by this author on:
Henning Hoeber
Henning Hoeber
Search for other works by this author on:
Michael Pelissier
Michael Pelissier
Search for other works by this author on:
Tijmen Jan Moser
Tijmen Jan Moser
Search for other works by this author on:
Society of Exploration Geophysicists
Volume
30
ISBN electronic:
9781560803188
Publication date:
January 01, 2016

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal