TY - JOUR
T1 - Depositional processes and growth patterns of isolated oceanic basins
T2 - The Protector and Pirie basins of the Southern Scotia Sea (Antarctica)
AU - Pérez, Lara F.
AU - Maldonado, Andrés
AU - Bohoyo, Fernando
AU - Hernández-Molina, F. Javier
AU - Vázquez, Juan T.
AU - Lobo, F. José
AU - Martos, Yasmina M.
N1 - Funding Information:
This work was funded through projects CTM2008-06386-C01/ANT and CTM2011-30241-C01/ANT, and relates to projects CTM 2012-39599-C03 and IGCP-619. We also acknowledge the projects CTM2011-30241-C02-01/ANT and CTM2011-30241-C02-02/ANT. The corresponding author acknowledges a JAE-Predoctoral fellowship from CSIC as well as affiliations with IEO and IGME institutions. Y. M. M. acknowledges a FPI fellowship at the “Ministerio de Ciencia e Innovación” of Spain. This work was performed in collaboration with the Continental Margins Research Group (CMRG) at Royal Holloway University of London (UK) and was financially supported by the COMPASS consortium. Seismic interpretation was performed using the Seismic Micro-Technology KINGDOM Advance software platform. We also thank the editor, David J.W. Piper, Phil Leat and an anonymous reviewer for their helpful feedback and discussions in publishing this research.
Publisher Copyright:
© 2014 Elsevier B.V.
PY - 2014/11/1
Y1 - 2014/11/1
N2 - Sedimentary processes in small, isolated oceanic basins that form adjacent to continental margins but detached from continents remain poorly understood. This work describes two such basins located in the southern Scotia Sea, the Protector and Pirie basins. We analysed multichannel seismic profiles to interpret morphostructural features and stratigraphy of these basins. Sedimentary stacking patterns and depocentre distribution illustrate basin development patterns. Basal units infill basement depressions formed by the submerged banks of thinned continental crust that abut the basin plains. These lower and middle deposits of the sedimentary record are interpreted as pre- and syn-rift deposits. The laterally extensive upper deposits are interpreted as post-rift deposits. These include five discrete units evident in seismic profiles. A prominent regional reflection referred to as Reflector-c, separates in these upper deposits two sets of seismic units that have recorded major shifts in the dominant sedimentary processes, stacking patterns and paleo-environmental conditions. The most important processes controlling deposition of the older units (those beneath Reflector-c), include down-slope gravity processes that infill depressions created by crustal thinning and seafloor spreading. These occurred under the coeval influence of Circumpolar Deep Water circulation. The major processes influencing younger units (those above Reflector-c) include bottom water circulation of the Circumpolar Deep Water and Weddell Sea Deep Water water masses, which coursed along bathymetric contours of the seafloor. The Reflector-c discontinuity developed concurrently with middle Miocene tectonic changes, which led to the opening and deepening of deep gateways in the South Scotia Ridge. These facilitated overflow of Weddell Sea Deep Water from the Weddell Gyre into the Scotia Sea. This overflow in turn forced the Circumpolar Deep Water northwards. Analysis of the Protector and Pirie basins shows that their tectonic evolution influenced regional deep water circulation patterns in an area that makes a significant cold water contribution to the global conveyor belt system. As a long-term factor controlling basin evolution and sedimentary processes, tectonics events in this region therefore influenced the present day climate system. These results further clarify our understanding of deep, isolated oceanic basins in terms their sedimentologic, climatologic and oceanographic significance.
AB - Sedimentary processes in small, isolated oceanic basins that form adjacent to continental margins but detached from continents remain poorly understood. This work describes two such basins located in the southern Scotia Sea, the Protector and Pirie basins. We analysed multichannel seismic profiles to interpret morphostructural features and stratigraphy of these basins. Sedimentary stacking patterns and depocentre distribution illustrate basin development patterns. Basal units infill basement depressions formed by the submerged banks of thinned continental crust that abut the basin plains. These lower and middle deposits of the sedimentary record are interpreted as pre- and syn-rift deposits. The laterally extensive upper deposits are interpreted as post-rift deposits. These include five discrete units evident in seismic profiles. A prominent regional reflection referred to as Reflector-c, separates in these upper deposits two sets of seismic units that have recorded major shifts in the dominant sedimentary processes, stacking patterns and paleo-environmental conditions. The most important processes controlling deposition of the older units (those beneath Reflector-c), include down-slope gravity processes that infill depressions created by crustal thinning and seafloor spreading. These occurred under the coeval influence of Circumpolar Deep Water circulation. The major processes influencing younger units (those above Reflector-c) include bottom water circulation of the Circumpolar Deep Water and Weddell Sea Deep Water water masses, which coursed along bathymetric contours of the seafloor. The Reflector-c discontinuity developed concurrently with middle Miocene tectonic changes, which led to the opening and deepening of deep gateways in the South Scotia Ridge. These facilitated overflow of Weddell Sea Deep Water from the Weddell Gyre into the Scotia Sea. This overflow in turn forced the Circumpolar Deep Water northwards. Analysis of the Protector and Pirie basins shows that their tectonic evolution influenced regional deep water circulation patterns in an area that makes a significant cold water contribution to the global conveyor belt system. As a long-term factor controlling basin evolution and sedimentary processes, tectonics events in this region therefore influenced the present day climate system. These results further clarify our understanding of deep, isolated oceanic basins in terms their sedimentologic, climatologic and oceanographic significance.
KW - Deep-water circulation
KW - Isolated deep oceanic basins
KW - Scotia sea
KW - Seismic stratigraphy
KW - Tectonics
UR - http://www.scopus.com/inward/record.url?scp=84908465411&partnerID=8YFLogxK
U2 - 10.1016/j.margeo.2014.08.001
DO - 10.1016/j.margeo.2014.08.001
M3 - Article
AN - SCOPUS:84908465411
SN - 0025-3227
VL - 357
SP - 163
EP - 181
JO - Marine Geology
JF - Marine Geology
ER -