TY - JOUR
T1 - Unveiling Powell Basin’s tectonic domains and understanding its abnormal magnetic anomaly signature. Is heat the key?
AU - Catalán, M.
AU - Martos, Y.M.
AU - Galindo-Zaldivar, J.
AU - Perez, L.F.
AU - Bohoyo, F.
N1 - Funding Information:
This study has been funded through project RTI 2018–099615-B-100 entitled “Estructura Litosférica y Geodinámica de Powell-Drake-Bransfield Rift” under the umbrella of the Programa Estatal de I + D + i Orientada a los Retos de la Sociedad of the Spanish Ministry of Science. JG, FB, and LP participation has been funded through project CTM 2017–89711-C2-2-P entitled “Timing and main tectonic processes involved in the onset and evolution of the Antarctic Circumpolar Current (ACC): development of continental margins and oceanic basins” under the umbrella of the Programa Estatal de I + D + i of the Spanish Ministry of Science.
Publisher Copyright:
© Copyright © 2020 Catalán, Martos, Galindo-Zaldivar, Perez and Bohoyo.
PY - 2020/10/8
Y1 - 2020/10/8
N2 - Rifting of continental lithosphere leading to oceanic basins is a complex process conditioned by different factors such as the rheology and thermal structure of the underlying lithosphere, as well as underlying asthenospheric dynamics. All these processes, which finally lead to oceanic domains, can better be recognized in small oceanic basins. Powell Basin is a small oceanic basin bounded to the north by the South Scotia Ridge, to the east by the South Orkney Microcontinent, and to the west by the Antarctic Peninsula. It was formed between the Oligocene and Miocene, however, its age is not well defined, among other reasons due to the small amplitude of its spreading magnetic anomalies. This basin is an ideal framework to analyze the different rifting and spreading phases, which leads from continental crust to the formation of an oceanic domain through different extensional regimes. To identify the different boundaries during the formation of Powell Basin from the beginning of the rifting until the end of the spreading, we use different data sources: magnetic, gravity, multichannel seismic profiles and bathymetry data. We use seismic and bathymetry data to estimate the Total Tectonic Subsidence. Total Tectonic Subsidence has proven to be useful to delineate the different tectonic regimes present from early rifting to the formation of oceanic seafloor. This result together with magnetic data has been used to delimit the oceanic domain and compare with previous authors’ proposals. This method could be applied in any other basin or margin to help delimiting its boundaries. Finally, we analyze the role that an asthenospheric branch intruding from the Scotia Sea played in the evolution of the magnetic anomaly signature on an oceanic basin.
AB - Rifting of continental lithosphere leading to oceanic basins is a complex process conditioned by different factors such as the rheology and thermal structure of the underlying lithosphere, as well as underlying asthenospheric dynamics. All these processes, which finally lead to oceanic domains, can better be recognized in small oceanic basins. Powell Basin is a small oceanic basin bounded to the north by the South Scotia Ridge, to the east by the South Orkney Microcontinent, and to the west by the Antarctic Peninsula. It was formed between the Oligocene and Miocene, however, its age is not well defined, among other reasons due to the small amplitude of its spreading magnetic anomalies. This basin is an ideal framework to analyze the different rifting and spreading phases, which leads from continental crust to the formation of an oceanic domain through different extensional regimes. To identify the different boundaries during the formation of Powell Basin from the beginning of the rifting until the end of the spreading, we use different data sources: magnetic, gravity, multichannel seismic profiles and bathymetry data. We use seismic and bathymetry data to estimate the Total Tectonic Subsidence. Total Tectonic Subsidence has proven to be useful to delineate the different tectonic regimes present from early rifting to the formation of oceanic seafloor. This result together with magnetic data has been used to delimit the oceanic domain and compare with previous authors’ proposals. This method could be applied in any other basin or margin to help delimiting its boundaries. Finally, we analyze the role that an asthenospheric branch intruding from the Scotia Sea played in the evolution of the magnetic anomaly signature on an oceanic basin.
KW - asthenospheric channel
KW - Bouguer gravity anomaly
KW - continent-ocean boundary
KW - heat flow
KW - magnetic anomaly
KW - total tectonic subsidence
UR - http://www.scopus.com/inward/record.url?scp=85093946305&partnerID=8YFLogxK
U2 - 10.3389/feart.2020.580675
DO - 10.3389/feart.2020.580675
M3 - Article
AN - SCOPUS:85093946305
SN - 2296-6463
VL - 8
JO - Frontiers in Earth Science
JF - Frontiers in Earth Science
M1 - 580675
ER -