TY - JOUR

T1 - Depositional Evolution of the Western Amundsen Basin, Arctic Ocean

T2 - Paleoceanographic and Tectonic Implications

AU - Castro, Carlos F.

AU - Knutz, Paul C.

AU - Hopper, John R.

AU - Funck, Thomas

N1 - Funding Information: One of the authors (C. F. C.) was supported by a scholarship from the Consejo Nacional de Ciencia y Tecnología (CONACYT) in Mexico. Data acquisition was funded by the Continental Shelf Project of the Kingdom of Denmark. Special thanks to Lars Kjærgaard for his assistance with the loading of multichannel seismic reflection data and GEUS-IT for all their technical support. We thank two anonymous reviewers and Bernard Coakley for constructive reviews of the manuscript that led to substantial revisions and improvements. This paper is published with permission from the Geological Survey of Denmark and Greenland. The LOMROG seismic data presented in this paper are permanently archived at the Geological Survey of Denmark and Greenland (GEUS). Information regarding access to data and databases archived at GEUS is available at https://www.geus.dk. The AWI seismic data are owned and archived by the Alfred Wegener Institute (AWI). Information regarding their data can be obtained from the AWI Geophysics Department (https://www. awi.de/en/science/geosciences/geophysics.html). Funding Information: One of the authors (C. F. C.) was supported by a scholarship from the Consejo Nacional de Ciencia y Tecnología (CONACYT) in Mexico. Data acquisition was funded by the Continental Shelf Project of the Kingdom of Denmark. Special thanks to Lars Kjærgaard for his assistance with the loading of multichannel seismic reflection data and GEUS-IT for all their technical support. We thank two anonymous reviewers and Bernard Coakley for constructive reviews of the manuscript that led to substantial revisions and improvements. This paper is published with permission from the Geological Survey of Denmark and Greenland. The LOMROG seismic data presented in this paper are permanently archived at the Geological Survey of Denmark and Greenland (GEUS). Information regarding access to data and databases archived at GEUS is available at https://www.geus.dk. The AWI seismic data are owned and archived by the Alfred Wegener Institute (AWI). Information regarding their data can be obtained from the AWI Geophysics Department (https://www.awi.de/en/science/geosciences/geophysics.html). Publisher Copyright: ©2018. The Authors.

PY - 2018/12

Y1 - 2018/12

N2 - A new stratigraphic model and estimated sedimentation rates of the western Amundsen Basin, Arctic Ocean, are presented based on multichannel seismic reflection data, seismic refraction data, magnetic data, and integrated with the sedimentary sequence from the central Arctic Ocean, obtained during the Arctic Coring Expedition. This places new constraints on the postbreakup Cenozoic depositional history of the basin, the adjacent Lomonosov Ridge, and improves the understanding of the tectonic, climatic, and oceanographic conditions in the central Arctic region. Four distinct phases of basin development are proposed. During the Paleocene-mid-Oligocene, high sedimentation rates are linked to terrestrial input and increased pelagic deposition in a restricted basin. Deposition of sedimentary wedges and mass transport into marginal depocenters reflect a period of tectonic instability linked to compression associated with the Eurekan Orogeny in the Arctic. During the late Oligocene-early Miocene, widespread passive infill associated with hemipelagic deposition reflects a phase of limited tectonism, most likely in a freshwater estuarine setting. During the middle Miocene, mounded sedimentary buildups along the Lomonosov Ridge suggest the onset of geostrophic bottom currents that likely formed in response to a deepening and widening of the Fram Strait beginning around 18 Ma. In contrast, the Plio-Pleistocene stage is characterized by erosional features such as scarps and channels adjacent to levee accumulations, indicative of a change to a higher-energy environment. These deposits are suggested to be partly associated with dense shelf water-mass plumes driven by supercooling and brine formation over the northern Greenland continental shelf.

AB - A new stratigraphic model and estimated sedimentation rates of the western Amundsen Basin, Arctic Ocean, are presented based on multichannel seismic reflection data, seismic refraction data, magnetic data, and integrated with the sedimentary sequence from the central Arctic Ocean, obtained during the Arctic Coring Expedition. This places new constraints on the postbreakup Cenozoic depositional history of the basin, the adjacent Lomonosov Ridge, and improves the understanding of the tectonic, climatic, and oceanographic conditions in the central Arctic region. Four distinct phases of basin development are proposed. During the Paleocene-mid-Oligocene, high sedimentation rates are linked to terrestrial input and increased pelagic deposition in a restricted basin. Deposition of sedimentary wedges and mass transport into marginal depocenters reflect a period of tectonic instability linked to compression associated with the Eurekan Orogeny in the Arctic. During the late Oligocene-early Miocene, widespread passive infill associated with hemipelagic deposition reflects a phase of limited tectonism, most likely in a freshwater estuarine setting. During the middle Miocene, mounded sedimentary buildups along the Lomonosov Ridge suggest the onset of geostrophic bottom currents that likely formed in response to a deepening and widening of the Fram Strait beginning around 18 Ma. In contrast, the Plio-Pleistocene stage is characterized by erosional features such as scarps and channels adjacent to levee accumulations, indicative of a change to a higher-energy environment. These deposits are suggested to be partly associated with dense shelf water-mass plumes driven by supercooling and brine formation over the northern Greenland continental shelf.

KW - Arctic Ocean

KW - brine formation

KW - channel-levee deposits

KW - contourite drifts

KW - Eurekan compression

KW - seismic stratigraphy

UR - http://www.scopus.com/inward/record.url?scp=85058411607&partnerID=8YFLogxK

U2 - 10.1029/2018PA003414

DO - 10.1029/2018PA003414

M3 - Journal article

AN - SCOPUS:85058411607

VL - 33

SP - 1357

EP - 1382

JO - Paleoceanography and Paleoclimatology

JF - Paleoceanography and Paleoclimatology

SN - 0883-8305

IS - 12

ER -