Please use this identifier to cite or link to this item: http://dlib.scu.ac.ir/handle/1956/4530
Title: Hemipelagic deposits on the Mendeleev and northwestern Alpha submarine Ridges in the Arctic Ocean: acoustic stratigraphy, depositional environment and an inter-ridge correlation calibrated by the ACEX results
subject: Arctic Ocean;Mendeleev and Alpha Ridges;Depositional environment;Acoustic stratigraphy;Paleocirculation;Tectonics;Inter-ridge correlation;VDP::Mathematics and natural science: 400
Publisher: Springer
Description: The first high resolution multichannel seismic data from the Mendeleev and Alpha Ridges in the Arctic Ocean have been used to investigate the depositional history, and compare acoustic stratigraphies of the three main sub-marine ridges (Mendeleev, Alpha and Lomonosov) in the polar ocean. Acoustic basement on the Mendeleev Ridge is covered by a ~0.6–0.8 s thick sediment drape over highs and up to 1.8 s within grabens. A pronounced angular discordance at 0.18–0.23 s below the seafloor along the middle to upper slopes divides the succession into an upper, undisturbed, uniformly thick, hemipelagic drape (Unit M1) and a partially truncated lower unit (Unit M2) characterized by strong reflection bands. Unit M2 is thicker in intra-ridge grabens and includes three sub-units with abundant debris flows in the uppermost subunit (M2a). The discordance between Units M1 and M2 most likely relates to instability along the middle to upper slopes and mass wasting, triggered by tectonic activity. The scars were further smoothed by bottom current erosion. We observe comparable acoustic stratigraphy and discordant relationships on the investigated northwestern part of Alpha Ridge. Similarly, on the central Lomonosov Ridge, Paleocene and younger sediments sampled by scientific drilling include an uppermost ~0.2 s thick drape overlying, highly reflective deposits with an angular unconformity confined to the upper slope on both sides of the ridge. Sediment instability on the three main ridges was most likely generated by a brief phase of tectonic activity (~14.5–22 Ma), coinciding with enhanced bottom circulation. These events are coeval with the initial opening of the Fram Strait. The age of the oldest sediments above acoustic basement on the Mendeleev- and west-central Alpha Ridges is estimated to be 70–75 Ma.
Journal Article
publishedVersion
URI: https://bora.uib.no/handle/1956/4530
More Information: Marine Geophysical Researches 31: 149-171
0025-3235
http://hdl.handle.net/1956/4530
10.1007/s11001-010-9094-9
Appears in Collections:Department of Earth Science

Files in This Item:
Click on the URI links for accessing contents.
Title: Hemipelagic deposits on the Mendeleev and northwestern Alpha submarine Ridges in the Arctic Ocean: acoustic stratigraphy, depositional environment and an inter-ridge correlation calibrated by the ACEX results
subject: Arctic Ocean;Mendeleev and Alpha Ridges;Depositional environment;Acoustic stratigraphy;Paleocirculation;Tectonics;Inter-ridge correlation;VDP::Mathematics and natural science: 400
Publisher: Springer
Description: The first high resolution multichannel seismic data from the Mendeleev and Alpha Ridges in the Arctic Ocean have been used to investigate the depositional history, and compare acoustic stratigraphies of the three main sub-marine ridges (Mendeleev, Alpha and Lomonosov) in the polar ocean. Acoustic basement on the Mendeleev Ridge is covered by a ~0.6–0.8 s thick sediment drape over highs and up to 1.8 s within grabens. A pronounced angular discordance at 0.18–0.23 s below the seafloor along the middle to upper slopes divides the succession into an upper, undisturbed, uniformly thick, hemipelagic drape (Unit M1) and a partially truncated lower unit (Unit M2) characterized by strong reflection bands. Unit M2 is thicker in intra-ridge grabens and includes three sub-units with abundant debris flows in the uppermost subunit (M2a). The discordance between Units M1 and M2 most likely relates to instability along the middle to upper slopes and mass wasting, triggered by tectonic activity. The scars were further smoothed by bottom current erosion. We observe comparable acoustic stratigraphy and discordant relationships on the investigated northwestern part of Alpha Ridge. Similarly, on the central Lomonosov Ridge, Paleocene and younger sediments sampled by scientific drilling include an uppermost ~0.2 s thick drape overlying, highly reflective deposits with an angular unconformity confined to the upper slope on both sides of the ridge. Sediment instability on the three main ridges was most likely generated by a brief phase of tectonic activity (~14.5–22 Ma), coinciding with enhanced bottom circulation. These events are coeval with the initial opening of the Fram Strait. The age of the oldest sediments above acoustic basement on the Mendeleev- and west-central Alpha Ridges is estimated to be 70–75 Ma.
Journal Article
publishedVersion
URI: https://bora.uib.no/handle/1956/4530
More Information: Marine Geophysical Researches 31: 149-171
0025-3235
http://hdl.handle.net/1956/4530
10.1007/s11001-010-9094-9
Appears in Collections:Department of Earth Science

Files in This Item:
Click on the URI links for accessing contents.
Title: Hemipelagic deposits on the Mendeleev and northwestern Alpha submarine Ridges in the Arctic Ocean: acoustic stratigraphy, depositional environment and an inter-ridge correlation calibrated by the ACEX results
subject: Arctic Ocean;Mendeleev and Alpha Ridges;Depositional environment;Acoustic stratigraphy;Paleocirculation;Tectonics;Inter-ridge correlation;VDP::Mathematics and natural science: 400
Publisher: Springer
Description: The first high resolution multichannel seismic data from the Mendeleev and Alpha Ridges in the Arctic Ocean have been used to investigate the depositional history, and compare acoustic stratigraphies of the three main sub-marine ridges (Mendeleev, Alpha and Lomonosov) in the polar ocean. Acoustic basement on the Mendeleev Ridge is covered by a ~0.6–0.8 s thick sediment drape over highs and up to 1.8 s within grabens. A pronounced angular discordance at 0.18–0.23 s below the seafloor along the middle to upper slopes divides the succession into an upper, undisturbed, uniformly thick, hemipelagic drape (Unit M1) and a partially truncated lower unit (Unit M2) characterized by strong reflection bands. Unit M2 is thicker in intra-ridge grabens and includes three sub-units with abundant debris flows in the uppermost subunit (M2a). The discordance between Units M1 and M2 most likely relates to instability along the middle to upper slopes and mass wasting, triggered by tectonic activity. The scars were further smoothed by bottom current erosion. We observe comparable acoustic stratigraphy and discordant relationships on the investigated northwestern part of Alpha Ridge. Similarly, on the central Lomonosov Ridge, Paleocene and younger sediments sampled by scientific drilling include an uppermost ~0.2 s thick drape overlying, highly reflective deposits with an angular unconformity confined to the upper slope on both sides of the ridge. Sediment instability on the three main ridges was most likely generated by a brief phase of tectonic activity (~14.5–22 Ma), coinciding with enhanced bottom circulation. These events are coeval with the initial opening of the Fram Strait. The age of the oldest sediments above acoustic basement on the Mendeleev- and west-central Alpha Ridges is estimated to be 70–75 Ma.
Journal Article
publishedVersion
URI: https://bora.uib.no/handle/1956/4530
More Information: Marine Geophysical Researches 31: 149-171
0025-3235
http://hdl.handle.net/1956/4530
10.1007/s11001-010-9094-9
Appears in Collections:Department of Earth Science

Files in This Item:
Click on the URI links for accessing contents.