The nature of the acoustic basement on Mendeleev and northwestern Alpha ridges, Arctic Ocean

Bruvoll, Vibeke; Kristoffersen, Yngve; Coakley, Bernard; Hopper, John R.; Planke, Sverre; Kandilarov, Aleksandre

doi:10.1016/j.tecto.2011.10.015

Cited by 59 publications

(41 citation statements)

References 69 publications

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“…The median values are calculated at 108 stations for which the number of velocity-depth samples is at least five, which ensures that the median statistic is not biased by possible outliers. This criterion corresponds to a minimum sedimentary thickness of about 1.5 km, and thereby excludes areas of the Northwind and Alpha-Mendeleev ridges where the succession is relatively thin and predominantly unlithified (Bruvoll et al 2012;Hegewald & Jokat 2013). The average of the median ratios for the 108 stations is 1.01, confirming that the regional reference model is a reasonably unbiased estimate of the overall sample set, but the 2-D spatial variation of the median ratios is strikingly nonrandom.…”

Section: Regional Velocity-depth Modelmentioning

confidence: 72%

“…The prism thins to the north and west with increasing distance from the slope, and it is generally less than 1 km in thickness over the Northwind and Alpha-Mendeleev ridges (Bruvoll et al 2012;Hegewald & Jokat 2013). The sediment provenance is diverse, and it includes the Chukotka magmatic belt, the Brooks Range orogenic belt, the Ellesmerian orogenic belt, the Canadian craton, the Arctic Platform and volcanics associated with the Alpha Ridge (Houseknecht & Bird 2011).…”

Section: Geological Synopsismentioning

confidence: 99%

“…Another possibility is that high-velocity volcanic units could be incorporated within the sedimentary succession. Using seismic reflection and refraction data, Bruvoll et al (2012) interpreted the existence of multiple lava flows over voluminous tuff deposits and/or possible sediments along Mendeleev and northwestern Alpha ridges. However, the results for subregion 5 in the present study demonstrate that the velocity-depth samples associated with the Alpha-Mendeleev magnetic domain are faster than the regional average throughout the bulk of the succession (Fig.…”

Section: Associations With Geothermal Heat Flow and Crustal Typementioning

confidence: 99%

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Seismic velocities within the sedimentary succession of the Canada Basin and southern Alpha-Mendeleev Ridge, Arctic Ocean: evidence for accelerated porosity reduction?

Shimeld¹,

Li²,

Chian³

et al. 2015

Geophysical Journal International

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S U M M A R YThe Canada Basin and the southern Alpha-Mendeleev ridge complex underlie a significant proportion of the Arctic Ocean, but the geology of this undrilled and mostly ice-covered frontier is poorly known. New information is encoded in seismic wide-angle reflections and refractions recorded with expendable sonobuoys between 2007 and 2011. Velocity-depth samples within the sedimentary succession are extracted from published analyses for 142 of these records obtained at irregularly spaced stations across an area of 1.9E + 06 km 2 . The samples are modelled at regional, subregional and station-specific scales using an exponential function of inverse velocity versus depth with regionally representative parameters determined through numerical regression. With this approach, smooth, non-oscillatory velocity-depth profiles can be generated for any desired location in the study area, even where the measurement density is low. Practical application is demonstrated with a map of sedimentary thickness, derived from seismic reflection horizons interpreted in the time domain and depth converted using the velocity-depth profiles for each seismic trace. A thickness of 12-13 km is present beneath both the upper Mackenzie fan and the middle slope off of Alaska, but the sedimentary prism thins more gradually outboard of the latter region. Mapping of the observed-to-predicted velocities reveals coherent geospatial trends associated with five subregions: the Mackenzie fan; the continental slopes beyond the Mackenzie fan; the abyssal plain; the southwestern Canada Basin; and, the Alpha-Mendeleev magnetic domain. Comparison of the subregional velocity-depth models with published borehole data, and interpretation of the station-specific best-fitting model parameters, suggests that sandstone is not a predominant lithology in any of the five subregions. However, the bulk sand-to-shale ratio likely increases towards the Mackenzie fan, and the model for this subregion compares favourably with borehole data for Miocene turbidites in the eastern Gulf of Mexico. The station-specific results also indicate that Quaternary sediments coarsen towards the Beaufort-Mackenzie and Banks Island margins in a manner that is consistent with the variable history of Laurentide Ice Sheet advance documented for these margins. Lithological factors do not fully account for the elevated velocity-depth trends that are associated with the southwestern Canada Basin and the Alpha-Mendeleev magnetic domain. Accelerated porosity reduction due to elevated palaeo-heat flow is inferred for these regions, which may be related to the underlying crustal types or possibly volcanic

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Section: Regional Velocity-depth Modelmentioning

confidence: 72%

Section: Geological Synopsismentioning

confidence: 99%

Section: Associations With Geothermal Heat Flow and Crustal Typementioning

confidence: 99%

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Seismic velocities within the sedimentary succession of the Canada Basin and southern Alpha-Mendeleev Ridge, Arctic Ocean: evidence for accelerated porosity reduction?

Shimeld¹,

Li²,

Chian³

et al. 2015

Geophysical Journal International

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“…The structure of the Alpha-Mendeleev Rise is described in [Jokat, 2003;Bruvoll et al, 2010Bruvoll et al, , 2012Dove et al, 2010;Døssing et al, 2013;Hegewald, Jokat, 2013;Weigelt et al, 2014;Brumley, 2014;Nikishin et al, 2014]. In this paper, we will not discuss its structure as a separate topic.…”

Section: Geological Structure Of the Alpha-mendeleev Risementioning

confidence: 99%

“…1) [e.g., Laverov et al, 2013;Vernikovsky et al, 2013;Gaina et al, 2014;Pease et al, 2014;Nikishin et al, 2014;Petrov et al, 2016;Drachev, 2016]. Different versions of the stratigraphy of the ocean's sedimentary cover were presented in [Kim, Glezer, 2007;Backman et al, 2008;Bruvoll et al, 2010Bruvoll et al, , 2012Rekant, Gusev, 2012;Mosher et al, 2012;Døssing et al, 2013;Dobretsov et al, 2013;Weigelt et al, 2014;Jokat, Ickrath, 2015;Nikishin et al, 2014;Brumley, 2014;Rekant et al, 2015;Evangelatos, Mosher, 2016]. Large-scale seismic surveys were recently conducted on the shelves of the Laptev, East Siberian and Chukchi Seas, as well as in the deep-water part of the Arctic Ocean Rekant et al, 2015].…”

Section: Introductionmentioning

confidence: 99%

Rift systems of the Russian Eastern Arctic shelf and Arctic deep water basins: link between geological history and geodynamics

Nikishin¹,

Petrov²,

Малышев³

et al. 2017

Geodin. tektonofiz.

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Abstract:In our study, we have developed a new tectonic scheme of the Arctic Ocean, which is based mainly on seismic profiles obtained in the Arctic-2011, Arctic-2012 and Arctic-2014 Projects implemented in Russia. Having interpreted many seismic profiles, we propose a new seismic stratigraphy of the Arctic Ocean. Our main conclusions are drawn from the interpretation of the seismic profiles and the analysis of the regional geological data. The results of our study show that rift systems within the Laptev, the East Siberian and the Chukchi Seas were formed not earlier than Aptian. The geological structure of the Eurasian, Podvodnikov, Toll and Makarov Basins is described in this paper. Having synthesized all the available data on the study area, we propose the following model of the geological history of the Arctic Ocean: 1. The Canada Basin formed till the Aptian (probably, during Hauterivian-Barremian time). 2. During the Aptian-Albian, large-scale tectonic and magmatic events took place, including plume magmatism in the area of the De Long Islands, Mendeleev Ridge and other regions. Continental rifting started after the completion of the Verkhoyansk-Chukotka orogenу, and rifting occurred on the shelf of the Laptev, East Siberian, North Chukchi and South Chukchi basins, and the Chukchi Plateau; simultaneously, continental rifting started in the Podvodnikov and Toll basins. 3. Perhaps the Late Cretaceous rifting continued in the Podvodnikov and Toll basins. 4. At the end of the Late Cretaceous and Paleocene, the Makarov basin was formed by rifting, although local spreading of oceanic crust during its formation cannot be excluded. 5. The Eurasian Basin started to open in the Early Eocene. We, of course, accept that our model of the geological history of the Arctic Ocean, being preliminary and debatable, may need further refining. In this paper, we have shown a link between the continental rift systems on the shelf and the formation history of the Arctic Ocean. Аннотация: На основе российских сейсмических профилей, полученных в рамках проектов Арктика-2011, Арктика-2012 и Арктика-2014, составлена новая тектоническая схема Арктического океана. Приведены ре-зультаты интерпретации многих сейсмических профилей, представлена новая сейсмостратиграфия для Арк-тического океана. Основные выводы сделаны на основе интерпретации сейсмических профилей и на базе анализа региональных геологических данных. Показано, что рифтовые системы в пределах морей Лаптевых, Восточно-Сибирского и Чукотского были образованы не раньше аптского времени. Дано описание геологиче-ского строения бассейнов Евразийского, Подводников, Толля, Макарова и других. На основе синтеза всех дан-ных получена следующая модель истории Арктического океана. 1. Канадский бассейн был образован до апт-ского времени (вероятно, в готериве-барреме). 2. В апте-альбе были крупномасштабные тектонические и магматические события: плюмовый магматизм был в районе поднятия Де-Лонга, на хребте Менделеева и в других областях. Континентальный рифтинг произошел сразу после оконча...

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Arctic Deep Water Ferromanganese‐Oxide Deposits Reflect the Unique Characteristics of the Arctic Ocean

Hein

Konstantinova²,

Mikesell

et al. 2017

Geochem Geophys Geosyst

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Little is known about marine mineral deposits in the Arctic Ocean, an ocean dominated by continental shelf and basins semi‐closed to deep‐water circulation. Here, we present data for ferromanganese crusts and nodules collected from the Amerasia Arctic Ocean in 2008, 2009, and 2012 (HLY0805, HLY0905, and HLY1202). We determined mineral and chemical compositions of the crusts and nodules and the onset of their formation. Water column samples from the GEOTRACES program were analyzed for dissolved and particulate scandium concentrations, an element uniquely enriched in these deposits. The Arctic crusts and nodules are characterized by unique mineral and chemical compositions with atypically high growth rates, detrital contents, Fe/Mn ratios, and low Si/Al ratios, compared to deposits found elsewhere. High detritus reflects erosion of submarine outcrops and North America and Siberia cratons, transport by rivers and glaciers to the sea, and distribution by sea ice, brines, and currents. Uniquely high Fe/Mn ratios are attributed to expansive continental shelves, where diagenetic cycling releases Fe to bottom waters, and density flows transport shelf bottom water to the open Arctic Ocean. Low Mn contents reflect the lack of a mid‐water oxygen minimum zone that would act as a reservoir for dissolved Mn. The potential host phases and sources for elements with uniquely high contents are discussed with an emphasis on scandium. Scandium sorption onto Fe oxyhydroxides and Sc‐rich detritus account for atypically high scandium contents. The opening of Fram Strait in the Miocene and ventilation of the deep basins initiated Fe‐Mn crust growth ∼15 Myr ago.

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The nature of the acoustic basement on Mendeleev and northwestern Alpha ridges, Arctic Ocean

Cited by 59 publications

References 69 publications

Seismic velocities within the sedimentary succession of the Canada Basin and southern Alpha-Mendeleev Ridge, Arctic Ocean: evidence for accelerated porosity reduction?

Seismic velocities within the sedimentary succession of the Canada Basin and southern Alpha-Mendeleev Ridge, Arctic Ocean: evidence for accelerated porosity reduction?

Rift systems of the Russian Eastern Arctic shelf and Arctic deep water basins: link between geological history and geodynamics

Arctic Deep Water Ferromanganese‐Oxide Deposits Reflect the Unique Characteristics of the Arctic Ocean

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