Giant dyke swarms and the reconstruction of the Canadian Arctic islands, Greenland, Svalbard and Franz Josef Land

Buchan, Kenneth L.; Ernst, Richard E.

doi:10.1201/noe0415398992.ch2

Cited by 56 publications

(64 citation statements)

References 39 publications

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“…The dominance of dykes in the basement and sills in overlying Mesozoic formations indicate a extensional tectonic regime in Svalbard. This is consistent with the presence of a large radiating dyke swarm recognized in the Canadian Arctic (Buchan & Ernst 2006) and in Franz Josef Land (Dibner 1998), which was later divided by plate tectonic processes related to the opening of the North Atlantic Ocean. The depth of emplacement of sill intrusions in western Spitsbergen has been estimated at 1Á2 km (Maher 2001).…”

Section: Introductionsupporting

confidence: 67%

“…Their composition is similar to the Svalbard dolerites and geochemical parameters indicate their connection to initial rifting related to the opening of the Canada Basin (Bailey & Rasmussen 1997). Most of the rocks occur as dykes and sills (Buchan & Ernst 2006), although lavas and thick pyroclastic deposits are also known (Embry & Osadetz 1988). Some parts of these volcanics, for example, those occurring at the Hansen Point in Ellesmere Island (Estrada & Henjes-Kunst 2004), have bimodal and alkaline characteristics that unequivocally show their connection with the development of a continental rift system.…”

Section: Discussionmentioning

confidence: 91%

“…The effects of excess and/or inherited argon may also explain the significantly older age of this dolerite sample. Buchan & Ernst (2006) and references therein. The compilation uses data from Tarakhovskiy et al (1982), Campsie et al (1988), Estrada et al (2006), Kontak et al (2001) and Silantyev et al (2004).…”

Section: Discussionmentioning

confidence: 99%

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Dolerites of Svalbard, north-west Barents Sea Shelf: age, tectonic setting and significance for geotectonic interpretation of the High-Arctic Large Igneous Province

et al. 2011

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The dolerites of Svalbard are mineralogically and geochemically homogeneous with geochemical features typical of continental within-plate tholeiites. Their geochemistry is similar to tholeiites belonging to a bimodal suite defined as the High-Arctic Large Igneous Province (HALIP). K–Ar dating of numerous dolerites sampled from many locations across Svalbard define a narrow time span of this magmatism from 125.5±3.6 to 78.3±2.6 Mya. Discrete peaks of intensive activity occurred at 115.3, 100.8, 91.3 and 78.5 Mya corresponding to (1) breakup of the continental crust and formation of an initial rift as a result of mantle plume activity, located in the southern part of the Alpha Ridge; (2) magmatic activity related to spreading along the Alpha Ridge that led to the development of the initial oceanic crust and (3) continuation of spreading along the Alpha Ridge and termination of magmatic activity related to HALIP (last two peaks at 91.3 and 78.5 Mya)

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Section: Introductionsupporting

confidence: 67%

Section: Discussionmentioning

confidence: 91%

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Dolerites of Svalbard, north-west Barents Sea Shelf: age, tectonic setting and significance for geotectonic interpretation of the High-Arctic Large Igneous Province

et al. 2011

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“…Uncertainty is particularly high northward where the basin is obscured by the Alpha and Mendeleev ridges, which form an widespread (>1 million km 2 ), intensely magnetized, submarine magmatic complex extending along an arcuate trend for a distance of 1700 km between the Canadian Arctic and Siberian margins. The Alpha-Mendeleev ridge complex is generally considered to be part of a broader array of onshore-offshore Cretaceous volcanic rocks, dikes, and sills that are collectively referred to as the High Arctic Large Igneous Province (Tarduno 1998;Maher 2001;Drachev & Saunders 2003;Villeneuve & Williamson 2003;Buchan & Ernst 2006). The complex is also associated with the F1 magnetic domain of Saltus et al (2011;indicated on Fig.…”

Section: Geological Synopsismentioning

confidence: 99%

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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“…More information about the age and duration of the magmatism can be provided by the better accessible Cretaceous igneous rocks from coastal areas around the Arctic Ocean, which together with the submarine Alpha-Mendeleev Ridge are interpreted to be part of the High Arctic Large Igneous Province (HALIP; Tarduno et al, 1998;Maher, 2001;Drachev & Saunders, 2006). The HALIP includes continental flood basalts, mafic dykes and sills emplaced at the Barents Shelf region, De Long Islands, North Greenland, and the Canadian Queen Elizabeth Islands between c. 130 and 80 Ma (recently summarised by Buchan & Ernst, 2006;Nejbert et al, 2011;Tegner et al, 2011;Senger et al, 2014;Polteau et al, 2016;Thórarinsson et al, 2015). Late Cretaceous to Palaeogene, alkaline, mafic to felsic suites are known in North Greenland and in the Canadian Arctic (e.g., Dawes & Soper, 1970;Batten et al, 1981, Brown et al, 1987Embry & Osadetz, 1988;Estrada et al, 2010).…”

Section: Geological Overview Of the Northeast Canadian Arcticmentioning

confidence: 99%

Multistage Cretaceous magmatism in the northern coastal region of Ellesmere Island and its relation to the formation of Alpha Ridge – evidence from aeromagnetic, geochemical and geochronological data

Estrada¹,

Damaske²,

Henjes‐Kunst³

et al. 2016

NJG

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The poorly studied Alpha-Mendeleev Ridge of the Amerasia Basin of the Arctic Ocean is covered by a large magnetic high and interpreted to be part of the Cretaceous High Arctic Large Igneous Province (HALIP). At the north coast of Ellesmere Island, in the Yelverton Bay area, this characteristic magnetic high overlaps the shelf and the coastal area. Results of aeromagnetic surveys, geological fieldwork, geochronological, geochemical and Sr-Nd isotope analysis were combined to study the tectonic history of this part of the Canadian Polar margin. The basement, consisting of metamorphic rocks of the Pearya Terrane, was strongly affected by HALIP-related magmatism that is responsible for characteristic positive magnetic anomaly patterns. A broad magnetic high that can be traced to the Alpha Ridge covers the shelf and coastal areas of Yelverton Bay. It is caused by a voluminous intrusion into the continental crust at a depth of ca. 6-15 km. A chain of small positive magnetic anomalies crosses Wootton Peninsula from SW to NE and then curves into a NNE-SSW trend. It follows the coastline onshore and offshore and superimposes the southern and eastern margins of the broad magnetic high. On land, the anomaly chain covers fault-bounded outcrops of the Wootton Intrusive Complex (WIC) and the Hansen Point Volcanic Complex (HPVC), indicating that the entire anomaly chain is associated with a volcanogenic sequence. Rhyodacite that forms large parts of the HPVC east and west of Yelverton Bay extruded between c. 104 and 97 Ma (LA-ICP-MS U-Pb zircon ages). It originates from a tholeiitc suite and is probably genetically related to the deep intrusion. The HPVC together with the rhyodacite has an age range of c. 104-74 Ma and includes the mildly alkaline WIC (93-92 Ma). The northern coast of Ellesmere Island shows some characteristic features of a magma-rich rifted margin indicating an extensional evolution parallel to the North American margin between the openings of the Canada Basin and the Eurasian Basin.

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Giant dyke swarms and the reconstruction of the Canadian Arctic islands, Greenland, Svalbard and Franz Josef Land

Cited by 56 publications

References 39 publications

Dolerites of Svalbard, north-west Barents Sea Shelf: age, tectonic setting and significance for geotectonic interpretation of the High-Arctic Large Igneous Province

Dolerites of Svalbard, north-west Barents Sea Shelf: age, tectonic setting and significance for geotectonic interpretation of the High-Arctic Large Igneous Province

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

Multistage Cretaceous magmatism in the northern coastal region of Ellesmere Island and its relation to the formation of Alpha Ridge – evidence from aeromagnetic, geochemical and geochronological data

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