A reassessment of Mesozoic-Cenozoic seabed samples of bedrock from the western Davis Strait and eastern Baffin Island margin, offshore Nunavut: new insights into their lithology, age, and paleoenvironment of deposition

Fine- to medium-grained, phyric and aphyric basalt samples from ODP Leg 105, site 647A, in the Labrador Sea show little evidence of alteration. Chemically, these rocks are low-potassium (0.01–0.09 wt.% K2O), olivine- to quartz-normative tholeiites that compare closely with the very depleted terrestrial Paleocene volcanic rocks in the Davis Strait region of Baffin Island and West Greenland. However, differences exist in the Sr–Nd isotope systematics of the two suites; the Labrador Sea samples have ε Nd values (+9.3) indicative of a more depleted source, and are higher in 87Sr/86Sr (0.7040), relative to the Davis Strait basalts (ε Nd +2.54 to +8.97; mean 87Sr/86Sr 0.7034). The higher 87Sr/86Sr in the Labrador Sea samples may reflect seawater exchange despite no petrographic evidence for significant alteration. The Labrador Sea and early Davis Strait basalts may have been derived from a similar depleted mantle source composition; however, the later Davis Strait magmas were generated from a different mantle. None of the Baffin Island, West Greenland, or Labrador Sea samples show unequivocal geochemical evidence for contamination with continental crust.

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Tertiary basalts of western Davis Strait: bedrock core samples and geophysical data

Canadian Journal of Earth Sciences ◽

10.1139/e78-083 ◽

1978 ◽

Vol 15 (5) ◽

pp. 773-780 ◽

Cited By ~ 9

Author(s):

B. MacLean ◽

R. K. H. Falconer ◽

D. B. Clarke

Keyword(s):

Magnetic Anomaly ◽

Seismic Reflection ◽

Volcanic Rocks ◽

Geophysical Data ◽

Baffin Island ◽

Main Area ◽

Fine Grained ◽

Core Samples ◽

Davis Strait ◽

Island Shelf

Short bedrock cores of basalt were recovered at two localities on the Baffin Island shelf, 33 and 89 km southeast of Cape Dyer. The volcanic rocks underlying these sites have a surface extent of some 8000 km2 as outlined by seismic reflection and magnetic anomaly profiles. Similar rocks are inferred to occur at two smaller offshore areas south of the main area. The offshore occurrences are both more continuous and much larger than the onshore basalt areas of eastern Baffin Island.The core samples appear to have been cut from single flows consisting of fine-grained microporphyritic basalts with olivine as the principal phenocryst phase. Although having distinct differences from one another in terms of texture and degree of alteration, the samples from the three drill stations bear similarities to the Baffin Island basalts that suggest a close petrogenetic relationship may exist between the onshore and offshore basalts. However, in contrast to the subaqueously erupted volcanic breccias of onshore Baffin Island and West Greenland the offshore samples contain little evidence of glass, suggesting the possibility that the latter may have been erupted in a subaerial environment.

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Multiyear Volume, Liquid Freshwater, and Sea Ice Transports through Davis Strait, 2004–10*

Journal of Physical Oceanography ◽

10.1175/jpo-d-13-0177.1 ◽

2014 ◽

Vol 44 (4) ◽

pp. 1244-1266 ◽

Cited By ~ 96

Author(s):

B. Curry ◽

C. M. Lee ◽

B. Petrie ◽

R. E. Moritz ◽

R. Kwok

Keyword(s):

Sea Ice ◽

North Atlantic ◽

Volume Transport ◽

The Arctic ◽

Baffin Island ◽

Transport Time ◽

Freshwater Transport ◽

Davis Strait ◽

Standard Deviations ◽

Thickness Measurements

Abstract Davis Strait is a primary gateway for freshwater exchange between the Arctic and North Atlantic Oceans including freshwater contributions from west Greenland and Canadian Arctic Archipelago glacial melt. Data from six years (2004–10) of continuous measurements collected by a full-strait moored array and concurrent high-resolution Seaglider surveys are used to estimate volume and liquid freshwater transports through Davis Strait, with respective annual averages of −1.6 ± 0.5 Sverdrups (Sv; 1 Sv ≡ 106 m3 s−1) and −93 ± 6 mSv (negative sign indicates southward transport). Sea ice export contributes an additional −10 ± 1 mSv of freshwater transport, estimated using satellite ice area transport and moored upward-looking sonar ice thickness measurements. Interannual and annual variability of the net transports are large, with average annual volume and liquid freshwater transport standard deviations of 0.7 Sv and 17 mSv and with interannual standard deviations of 0.3 Sv and 15 mSv. Moreover, there are no clear trends in the net transports over the 6-yr period. However, salinity in the upper 250 m between Baffin Island and midstrait decreases starting in September 2009 and remains below average through August 2010, but appears to return to normal by the end of 2010. This freshening event, likely caused by changes in arctic freshwater storage, is not apparent in the liquid freshwater transport time series due to a reduction in southward volume transport in 2009–10. Reanalysis of Davis Strait mooring data from the period 1987–90, compared to the 2004–10 measurements, reveals less arctic outflow and warmer, more saline North Atlantic inflow during the most recent period.

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Measurements of Benthic Macroinvertebrate Standing Crop from the Canadian Continental Shelf and Slope of Southern Davis Strait and Ungava Bay

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f83-087 ◽

1983 ◽

Vol 40 (5) ◽

pp. 652-657 ◽

Cited By ~ 6

Author(s):

Patrick L. Stewart

Keyword(s):

Continental Shelf ◽

North American ◽

Standing Crop ◽

Benthic Macroinvertebrate ◽

Baffin Island ◽

Medium Sand ◽

Grand Banks ◽

Sediment Content ◽

Davis Strait

Benthic macroinvertebrate standing crop at 14 stations on the Canadian continental shelf, southeast of Baffin Island, ranged from 19.8 to 479.9 g/m2 and was about the same size for given depths, as reported for the Grand Banks of Newfoundland, and higher than reported in more southerly portions of the eastern North American continental shelf. Standing crop was correlated negatively with depth and sediment content of both fine and medium sand.

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Volume, Freshwater, and Heat Fluxes through Davis Strait, 2004–05*

Journal of Physical Oceanography ◽

10.1175/2010jpo4536.1 ◽

2011 ◽

Vol 41 (3) ◽

pp. 429-436 ◽

Cited By ~ 87

Author(s):

B. Curry ◽

C. M. Lee ◽

B. Petrie

Keyword(s):

Heat Fluxes ◽

First Year ◽

Baffin Island ◽

Fram Strait ◽

The West ◽

Baffin Bay ◽

Freshwater Fluxes ◽

Davis Strait ◽

Island Shelf ◽

Southward Transport

Abstract Davis Strait volume [−2.3 ± 0.7 Sv (1 Sv ≡ 106 m3 s−1); negative sign indicates southward transport], freshwater (−116 ± 41 mSv), and heat (20 ± 9 TW) fluxes estimated from objectively mapped 2004–05 moored array data do not differ significantly from values based on a 1987–90 array but are distributed differently across the strait. The 2004–05 array provided the first year-long measurements in the upper 100 m and over the shelves. The upper 100 m accounts for 39% (−0.9 Sv) of the net volume and 59% (−69 mSv) of the net freshwater fluxes. Shelf contributions are small: 0.4 Sv (volume), 15 mSv (freshwater), and 3 TW (heat) from the West Greenland shelf and −0.1 Sv, −7 mSv, and 1 TW from the Baffin Island shelf. Contemporaneous measurements of the Baffin Bay inflows and outflows indicate that volume and freshwater budgets balance to within 26% and 4%, respectively, of the net Davis Strait outflow. Davis Strait volume and freshwater fluxes nearly equal those from Fram Strait, indicating that both are significant Arctic freshwater pathways.

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Early Tertiary, low-potassium tholeiites from exploration wells on the West Greenland shelf

Rapport Grønlands Geologiske Undersøgelse ◽

10.34194/rapggu.v136.8008 ◽

1987 ◽

Vol 136 ◽

pp. 1-25

Author(s):

N Hald ◽

J.G Larsen

Keyword(s):

Baffin Island ◽

Quaternary Sediments ◽

The South ◽

The West ◽

Baffin Bay ◽

West Greenland ◽

Early Tertiary ◽

Davis Strait ◽

Low Potassium

Data on the Tertiary basalts in the Davis Strait region are reported from two exploration wells drilled by Arco and Mobil on the West Greenland shelf. Hellefisk 1 (67°53 'N, 56°44'W), situated only 60 km east of the mid-line in Davis Strait, penetrated the upper 690 m of a subaeriallava sequence continuous with the onshore volcanics of Disko and situated beneath 2.3 km of Paleocene to Quaternary sediments. The lavas are feldspar microporphyritic tholeiites and mostly unmetamorphosed despite the presence of laumontite and prehnite in the vesicular top zones. Nukik 2 (65°38'N, 54°46'W) penetrated 150 m of hyaloclastites and tholeiitic olivine dolerite sheets, presumably sills, some 200 km further to the south. These vo1canics are also deeply buried and are of unknown extension. The drilled rocks, except for the much altered hyaloclastites in the Nukik 2 well, have low contents of Ti02 (0.99-2.03%), K2O (0.09-0.18%) and P2O5 (0.08-0.21%), La/Sm ratios less than one and 87Sr/86Sr ratios of 0.7032 to 0.7044. Chemically they are related to the MORB-like picrites of Baffin Island rather than the less depleted tholeiites of West Greenland. In both areas the MORB affinity may be related to eruptions through a strongly attenuated lithosphere associated with the opening of Baffin Bay and Davis Strait.

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Depleted and ultradepleted basalt and picrite in the Davis Strait: Paleocene volcanism associated with a transform continental margin

Geological Magazine ◽

10.1017/s0016756820000175 ◽

2020 ◽

Vol 157 (12) ◽

pp. 1983-2003 ◽

Cited By ~ 1

Author(s):

Lotte Melchior Larsen ◽

Marie-Claude Williamson

Keyword(s):

Volcanic Rocks ◽

Spinel Peridotite ◽

Baffin Island ◽

Nd Isotopes ◽

Enriched Mantle ◽

Spreading Ridges ◽

Magmatic Underplating ◽

Davis Strait ◽

Melting Regime ◽

Transform Zone

AbstractVolcanic rocks from the Davis Strait were studied to elucidate the tectonomagmatic processes during rifting and the start of seafloor spreading, and the formation of the Ungava transform zone between Canada and Greenland. The rocks are from the wells Hekja O-71, Gjoa G-37, Nukik-2 and Hellefisk-1, and from dredges on the northern Davis Strait High. Ages range from Danian to Thanetian (dinocyst palynozones P2 to P5, 62.5–57.2 Ma). The rocks are predominantly basaltic, but include picrites on the Davis Strait High. Calculated mantle potential temperatures for the Davis Strait High are c. 1500°C, suggesting the volume of magma generated was large; this is consistent with geophysical evidence for magmatic underplating in the region. The rare earth element patterns indicate residual mantle lithologies of spinel peridotite and, together with Sr–Nd isotopes, indicate melting beneath regionally extensive, depleted asthenosphere beneath a lithosphere of thickness similar to, or thinner than, beneath Baffin Island and distinctly thinner than beneath West Greenland. Some sites include basalts with more enriched compositions. Depleted and enriched basalts in the Hellefisk well show contemporaneous melting of depleted and enriched mantle components in the asthenosphere. The Hekja and Davis Strait High basalts and picrites have unique, ultradepleted compositions with (La/Sm)N < 0.5, (Tb/Lu)N < 1 and Nb/Zr = 0.013–0.027. We interpret these compositions as a product of the melting regime within the Ungava transform zone, where the melting column would be steep-sided in cross-section and not triangular as expected at normal spreading ridges. Magmatism along the transform stopped when the tectonic regime changed from transtension to transpression during earliest Eocene time.

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The road to Cathay and the Hudson's Bay Company

Polar Record ◽

10.1017/s003224740006143x ◽

1971 ◽

Vol 15 (97) ◽

pp. 453-462

Author(s):

E. E. Rich

Keyword(s):

Baffin Island ◽

Hudson's Bay Company ◽

North West ◽

The Road ◽

The North ◽

Davis Strait ◽

Cumberland Sound ◽

Royal Charter ◽

Hudson’S Bay Company

There had been no English expedition to search for the North-west Passage for 40 years before the Hudson's Bay Company received its royal charter on 2 May 1670. Early enthusiasm, generated largely by Sir Humphrey Gilbert and the “Colleagues of the Fellowship for the discovery of the North-West Passage”, had been put to the test by the maritime skills of Frobisher and of Davis. But, although Frobisher had returned from his first voyage, in October 1576, convinced that he had found the passage and had “passed above fiftie leagues therein”, he had in fact crossed westwards from the coast of Greenland to enter Frobisher Bay on Baffin Island (Collinson, 1867, p 72); experience was to prove that no passage lay that way. Davis, too, came back from his first voyage convinced that, in 1585, he had in all likelihood been in “the place and passage by us laboured for” (Hakluyt, 1927, Vol 5, p 333). He had then entered Cumberland Sound, also on Baffin Island. Davis's second voyage brought him to Hudson Strait and convinced him (as Frobisher in turn had thought) that the great “overfall” of the water there betokened a vast sea to the westwards. He was sure that the passage could now be found without further cost. But Davis's third voyage, in 1587, took him, first, north through Davis Strait up the coast of Baffin Island and then, crossing eastwards, up the coast of Greenland as high as lat 73 °N, where he still found the sea open although the wind was contrary. Returning down the coast, he was again impressed by the “great ruttes” of the “overfall” in Hudson Strait and he concluded that, of the four possible openings for the passage, this one was the most likely. The others were to be found due north up Davis Strait, which he thought might be no more than a great gulf, or through Frobisher Bay or through Cumberland Sound, in both of which he had been held by ice (Hakluyt, 1927, Vol 5, p 281–336.)

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Blood protozoans of fish from the Davis Strait in the northwestern Atlantic Ocean

Canadian Journal of Zoology ◽

10.1139/z91-064 ◽

1991 ◽

Vol 69 (2) ◽

pp. 410-413 ◽

Cited By ~ 8

Author(s):

R. A. Khan ◽

E. M. Lee ◽

W. S. Whitty

Keyword(s):

Atlantic Ocean ◽

Fish Species ◽

The Other ◽

Baffin Island ◽

Grand Banks ◽

Northern Latitudes ◽

Davis Strait ◽

Reinhardtius Hippoglossoides ◽

Raja Radiata ◽

Hippoglossoides Platessoides

A study was carried out to determine the occurrence and prevalence of blood protozoans in benthic marine fish from the Davis Strait, an area between Baffin Island and Greenland (61–70°N, 53–63°W) in the northwestern Atlantic Ocean. Parasites were seen in all 17 species offish examined; piroplasms were most prevalent (78% of 413), infecting all fish species. Prevalences of infection were substantially lower for trypanosomes (23%) and haemogregarines (4%), both of which infected only 10 and 6 of the fish species, respectively. Prevalences were greater in 5 of the fish species examined, Reinhardtius hippoglossoides, Hippoglossoides platessoides, Lycodes lavalaei, Macrourus berglax, and Raja radiata, than in the other 12 species. Though the prevalence of trypanosomes decreased considerably in the most northerly of three areas, no differences were apparent for piroplasms. Prevalences noted in this paper are comparable to those observed in fish taken off the coast of Labrador but considerably greater than those of the Grand Banks or in areas south of latitude 50°N. Based on occurrence and prevalence, it is likely that fish haematozoans and their leech vectors originated in the northern latitudes and radiated southwards.

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