scholarly journals Geology of the Canadian Arctic Archipelago, Northwest Territories and North Greenland

1991 ◽  
Author(s):  
A V Okulitch
Keyword(s):  
Northwest Territories ◽  
Canadian Arctic ◽  
Canadian Arctic Archipelago ◽  
North Greenland

scholarly journals Silurian ostracoderms from Washington Land (North Greenland), with comments on cyathaspid structure, systematics and phyletic position

1986 ◽  
Vol 132 ◽  
pp. 89-123
Author(s):  
S.E Bendix-Almgreen
Keyword(s):  
Canadian Arctic ◽  
Stability Control ◽  
Canadian Arctic Archipelago ◽  
Marine Deposits ◽  
Type Section ◽  
Cape Phillips Formation ◽  
North Greenland

The few detached dermal elements recorded here document a new ostracoderm fauna comprising undeterminable species of one anaspid, two cyathaspids and a heterostracan which might have its closest relatives among the pteraspids. This fauna is derived from marine deposits of ultimate Wenlock or possibly Early Ludlow age at the top of the Lafayette Bugt Formation in its type section, in Washington Land, western North Greenland. It is probably equivalent to one of the undescribed faunas known from the Monograptus testis - M. nilssoni sequence of the Cape Phillips Formation in the Canadian Arctic Archipelago. Comparative material from Norway and Spitsbergen is considered in this study which prompted general comments on cyathaspid squamation, vestigial fin structure, cyathaspid systematics, their phyletic position relative to the pteraspids, system of stability control in swimming, their habitats and diets.

Reassessment of Ischnacanthus? scheii Spjeldnaes (Acanthodii, Ischnacanthiformes) from the latest Silurian or earliest Devonian of Ellesmere Island, arctic Canada

2013 ◽  
Vol 50 (9) ◽  
pp. 945-954 ◽  
Author(s):  
Carole J. Burrow
Keyword(s):  
Canadian Arctic ◽  
Biological Species ◽  
Ellesmere Island ◽  
Canadian Arctic Archipelago ◽  
Devon Island ◽  
Thin Sectioning ◽  
Bone Fragments ◽  
Cornwallis Island ◽  
North Greenland ◽  
Fin Spines

Articulated specimens of jawed fishes, and assemblages of disarticulated elements that can be assigned to a single biological species, are extremely rare from pre-Devonian deposits. The acanthodian species Ischnacanthus? scheii Spjeldnaes is based on a monospecific assemblage, comprising fin spines, dentigerous jaw bone fragments and scales, from the ?Siluro-Devonian boundary beds of the Devon Island Formation in central west Ellesmere Island, Canadian Arctic Archipelago, Nunavut. A new examination of the type material, in particular by scanning electron microscopy and thin sectioning of scales, shows that the species is a porosiform poracanthodid that is now assigned to Radioporacanthodes scheii comb. nov. Scales of the same species are also recognized from the upper Pridoli of Cornwallis Island and the ?Pridoli or Lochkovian of north Greenland.

Silurian (Wenlockian) trilobites from Baillie-Hamilton Island, Canadian Arctic Archipelago

1977 ◽  
Vol 14 (2) ◽  
pp. 285-317 ◽  
Author(s):  
D. G. Perry ◽  
B. D. E. Chatterton
Keyword(s):  
New Species ◽  
Northwest Territories ◽  
New Taxa ◽  
Canadian Arctic ◽  
Canadian Arctic Archipelago ◽  
Cape Phillips Formation ◽  
Mackenzie Mountains

Wenlockian trilobites representing at least 15 genera are reported from carbonate strata within the Cape Phillips Formation, Baillie-Hamilton Island. The collections are stratigraphically bounded by the graptolite Zones of Cyrtograptus murchisoni and Monograptus testis. The fauna is generically dominated by lichids, odontopleurids, and cheirurids. Scutelluids, phacopids, dalmanitids, and harpids are notable for their absence. At the familial level the fauna corresponds to one recently discovered from similar age beds of the Mackenzie Mountains, Northwest Territories. The limited quantity and fragmental nature of much of the silicified fauna precludes erection of many new taxa, although four new species described are: Sphaerexochus dimorphus, Dicranogmus skinneri, Hemiarges rohri, and Hemiarges mikulici. Dimorphic pygidia are interpreted as probable sexual dimorphs in Sphaerexochus dimorphus n. sp.

scholarly journals Pleistocene organic matter modified by the Hiawatha impact, northwest Greenland

Geology ◽  
2020 ◽  
Vol 48 (9) ◽  
pp. 867-871 ◽  
Author(s):  
Adam A. Garde ◽  
Anne Sofie Søndergaard ◽  
Carsten Guvad ◽  
Jette Dahl-Møller ◽  
Gernot Nehrke ◽  
...  
Keyword(s):  
Organic Matter ◽  
Impact Crater ◽  
Canadian Arctic ◽  
Early Pleistocene ◽  
Sand Sample ◽  
Canadian Arctic Archipelago ◽  
Outwash Plain ◽  
The Impact ◽  
Firm Evidence ◽  
North Greenland

Abstract The 31-km-wide Hiawatha impact crater was recently discovered under the ice sheet in northwest Greenland, but its age remains uncertain. Here we investigate solid organic matter found at the tip of the Hiawatha Glacier to determine its thermal degradation, provenance, and age, and hence a maximum age of the impact. Impactite grains of microbrecchia and shock-melted glass in glaciofluvial sand contain abundant dispersed carbon, and gravel-sized charcoal particles are common on the outwash plain in front of the crater. The organic matter is depleted in the thermally sensitive, labile bio-macromolecule proto-hydrocarbons. Pebble-sized lumps of lignite collected close to the sand sample consist largely of fragments of conifers such as Pinus or Picea, with greatly expanded cork cells and desiccation cracks which suggest rapid, heat-induced expansion and contraction. Pinus and Picea are today extinct from North Greenland but are known from late Pliocene deposits in the Canadian Arctic Archipelago and early Pleistocene deposits at Kap København in eastern North Greenland. The thermally degraded organic material yields a maximum age for the impact, providing the first firm evidence that the Hiawatha crater is the youngest known large impact structure on Earth.

scholarly journals Jurassic - Cretaceous boundary strata of the extreme Arctic (Peary Land,.North Greenland)

1981 ◽  
Vol 30 ◽  
pp. 11-42
Author(s):  
E. Håkansson ◽  
T. Birkelund ◽  
S. Piasecki ◽  
V. A. Zakharov
Keyword(s):  
North America ◽  
Early Cretaceous ◽  
Late Jurassic ◽  
Canadian Arctic ◽  
Russian Platform ◽  
Close Similarity ◽  
Canadian Arctic Archipelago ◽  
East Greenland ◽  
Sverdrup Basin ◽  
North Greenland

A fossiliferous Late Jurassic-Early Cretaceous sequence is described from the Wandel Sea Basin, eastern North Greenland. The area was transgressed in the Middle Oxfordian and a gradually shallowing marine regime prevailed until Early Valanginian time, when conditions became !ironic. Stratigraphic data based on dinoflagellate cysts, ammonites and Buchia species indicate the presence of strata of Middle and Late Oxfordian, Kimmeridgian, Middle and Late Volgian, Early and Late Ryazanian, and Early Valanginian ages. Both the dinoflagellate assemblages and the mollusc faunas show close similarity to assemblages from the Sverdrup Basin of the Canadian Arctic Archipelago, Svalbard and northern USSR. They are also linked to more southern Boreal and Sub-Boreal areas in East Greenland, England, the Russian Platform and to some extent, North America. An integrated dinoflagellate-ammonite-Buchia stratigra­phy shows that the Early Cretaceous dinoflagellate assemblage appeared later in the Wandel Sea Basin than further south. It is also seen that a discrete "Jurassic" dinoflagellate assemblage existed for some time in the Early Cretaceous unaffected by the general tum-over at the Jurassic-Cretaceous boundary. Dinoflagellate, ammonite and Buchia assemblages are briefly discussed and selected species figured.

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