AIRBORNE GEOPHYSICAL RECONNAISSANCE IN THE CANADIAN ARCTIC ARCHIPELAGO

Geophysics ◽  
1961 ◽  
Vol 26 (6) ◽  
pp. 727-737 ◽  
Author(s):  
A. F. Gregory ◽  
L. W. Morley ◽  
Margaret E. Bower
Keyword(s):  
Sedimentary Rocks ◽  
Canadian Arctic ◽  
Sedimentary Basins ◽  
Magnetic Anomalies ◽  
Canadian Arctic Archipelago ◽  
Structural Detail ◽  
Apparent Absence ◽  
Geophysical Surveys ◽  
Sverdrup Basin ◽  
Igneous Activity

Profiles of total magnetic intensity and gamma radioactivity were obtained along a series of widely‐spaced flight lines across the main tectonic regions of the Canadian Arctic Archipelago. The interpretation of these data and the calculated depths‐to‐basement substantiate the recognized regional structures, confirm general geological continuity between the islands, and provide some additional structural detail. Results of particular interest are the maximum depths‐to‐basement in the sedimentary basins (10,000 ft or greater), the interpretation of the structure of the Precambrian arches, the extent of nonbasement igneous activity, the apparent absence of disturbed ferromagnetic rocks on the Polar Continental Shelf except near the edge where a few deep basement‐type anomalies were observed, and the occurrence of anomalous radioactivity in certain sedimentary rocks on Bathurst Island. Remarkable magnetic anomalies, which in profile show a central minimum with marginal maxima, are characteristic of known gypsum domes in the Sverdrup Basin. It is concluded that reconnaissance geophysical surveys of comparable geological regions can provide much information concerning the structure and lithology of the area. In particular, this survey reveals geophysical contrasts of significance in the planning of future investigations in the archipelago and points out a number of interesting anomalies which require further study.

Middle Jurassic to Lower Cretaceous paleoclimate of Sverdrup Basin, Canadian Arctic Archipelago inferred from the palynostratigraphy

2013 ◽  
Vol 44 ◽  
pp. 240-255 ◽  
Author(s):  
Jennifer M. Galloway ◽  
Arthur R. Sweet ◽  
Graeme T. Swindles ◽  
Keith Dewing ◽  
Thomas Hadlari ◽  
...  
Keyword(s):  
Lower Cretaceous ◽  
Middle Jurassic ◽  
Canadian Arctic ◽  
Canadian Arctic Archipelago ◽  
Sverdrup Basin

Geothermal gradients and terrestrial heat flow along a south‐north profile in the Sverdrup Basin, Canadian Arctic Archipelago

Geophysics ◽  
1990 ◽  
Vol 55 (8) ◽  
pp. 1105-1107 ◽  
Author(s):  
F. W. Jones ◽  
J. A. Majorowicz ◽  
A. F. Embry ◽  
A. M. Jessop
Keyword(s):  
Fluid Flow ◽  
Heat Flow ◽  
Lower Cretaceous ◽  
Canadian Arctic ◽  
Thermal Anomaly ◽  
Temperature Gradients ◽  
Petroleum Exploration ◽  
Canadian Arctic Archipelago ◽  
Sverdrup Basin ◽  
Sill Intrusion

Data from eleven petroleum exploration wells along a south‐north profile in the Sverdrup Basin of the Canadian Arctic Islands indicate large variations in temperature gradients(18 ± 2 to 39 ± 2 mK/m) and heat‐flow values [Formula: see text]. High values occur near the axis of the basin and values decrease systematically toward the southern and northern flanks of the basin. The basin axis in this area is the zone of maximum crustal attenuation and Lower Cretaceous dike and sill intrusion, but any thermal anomaly associated with these events will have dissipated by now. The present heat‐flow pattern is likely the result of thermal refraction or fluid flow in the basin.

Paleozoic metamorphism across the boundary between the Clements Markham fold belt and the Pearya terrane in northern Ellesmere Island, Canadian Arctic Archipelago

1993 ◽  
Vol 30 (4) ◽  
pp. 867-880 ◽  
Author(s):  
Eva M. Klaper ◽  
Yoshihide Ohta
Keyword(s):  
Invariant Point ◽  
Sedimentary Rocks ◽  
Canadian Arctic ◽  
Boundary Region ◽  
Ellesmere Island ◽  
Canadian Arctic Archipelago ◽  
Fold Belt ◽  
Garnet Porphyroblasts ◽  
Single Episode ◽  
Differential Uplift

Microstructural and petrological data suggest that a single episode of syn- to post-tectonic metamorphism affected the boundary region between the Clements Markham fold belt and Pearya, a postulated Caledonian terrane, during a mid-Paleozoic orogenic event in northern Ellesmere Island. The sedimentary rocks of the Clements Markham fold belt pass from chlorite to biotite to garnet grade over a distance of about 10 km as the contact with the Mitchell Point belt gneisses of Pearya is approached from the south. Foliation development and chevron-style folding was followed by the growth of the index minerals chlorite, biotite, chloritoid, garnet, staurolite, and kyanite in semipelitic rocks in four metamorphic zones. Thermobarometry of garnet porphyroblasts indicates peak metamorphic conditions of about 600 °C and 600 MPa in the highest grade rocks. Chloritoid-involving phase relations define an invariant point at 540 °C and 500 MPa only 2 km away from the highest grade zone. It may be concluded from the calculated pressure and temperature differences over this short distance that the isogradic surfaces of the post-chevron-folding metamorphism are steeply oriented. Much of the observed metamorphic pattern can, therefore, be explained as the result of a significant post-chevron-folding differential uplift (overthrusting) of the hot Mitchell Point belt gneisses relative to the Clements Markham fold belt. This indicates that the Mitchell Point belt forms a thrust sheet which overlies the Clements Markham fold belt and that the accretion of Pearya predates the Late Silurian.

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