Geology of King Christian island, district of Franklin
Authors: Balkwill H R , Roy K J 
Published: February 2016

King Christian Island is in the central part of Sverdrup Basin, Canadian Arctic Archipelago. The island is low, has little relief, and is underlain by slightly folded and faulted Mesozoic sedimentary rocks. A rolling and scarped lowland in the central part of the
island has formed on shale and poorly indurated sandstone; this is flanked on the north and south by a lowland plain developed on soft recessive shale. Rocks exposed on King Christian Island consist of a conformable succession of Mesozoic terrigenous elastic strata, about 1875 m (4175 ft.) thick.
Thick sequences of nonmarine and marine sandstone alternate with marine siltstone and shale. In ascending order, the outcrop succession is composed of: (l) the upper 180 m (600 ft.) of the Deer Bay Formation (Upper Jurassic(?) and Lower Cretaceous), which consists of dark grey, silty, marine shale
with very thin sandstone beds and lenses near the top; (2) the Isachsen Formation (Lower Cretaceous), which is about 790 m (2600 ft.) thick and consists of fining-upward, cyclic repetitions of fluvially deposited sandstone, siltstone and shale with very minor amounts of coal; (3) marine, silty shale
of the Christopher Formation (Lower Cretaceous), which may be separated informally into a thick lower member (365 m (1200 ft.)), that is greenish grey and contains large, buff mudstone nodules, abundant silt, and an interval of glauconitic sandstone at the top, and an upper member of dark grey
shale, about 320 m (l 050 ft.) thick, containing small redbrown concretions; and (If) the Hassel Formation (Lower and (?)Upper Cretaceous), consisting of fining-upward, fluvially deposited, cyclic repetitions of sandstone, siltstone and shale with minor amounts of coal. The uppermost beds of the
Hassel Formation and succeeding Mesozoic formations have been removed by erosion. Five wells have been drilled on the island, including one relief well. Natural gas was reported in all of the wells. Subsurface formations penetrated in the 11 020 -foot (3360 m) deep Panarctic Tenneco et al. King
Christian N-06 well are as follows, from the top downward: the lower part of the Deer Bay Formation (Upper Jurassic and ?Lower Cretaceous); silty, calcareous shale, assigned to the Ringnes Formation (Upper Jurassic); the Savik Formation (Middle and Lower Jurassic), consisting of the Upper Shale
Member, a thin interval of glauconitic sandstone and siltstone assigned to the Jaeger Member, and the Lower Shale Member; undivided sandstone of the Borden Island Formation and the Upper Member of the Heiberg Formation (Lower Jurassic and Upper Triassic); intercalated sandstone and shale of the
Heiberg Formation Lower Member (Upper Triassic); and the deepest rocks penetrated, which comprise silty shale of the Blaa Mountain Formation (Middle and Upper Triassic) and, possibly, the upper part of the Blind Fiord Formation (Lower Triassic). The reservoir interval for natural gas is in the upper
part of the Borden Island/Upper Heiberg interval. The geological structure is simple: a broad, ovate, northwestward-trending structural depression is flanked by a closed anticline on the eastern coast, and by eastward-dipping beds along the western coast, which may be part of a similar anticline.
Regional evidence indicates that the latest phase of tectonism and uplift probably was in Late Cretaceous and early Tertiary. Development of deep fold roots as a result of mobilization of deeply buried evaporites may have preceded this. King Christian Island is the site of major discoveries of
natural gas, which is trapped structurally in ovate anticlines. Possibilities of significant coal or sedimentary uranium deposits are considered poor.