Massive ice of the Tuktoyaktuk area, western Arctic coast, Canada

Abstract

The extensive coastal exposure of massive underground ice at Peninsula Point, southwest of Tuktoyaktuk, Northwest Territories, is believed to be intrasedimental ice. The ice grew beneath a frozen diamicton during the downward aggradation of permafrost. The water source was probably glacier meltwater, with low negative δ18O values, that flowed, under a substantial pressure, through permeable unfrozen sands. Evidence for a high water pressure is shown by ice dikes, which extend upward from the massive ice into the superincumbent diamicton. The diamicton was frozen when the dike water was injected, as proven by the chill contacts and petrofabrics. The diamicton – massive ice contact is a conformable contact with features characteristic of downward freezing. The continuity of δ18O and δD profiles from the top of the massive ice downward to a depth of 10 m into the underlying frozen sand demonstrates a common water source for the massive ice and interstitial ice in the underlying sand. A similar continuity of δ18O profiles has been determined from three drill holes at another site 15 km northeast of Tuktoyaktuk, Northwest Territories. The ages of both the diamicton and massive ice at the Peninsula Point site are uncertain, because of unexplained differences in published radiocarbon dates.

The chronostratigraphy of Late Pleistocene glacial and periglacial aeolian activity in the Tuktoyaktuk Coastlands, NWT, Canada

“…The age of the Toker Point Stade has been variously assigned to the Early Wisconsinan (>35 ka; Rampton, 1988), to sometime between 33.7 and . 20 14 C ka BP (Dallimore 1 1997) and to as late as 1 17 -14 ka (Mackay and Dallimore, 1992) or shortly before . 14 ka (Murton 1 1997).…”

Thermally induced movements in ice-wedge polygons, western arctic coast: a long-term study

“…At the "Involuted Hill Site" about 15 km east of Tuktoyaktuk (Fig. 1), about 3 to 10 m of diamicton overlies 10 to 30 m of massive ice which is underlain by sands (Mackay, 1963(Mackay, , 1983bMackay and Dallimore, 1992). The creep pattern, measured to a depth of 25 m, has displayed a quasi-sinusoidal downslope movement with significant upslope movement during the late winter and early summer.…”

Lake stratigraphy implies an 80 000 yr delayed melting of buried dead ice in northern Russia

“…frozen ground water (cf. Mackay and Dallimore, 1992), we believe it was more likely to be buried glacier ice, because the lake basins are so deep and located proximal to moraines. Further indications of glacial thermokarst are that Lake Kormovoye is topographically controlled by morainic ridges, and that Lyadhei-To is surrounded by kames.…”