1992/06/01 by Jenny Mackay, S R Dallimore · 2 citations
Earth and Planetary Sciences · Environmental Science · #Climate change and permafrost #Methane Hydrates and Related Phenomena #Geology and Paleoclimatology Research #Geology #Meltwater #Ice tongue #Ice divide #Geomorphology #Permafrost #Ice wedge #Arctic ice pack #Ice stream #Ice shelf #Ice sheet #Glacier #Arctic #Antarctic sea ice #Sea ice #Oceanography #Cryosphere
paper · doi:10.1139/e92-099
openalex publication_date 1992/06/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/11
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 δ 18 O 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 δ 18 O 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 δ 18 O 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.