Open AccessThe potential of perennial cave ice in isotope palaeoclimatology
Author(s) -
YONGE CHARLES J.,
MACDONALD WILLIAM D.
Publication year - 1999
Publication title -
boreas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.95
H-Index - 74
eISSN - 1502-3885
pISSN - 0300-9483
DOI - 10.1111/j.1502-3885.1999.tb00225.x
Subject(s) - geology , cave , ice core , δ18o , paleoclimatology , precipitation , antarctic sea ice , stable isotope ratio , cryosphere , physical geography , climatology , oceanography , climate change , sea ice , archaeology , geography , meteorology , physics , quantum mechanics
Perennial ice from caves on and to the east of the Canadian Great Divide yield δ 18 O and δD values, which are unusually high measurements when compared with the average precipitation for the region. Furthermore, these ice data fall below and along lines of lower slope than the Global Meteoric Water Line. To explain the observed relationships, we propose the following process. A vapour‐ice isotopic fractionation mechanism operates on warm‐season vapour when it precipitates as hoar ice on entering the caves. The subsequent fall of hoar to the cave floor through mechanical overloading, along with ice derived from ground‐water seepage (with a mean annual isotopic composition), results in massive ice formation of a mixed composition. This mixed composition is what is observed in the characteristic relationships found here. Such findings suggest that a warm versus cold climate interpretation for ancient cave ice may be the opposite of that found in the more familiar polar and glacial ice cores.