The side growth of lithalsas : some comments on observations in Northern Québec
Belgium ; Canada ; Comparative study ; Geomorphogenesis ; Hautes-Fagnes ; Inheritated geomorphological features ; Lithalsa ; Palsa ; Periglacial features ; Permafrost ; Quebec
Based on observations in northern Québec and Belgium, the author infers that lithalsas in northern Québec are modern analogues of the enclosed and ramparted depressions that occur on the Hautes Fagnes plateau, Belgium. It is hypothesised
that the growth of these lithalsas occurs not only by vertical heave associated with ice segregation within mineral material but also by lateral frost thrusting.
Pingos, palsas and lithalsas : comparison with the Martian mounds
Arctic Region ; Belgium ; Canada ; Comparative study ; Geomorphogenesis ; Geomorphometry ; Hautes-Fagnes ; Lithalsa ; Mars planet ; Periglacial features ; Pingo
that are remnants of lithalsas in the Hautes-Fagnes (Belgium)suggest a similar origin. Pingos and lithalsas are formed on Earth under different climatic conditions, on Mars they could therefore reflect 2 generations of periglacial mounds and a significant change
Palsas, lithalsas and remnants of these periglacial mounds. A progress report
in the discontinuous permafrost zone. Lithalsas are similar mounds, but without any peat cover. Use of development and decay palsas as indicators of climatic change is difficult. The climatic conditions in which lithalsas form are much more restricted than those
for palsas. Some of the pingo remnants described in western Europe are, more accurately, lithalsa traces.
Remnants of lithalsas on the Hautes Fagnes plateau (Belgium) are on weathered quartzitic rocks
The ramparted depressions that exist on the Hautes Fagnes Plateau in Belgium, first interpreted in 1956 as the remnants of pingos are best explained as remnants of lithalsas (i.e., mineral palsas), formed from ice segregation within frozen ground
. The AA. demonstrate here that lithalsas were formed only on weathered quartzitic rocks of the Cambro-Ordovician massif of Stavelot, and probably are associated with local hydrological conditions.
Umiujaq, northern Québec : innovative techniques to monitor the decay of a lithalsa in response to climate change
The AA. describe the introduction of several new techniques to measure and monitor permafrost properties at a site near the east coast of the Hudson Bay, northern Quebec. Cores taken from the permafrost below the active layer of the lithalsa show
numerous oblique and fractured ice lenses indicative of extensive deformation of the lithalsa during its evolution. Examples of results of the new techniques applied in this study are provided. These techniques appear as very promising for permafrost
Internal structure of a lithalsa in the Akkol Valley, Russian Altai Mountains
Altai Mountains ; Asian part of Russia ; Geocryology ; Ice ; Lithalsa ; Periglacial features ; Permafrost ; Sedimentology ; Siberia ; Soil properties ; Stratigraphy
Perennial frost mounds are present near the edges of ponds located on the terrace between the mountain flank and a valley-bottom lake in the Akkol valley. The AA. describe one mound, identified as a lithalsa, which had been eroded so as to expose
Observations on the relationship between lake formation, permafrost activity and lithalsa development during the last 20 000 years in the Tso Kar Basin, Ladakh, India