Geology Reference
In-Depth Information
growing”) (Richardson, 1851, p. 234; see Mackay, 1981c). Following upon the disappear-
ance of John Franklin's 1848-49 expedition to the Arctic and the numerous Franklin
searches and other expeditions in the subsequent decades, data on the depth of frost
penetration at various latitudes on the North American continent were published in a series
of reports by the Royal Geographical Society in Great Britain (Lefroy, 1887, 1889a, b).
The beginning of the twentieth century saw a sharp increase in knowledge concerning
the cold non-glacial regions of the world. This was the time of the 1898 Klondike gold
rush in northwestern Canada and the subsequent migration of many of its miners to
Alaska in 1901-1903. It was also the time of heroic exploration in Antarctica, culminating
in the race to reach the South Pole between Scott and Amundsen in 1910-11. Many of the
individuals involved in these historic activities made observations upon the frozen ground,
and the harsh, cold-climate conditions that they experienced.
In the Klondike, miners had to remove a frozen overburden (“muck”), often many
meters thick, in order to reach the placer gold that rested upon bedrock. Typically, a fi re
was built on the surface and the thawed ground beneath was progressively removed,
thereby creating vertical pits through to the underlying bedrock. Alternatively, streams
were damned and water diverted across the claim, thereby causing “natural thawing” of
the ground beneath. The early Canadian government geologists who were assigned to the
area reported typical rates of thaw of 5-10cm per day (McConnell and Tyrrell, 1898).
These methods, known as “frost prospecting,” were attributed to earlier Russian mining
practices in the Ural Mountains (Perrett, 1912). Later, steam thawing was used. Ulti-
mately, the most effi cient method of thawing frozen ground was found to be through the
application of cold running water (Weeks, 1920). The relevance of these early mining
experiences to our understanding of thermokarst and related processes is now obvious
but at the time, seemed obscure.
In Antarctica, the scientifi c reports prepared by members of the heroic expeditions
are also of great interest. For example, there is considerable anecdotal evidence concern-
ing the exceptional strength of the katabatic winds blowing off the Antarctic ice sheet.
C. E. Borchgrevink (1901, pp. 128, 140) fi rst commented on the ability of strong and per-
sistent wind to transport sediment particles, small boulders, and even objects such as
heavy boots, over considerable distances. Observations by members of Scott's Northern
Party, who spent two winters of incredible hardship in Northern Victoria Land in 1910 -11,
confi rm this: “pebbles were fl ying about the beach like small bullets . . .” and “the sea ice
was strewn with pebbles up to half an inch in diameter” (Priestley, 1914, p. 139). Almost
certainly, comments like these contributed to a general acceptance of the importance of
wind in periglacial environments. R. E. Priestley was also the fi rst to record, in popular
writing (Priestley, 1914, p. 290), the audible sound of thermal-contraction cracking, a
process that, a few years later, was to be corrected inferred as the cause of ice wedges in
northern Alaska (Leffi ngwell, 1915, 1919). Griffi th Taylor, another member of the 1910-13
British Antarctic Expedition, was the fi rst to describe the large polygons (“tesselations”)
of the McMurdo Sound region (Taylor, 1916, 1922) that were subsequently identifi ed as
sand wedges by T. L. Péwé (1959).
Given this context, it is not surprising that the periglacial concept was enthusiasti-
cally embraced by European geologists in the years following Lozinski's presentations
at Stockholm in 1910. Several infl uential benchmark papers soon followed. Cold-climate
patterned ground was described by W. Meinardus (1912) and the importance of frost-
shattering of rocks was highlighted by B. Högbom (1914).
Because of the inaccessibility of most northern regions at that time, it was perhaps
inevitable that periglacial geomorphology subsequently developed as a branch of a
European-dominated climatic geomorphology. The primary aims were Pleistocene
