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The results of this dendrogeomorphological study provide evidence of the active movemerit of Hilda rock glacier, a tongue,shaped rock glacier in the Columbia Icefield region of Banff National Park. Cross-sectional samples were cut from 44 detrital subalpine fir (Abies lasiocarpa (Hook.) Nutt.) and Engelmann spruce (Picea engelmannii Parry) boles killed and buried by debris spilling off the steep distal slope of the rock glacier. The sampies were crossdated using locally and regionally developed tree-ring chronologies, and were shown to have been killed between 1576 and 1999. Our resuits show that Hilda rock glacier has advanced at an average rate of 1.6 cm/year since the late 1790s, with limited evidence of similar rates of activity extending back to the mid-1570s. This rock glacier activity is believed to be linked to persistent periglacial processes that appear to be independent of the climatic forcing mechanisms known to influence glacier mass balances over the same interval. [ABSTRACT FROM AUTHOR]

This paper presents data on and discusses the degree of postglacial stability of the northern Canadian tree limit. Holocene climatic changes have been both directional and synchronous for this region, though deteriorations/ameliorations either (1) lagged from west to east, (2) were buffered by local geographic factors, or (3) were not registered in the fossil record owing to the inherent persistence of the vegetation at some sites. The present northern tree limit in eastern Canada is in equilibrium with the prevailing climate, with the tree populations successfully regenerating both sexually and vegetatively. These tree stands are still occupying their maximum Hypsithermal positions. In contrast, the tree limit, tree line, and intervening forest-tundra ecotone in central and western Canada are out of equilibrium with today's climate. These populations are not sexually regenerative and apparently became established during warmer climates where the tree line was north of its present position. As such, they are susceptible to destruction by further climatic deterioration or anthropogenic disruption. [ABSTRACT FROM AUTHOR]

Multivariate statistical analyses allow specification of pollen-climate transfer functions useful in studies of paleoclimate. Two previously published models, when applied to two documented sites in Canada's District of Keewatin, produce inconsistent reconstructions of mean July temperatures for themed- to late-Holocene (approximately the past 5,000 years). The discrepancy between the results arises from differences in the construction of the functions. Of particular importance are the choice of pollen taxa included, and the sample provenances and the geographical range of the modern pollen data. A new model is developed with all-possible subsets regression, with due regard to the assumptions of the general linear model. Linear relationships between taxa abundances and summer temperature are specified, and multivariate outliers are removed. The paleotemperature records produced by the model for the two sites are consistent with the general features of previously reported work, and are more nearly similar to each other than reconstructions produced by the earlier, less sophisticated, models. [ABSTRACT FROM AUTHOR]

Cirques in the southern Canadian Cordillera are most numerous at lowest elevations and best developed on the north and northeastern flanks of mountains. Cirques at the heads of major valleys are generally at higher elevation, and are larger in area than cirques along the sides of valleys. The elevation frequency distribution is different for various types of cirque. Cirques which are well below mean cirque elevation are large and are almost always oriented to the north and northeast. Cirques well above mean cirque elevation are small and independent of orientation. A model is proposed in which cirque morphometry varies in a vertical plane in relation to the position of the snowline, and in a horizontal plane in relation to orientation. [ABSTRACT FROM AUTHOR]

Cirque floors increase in altitude toward the drier eastern parts of the Cordillera in southern British Columbia and Alberta, in a similar manner to the contemporary glaciation limit. Cirque floors are 100 to 400 m below the contemporary snowline. The relatively slight difference in elevation between the contemporary and cirque snowlines may possibly be attributed to a local decline in precipitation which partly compensated for the drop in temperature at the time of cirque formation. [ABSTRACT FROM AUTHOR]

Discusses the trend-surface analysis of two drumlin fields near Guelph, Ontario. Suggestion that drumlin elongation and size decline toward the margins of the fields; Random disturbance of the pattern resulting from local factors as land slope and drift depth; Morphological characteristics displayed by drumlin fields related to the decline of ice velocity and thickness toward the margins of an ice sheet.