Till fabrics of the cross-valley moraines of north-central Baffin Island, Northwest Territories, Canada

Analyses of 103 till fabrics taken from proximal and distal slopes of cross-valley moraines in the Isortoq Valley show variations in fabric pattern with respect to slope and location within the valley. Four distinct morphological moraine types delineated are: simple-linear, s-shaped, hooked, and asymmetric. Analyses indicate hooked, asymmetric, and simple-linear moraines are formed by dissimilar processes or changes in intensity of the same process. S-shaped moraines differ morphologically from simple-linear but have the same fabric characteristics. Cross-valley moraines probably form at the base of an ice cliff grounded in a glacial lake. Influx of summer meltwater provides a trigger mechanism and explains association between moraines and water-deposited kame features. Asymmetric moraines were deposited by overriding and pushing; moraines at right angles to the ice cliff were formed by squeezing of till into basal crevasses or meltwater channels.