A

Plate 38.9 (a) A swarm is spatially defined by longitudinal continuity lines, aligned to a visually coherent system of flow traces, and transverse up- and downstream boundaries. The latter are drawn transverse to continuity lines, if necessary in a stepped fashion. Those elements which allow definition of a swarm can be any geological features that reflect ice-flow direction (e.g. striae, flutes, till fabrics, glaciotectonic folds, etc.). (b) An example of an event swarm underlying the deglacial envelope. The angular difference between the flow indicators in the event swarm and the deglacial envelope will differ depending on location, and may be small or non-existent at some locations.

et al.1968, Aylsworth and Shilts 1989) creases with number of crossbars, redrawn from Lee (1959)

Glacial lineations, based on interpretation of Landsat MSS images

Esker, from Prest et al. (1968)

Outline of zone of overridden maginal moraines, from Kleman et al. (2002)

et al.1968, Aylsworth and Shilts 1989) creases with number of crossbars, redrawn from Lee (1959)

Glacial lineations, based on interpretation of Landsat MSS images

Esker, from Prest et al. (1968)

Outline of zone of overridden maginal moraines, from Kleman et al. (2002)

0 0

Post a comment