Ancient Records of Active Temperate Glacier margins

As active temperate glaciers provide us with a clear impression of their former passage, their impacts on ancient glaciated terrains should be identifiable. One excellent example in western

Glacilacustrine silt and clay

Subglacial erosion

Fluvial deposition

Glacilacustrine silt and clay

Subglacial erosion

Fluvial deposition

Subaerial Depostion

Subaerial erosion

Subglacial erosion

Subaerial erosion

Fluvial deposition

Subglacial Erosion

Subglacial deposition Subglacial erosion

Glacilacustrine deposition

Subglacial deposition Subglacial erosion

Glacilacustrine deposition

Canada has been identified by Evans et al. (1999a). In an extensive area deglaciated by the westernmost ice lobe of the southwest Laurentide Ice Sheet, between Calgary and Granum, Alberta, numerous closely spaced, low-amplitude moraine ridges drape fluted terrain and demarcate active ice-marginal recession over a distance of 90 km (Fig. 2.18a, b). Similar active recession appears to have characterized the margin of the adjacent 'central' lobe in southern Alberta. Here a 50 km wide belt of low-amplitude moraine ridges stretch largely unbroken over

Deglaciated Iceland
Figure 2.17 Models of glacifluvial and glacilacustrine deposition based upon the Malaspina Glacier, Alaska; (see text for explanation). (After Gustavson and Boothroyd, 1987).

130 km through the Milk River drainage basin and lie inside a broad arc of overridden thrust moraines (Fig. 2.18c). Similar recessional push moraines have been identified in Wisconsin, USA by Ham and Attig (2001), who make comparisons with Icelandic push moraines and, as a consequence, propose that the former Wisconsin Valley glacier lobe underwent active recession during the initial stages of deglaciation. Landform records of active temperate snouts exist in the lowlands bordering the mountain terrain of the Southern Alps in New Zealand. Here glacier ice has left a series of low-amplitude push moraines superimposed on a larger ridge of glacitectonized lake sediment that dams the southern shore of Lake Pukaki (Fig. 2.19).

Project Management Made Easy

Project Management Made Easy

What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.

Get My Free Ebook


Post a comment