In size eskers are highly variable. Two of the largest in Canada are the Thelon esker in the Northwest Territories and Nunavut (almost 800 km long) and the Munro esker near Munro Lake in northern Ontario (250 km long and almost 5 km wide). In contrast, many eskers are a few kilometres in length, approximately 100 m wide and up to 50 m high. One of the world's best areas to observe eskers is the mining region of northwest Québec, where many eskers, generally aligned north-south, were emplaced during the last deglaciation.
Eskers do not generally survive from one GLACIATION to another. They are features of a deglaciation phase and are usually destroyed when ice re-advances over them. Eskers form good, confined aquifers (water-bearing strata) when covered by fine, impermeable sediments. Esker sediments help locate ore deposits upstream from a ore-indicator-bearing esker bed (see PROSPECTING).
Author ROBERT J. ROGERSON
Links to Other Sites
A Journey to a New Land
A multimedia website about the arrival of early humans in the Americas. Features activities that help students learn about archaeological research techiques and discoveries. From the SFU Museum of Archaeology and Ethnology and the Virtual Museum of Canada.