Indications of Recent Extensive Glacierization in North–Central Baffin Island, N.W.T.

Abstract

AbstractStudies of the geomorphology and rock lichen development north of the Barnes Ice Cap prompt the conclusion that 70 per cent of this extensive, interior region was covered by permanent ice some 300 to 400 yr. ago. Contemporaneously the northern Barnes Ice Cap was significantly larger than today; it dammed up a lake in the upper Isortoq valley, over 80 km. long and up to 300 m. deep. Excluding the ice cap less than 2 per cent of the area is glacierized today; this represents a dramatic reduction in surface area of the former ice cover. Similarly, significant recession of the ice cap implies that glaciers of the “Baffin type” are in a less healthy budgetary state than hitherto has been assumed.Proof of former extensive ice cover rests largely upon restricted rock lichen development. When sufficient time has elapsed for complete colonization, few indications of the former existence of an ice cover will remain. This type of glacierization may have affected large areas in the high Arctic. Absence of evidence ofglaciation, therefore, cannot be relied upon to delimit nunatak areas (plant refugia) during the last glaciation.