Use of soil chronosequences for testing the existence of high-water-level lakes in the McMurdo Dry Valleys, Antarctica

Abstract

Abstract In this study we utilize field observations and data collected from 190 pedons from Wright and Taylor Valleys to search for evidence of high-water-level lakes proposed to have existed during the Last Glacial Maximum and early Holocene (2.7–25.7 ka) in the McMurdo Dry Valleys. We hypothesize that soils above the uppermost paleo-lake level should be more strongly developed and contain more salts than soils below. During detailed mapping of soils in the Dry Valleys, we found no evidence of former lake sediments nor did we find high-level strandlines except for strandlines on the north valley wall ca. 50 m above Lake Vanda, ice-shove features, or paleo-shore features. However, there may have been minor expansions of major lakes in the McMurdo Dry Valleys. In central Taylor and Wright Valleys, soils on equivalent-aged drifts above and below the conjectured upper limits of Glacial Lakes Washburn (336 m) and Wright (550 m), respectively, are all well developed with no appreciable differences in their properties. Moreover, there were no significant differences in the slopes of regression equations relating soil property to age of the parent materials above and below the high-water lake levels.