QUATERNARY CHANGES IN LEVEL OF THE UPPER TAYLOR GLACIER, ANTARCTICA -IMPLICATIONS FOR PALEOCLIMATE AND EAST ANTARCTIC ICE-SHEET DYNAMICS

Glacial drifts perched alongside outlet glaciers that drain through th e Transantarctic Mountains constrain inland polar plateau ice elevatio ns. The Taylor Glacier, which heads in the Taylor Dome (a peripheral d ome of the East Antarctic Ice Sheet), drains East Antarctic ice into t he Dry Valleys sector of Transantarctic Mountains and terminates in ce ntral Taylor Valley, about 24 km west of the Ross Sea. Five gravel-ric h drifts (including 39 distinct moraine ridges) fringe a lateral lobe of the Taylor Glacier in the lower Arena Valley, Quartermain Mountains , southern Victoria Land. He-3 and Be-10 exposure age dating (from Bro ok et al. 1992), together with Arena Valley stratigraphy and soil morp hologic data, provide chronologic control for these drifts and constra in maximum Quaternary thickening of the inland Taylor ice dome to less than 160 m. These minor Quaternary expansions of Taylor Glacier were out-of-phase with outlet glaciers that pass through the Transantarctic Mountains and terminate in the Ross Sea north and south of the Dry Va lleys region. Textural analyses suggest that drift deposition occurred from cold-based ice, even though Taylor Glacier advances most likely occurred during global interglaciations. The thermal regime of former Taylor Glacier ice lobes, the character of geomorphic features superim posed on individual drifts, the chemical composition of soils develope d on Taylor drifts, and the stability of in situ moraine ridges on ste ep valley walls suggest that the present cold-desert climate in Arena Valley has persisted for at least the last 2.2 Ma.