Evaluation of mumiyo deposits from East Antarctica as archives for the Late Quaternary environmental and climatic history.

Abstract

Mumiyo deposits form in the vicinity of snow petrel (Pagodroma nivea) nesting sites and consist of fossil stomach oil (mumiyo), guano and minerogenic material. Here, we evaluate mumiyo deposits from the inland mountain ranges of central Dronning Maud Land (DML) as high‐resolution archives for paleoenvironmental reconstructions in Antarctica. Investigation of internal structures and chemical composition shows that the lamination reflects progressive sedimentation, despite of the irregular outer morphology of the deposits. Detailed radiocarbon analysis demonstrates that stratigraphies are intact: 14C ages become successively younger upwards in the deposits. Fatty acid and n‐alcohol composition was determined on samples from eight mumiyo deposits. Dominance of low molecular weight compounds (C14 to C18) points to a dietary signal, however, the relatively low proportions of un‐saturated compounds compared to fresh stomach oils indicates some post‐depositional degradation. We found marine diatoms in the mumiyo, which are potentially a proxy for sea ice conditions in the foraging habitat of the petrels. Age ranges of the investigated deposits suggest occupation by snow petrels from 17 ka to > 58 ka. Changes in deposition rates point to higher occupation frequency in Petermann Range from 46 to 42 ka compared to the late marine isotope stage 3 (MIS3) and the Last Glacial Maximum (LGM).