A Sr-Nd-Hf isotope characterization of dust source areas in Victoria Land and the McMurdo Sound sector of Antarctica

作者：Blakowski Molly A^*; Aciego Sarah M; Delmonte Barbara; Baroni Carlo; Salvatore Maria Cristina; Sims Kenneth W W

来源：Quaternary Science Reviews, 2016, 141: 26-37.

DOI：10.1016/j.quascirev.2016.03.023

• Dust
• Sr-Nd isotopes
• Nd-Hf isotopes
• Antarctica
• Paleoclimate

Determining the geographical provenance of dust provides crucial insight into the global dust cycle. For the East Antarctic Ice Sheet (EAIS), the importance of Southern hemisphere potential dust sources has been thoroughly investigated using radiogenic isotopes, whereas proximal dust source areas located on the periphery of the ice sheet remain poorly documented from a geochemical standpoint. In this work, we expand the existing isotopic (Sr-Nd) catalogue of dust and sand-sized sediments from Victoria Land and the McMurdo Sound sector, and incorporate Hf isotopic data to place additional constraints on dust source identification. The isotopic field for materials considered in this study is characterized by Sr-87/Sr-86 ratios ranging from 0.703 to 0.783, epsilon Nd between -12.01 and 6.36, and epsilon Hf from -16.77 to 6.89. As reported in previous works, the data reveal close relationships between Antarctic sediments and distinct parent lithologies; in addition, our findings emphasize the background presence of very fine dusts originating from dominant global sources and regional volcanic activity as barriers to direct source-to sink comparison of isotopic signatures. Thus, geochemical characterizations of dust sources to the Antarctic ice sheet involving multiple size fractions, including coarser-grained particles more susceptible to short-range transport, can help us to rule out global sources of dust when examining local sediment cores and ice cores.

• 出版日期2016-6-1