• Login
    View Item 
    •   DSpace Home
    • Institute's contributions
    • Scholarly literature
    • View Item
    •   DSpace Home
    • Institute's contributions
    • Scholarly literature
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Glacial-Holocene climate-driven shifts in lacustrine and terrestrial environments: Rock magnetic and geochemical evidence from East Antarctic Mochou Lake

    Thumbnail
    View/Open
    Palaegeo_Palaeoeclim_Palaeoecol_576_110505a.pdf (2.759Mb)
    Date
    2021
    Author
    Noronha-DeMello, C.A.
    Nair, A.
    Mahesh, B.S.
    Warrier, A.K.
    Mohan, Rahul
    Kurian, S.
    Metadata
    Show full item record
    Abstract
    Geomorphic reconstructions of the East Antarctic Ice Sheet history across Antarctica suggest diachronous and varying retreat patterns with changing climate. However, little is known of how terrestrial environments responded to these climate changes because the continental ice sheet covered most Antarctic coastal oases during the Last Glacial Maximum (LGM), eliminating terrestrial records. In this study, the environmental history spanning the last 25,400 years was reconstructed using geochronology, lithology, rock magnetism and geochemistry to understand the effect of glacial-deglacial climate variations on surface processes and Mochou Lake ecology. During the last glacial period (25.4 to 18.8 cal. kyr BP), intensified winds and the freeze-thaw action of ice actively weathered the high elevation western catchment that was a dominant sediment source to the lake. The glacial environmental conditions induced a persistent perennial lake ice-cover resulting in anoxia, low sedimentation, primary production and weak brackish conditions. Progressively, as deglacial conditions augmented around 18.8 cal. kyr BP, increased catchment meltwater flow enhanced sediment transport and also transformed the lake into a freshwater basin, although perennial ice-cover still prevailed. Further, the biotic development of the lake began later in the Mid-Holocene as compared to other lakes in the region, wherein the seasonal lake ice cycle and/or ice moat developed. Weak chemical weathering and pedogenesis also commenced in the catchment in response to the warming climate trend. This delayed response to the Holocene warming was possibly due to the local cooling effect of the D�lk Glacier�s discharge that also led to sea-ice persistence in the Prydz Bay. This study also provides further evidence that parts of the Larsemann Hills remained free of erosive grounded ice during the LGM and subsequent deglaciation. The Mirror Peninsula, specifically, escaped ice overriding despite being enclosed by the D�lk Glacier, Lake Nella ice lobe and Amery Ice Shelf.
    URI
    https://doi.org/10.1016/j.palaeo.2021.110505
    https://drs-beta.nio.org/drs/handle/2264/8671
    Collections
    • Scholarly literature [9074]

    DSpace software copyright © 2002-2016  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    Atmire NV
     

     

    Browse

    All of DSpaceCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    LoginRegister

    DSpace software copyright © 2002-2016  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    Atmire NV