Physical properties and abundance of diatoms of the ANDRILL AND1-1B drill core

• Main Authors: Konfirst, Matthew Alan, Kuhn, Gerhard, Monien, Donata, Scherer, Reed P
• Format: Dataset
• Language: English
• Published: PANGAEA 2011
• Subjects: AND1-1B; AND-1B; ANDRILL; Antarctic Geological Drilling; D-ANDRILL; DRILL; Drilling/drill rig; McMurdo Ice Shelf; McMurdo Station; MIS; Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas; SPP1158; Antarctic; Arctic; Austral; Hut Point; Hut Point Peninsula; Ross Ice Shelf; Ross Island; Antarc*; Antarctica; Ice Shelf; Sea ice
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.757323; https://doi.org/10.1594/PANGAEA.757323

In the austral summer of 2006/7 the ANDRILL MIS (ANtarctic geological DRILLing- McMurdo Ice Shelf) project recovered a 1285 m sediment core from beneath the Ross Ice Shelf near Hut Point Peninsula, Ross Island, Antarctica in a flexural moat associated with the volcanic loading of Ross Island. Contained within the upper ~600 m of this core are sediments recording 38 glacial to interglacial cycles of Early Pliocene to Pleistocene time, including 13 discrete diatomite units (DU). The longest of these, DU XI, is ~76 m thick, contains two distinct unconformities marked by layers of volcanic brecciated sands, and has been assigned an Early to Mid-Pliocene age (5-3 Ma). A detailed record (avg. sample spacing of 33 cm) of the siliceous microfossil assemblages have been generated for DU XI and used in conjunction with geochemical and sedimentological data to subdivide DU XI into four discrete subunits of continuous sedimentation. Within each unit, changes in diatom assemblages have been correlated with the d18O record, providing a temporal resolution as high as 600 yr, and allowing for the construction of a detailed age model and calculation of associated sediment accumulation rates within DU XI. Results indicate a productivity-dominated sedimentary record with higher sediment accumulation rates containing a greater proportion of hemipelagic mud occurring during relatively cool periods and reduced accumulation during warmer intervals. This implies that even during periods of substantial warmth, Milankovitch-paced changes in Antarctic ice volume can be linked to ecological changes recorded as shifts in diatom assemblages.