Correlation of late Miocene to Pliocene climatic events in Antarctic drill sites using physical properties data

Author(s): Williams, Trevor; Escutia, Carlota; McKay, Robert; Passchier, Sandra; van de Flierdt, Tina; Tauxe, Lisa; Jimenez-Espejo, Francisco; Jairo González, Jhon
Author Affiliation(s): Primary:
Lamont-Doherty Earth Observatory, New York, NY, United States
Instituto Andaluz de Ciencias de la Tierra, Spain
Victoria University of Wellington, New Zealand
Montclair State University, United States
Imperial College London, United Kingdom
Scripps Institution of Oceanography, United States
Volume Title: 34th international geological congress; abstracts
Source: International Geological Congress [International Geological Congress, Abstracts = Congrès Géologique International, Résumés, Vol.34, p.2762; 34th international geological congress, Brisbane, Queensl., Australia, Aug. 5-10, 2012. Publisher:], [location varies], International CODEN: IGABBY
Note: In English
Summary: Drilling by NDRILL into the sediments beneath the McMurdo Ice Shelf revealed repeated advance and retreat of the Ross Ice Shelf during the Pliocene, and related ice sheet modelling has shown that West Antarctica was mostly ice-free during the warm intervals. The alternating warm/cold paleoclimatic conditions that lead to these ice sheet dynamics are likely to have been felt across the whole Antarctic region, and should be represented at other drill sites around Antarctica. IODP Exp. 318 drilling on the Wilkes Land continental margin of East Antarctica obtained records of late Miocene to Pleistocene environmental change at Sites U1359 and U1361. Physical proper ties data measured on core and downhole, in particular bulk density and natural gamma radiation, reveal clear alternations between diatom-rich and terrigenous-rich intervals (diatom opal has a lower density and much lower natural radioactivity than clay minerals, and diatoms have a high internal porosity). Sites U1359 and U1361 record the same climate signal, with some minor differences due to local patterns of sediment accumulation. Diatom-rich intervals at Wilkes Land correspond to diatomites (warmer climate, less ice) at AND-1B, and some of the warm intervals can also be correlated to the Prydz Bay record at ODP Site 1165. At Wilkes Land, long-scale (100s of kyr) warm/cold alternations dominate, and have shorter-scale (Milankovitch obliquity/precession scale) superimposed.
Year of Publication: 2012
Research Program: IODP Integrated Ocean Drilling Program
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; ANDRILL; Algae; Antarctica; Cenozoic; Clastic rocks; Continental margin; Cores; Correlation; Diatomite; Diatoms; Expedition 318; Framework silicates; Glacial geology; IODP Site U1359; IODP Site U1361; Integrated Ocean Drilling Program; Leg 188; McMurdo Ice Shelf; Microfossils; Miocene; Neogene; ODP Site 1165; Ocean Drilling Program; Opal; Paleoclimatology; Plantae; Pleistocene; Pliocene; Prydz Bay; Quaternary; Ross Ice Shelf; Sedimentary rocks; Silica minerals; Silicates; Southern Ocean; Tertiary; Upper Miocene; Wilkes Land
Coordinates: S642300 S642200 E0671400 E0671300
S642434 S642434 E1435312 E1435312
S645415 S645415 E1435738 E1435738
Record ID: 2013078713
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