Junttila, Juho (2007): Clay minerals in response to mid-Pliocene glacial history and climate in the polar regions (ODP, Site 1165, Prydz Bay, Antarctica and Site 911, Yermak Plateau, Arctic Ocean)

Leg/Site/Hole:
ODP 151
ODP 188
ODP 188 1165
ODP 151 911
Identifier:
2009-009900
georefid

0355-3191
issn

AUOGAQ
coden

978-951-42-8367-3
isbn

Creator:
Junttila, Juho
University of Oulu, Oulu, Finland
author

Identification:
Clay minerals in response to mid-Pliocene glacial history and climate in the polar regions (ODP, Site 1165, Prydz Bay, Antarctica and Site 911, Yermak Plateau, Arctic Ocean)
2007
Acta Universitatis Ouluensis. Series A, Scientiae Rerum Naturalium
Oulun Yliopisto, Oulu, Finland
481
48 pp.
This thesis examines the Mid-Pliocene climatic extreme ca. three million years ago (Ma) which was the latest longtime warm period. It is an important topic because the climate back then was warmer compared with the present. The bipolar regions are studied because they represent the largest areas that control the global climate. This study is based on clay mineral research that may significantly improve our knowledge of the Mid-Pliocene climate when combined with other palaeoenvironmental data. The paleoclimatological objectives of this study were: 1) to investigate how clay minerals reflect the Mid-Pliocene Global Warmth event, 2) to study ice sheet development at high latitudes, especially in East-Antarctica, and the history of ice rafting and sea ice, especially in the Arctic Ocean. This thesis deals with the clay mineral distribution and compositional analysis of the Pliocene-aged marine sediment sequences provided by the Ocean Drilling Program (ODP). The first studied site, Site 1165, is located at the continental rise of Prydz Bay, East Antarctica, and the second studied site, Site 911, is located at the Yermak Plateau, north of Svalbard, in the Arctic Ocean. The Pliocene smectite clay minerals at Site 1165 were mainly derived from Antarctic continental sources and transported to the site primarly by bottom currents related to warm events during the last 5 Ma. The evidence obtained in this study shows that the East Antarctic ice sheet may have been a dynamic ice sheet during the past 5 Ma, especially during the Mid-Pliocene. The results from the Mid-Pliocene possibly suggest a general warming trend. Based on the composition of the heavy minerals and clay minerals, at Site 911, the Pliocene smectite clay minerals were mainly transported within sea ice by the Siberian branch of the Transpolar Drift. The results indicate a warming trend at approximately 3 Ma after which they indicate a shift back to glacial conditions. Based on this study, the Mid-Pliocene Global Warmth can be observed in both the Arctic and Antarctic regions.
Coverage:Geographic coordinates:
North:80.2829
West:8.1338East: 67.1400
South:-64.2300

Stratigraphy; Antarctica; Arctic Ocean; Cenozoic; clay minerals; climate change; dynamics; East Antarctica; glacial geology; heavy minerals; ice; ice rafting; ice sheets; Leg 151; Leg 188; marine sediments; middle Pliocene; Neogene; Ocean Drilling Program; ODP Site 1165; ODP Site 911; paleoclimatology; Pleistocene; Pliocene; Prydz Bay; Quaternary; sea ice; sediment transport; sediments; sheet silicates; silicates; Southern Ocean; Tertiary; Yermak Plateau;

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