Terrestrial ecosystems on a Greenhouse Earth : climate and vegetation in the high southern latitudes during the early Paleogene

• Main Author: Contreras Arias, Lineth
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2015
• Subjects: ddc:550; Antarc*; Antarctic; Antarctica; East Antarctica; Wilkes Land
• Online Access: http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/38089; https://nbn-resolving.org/urn:nbn:de:hebis:30:3-380894; http://publikationen.ub.uni-frankfurt.de/files/38089/PhD_thesis_Contreras_L.pdf

Terrestrial climate and ecosystem evolution during ‘Greenhouse Earth’ phases of the early Paleogene remain incompletely known. Particularly, paleobotanical records from high southern latitudes are giving only limited insights into the Paleocene and early Eocene vegetation of the region. Hence, data from continuous well-calibrated sequences are required to make progress with the reconstruction of terrestrial climate and ecosystem dynamics from the southern latitudes during the early Paleogene. In order to elucidate the terrestrial conditions from the high southern latitudes during the early Paleogene, terrestrial palynology was applied in the present study to two well-dated deep-marine sediment cores located at the Australo-Antarctic region: (i) IODP Site U1356 (Wilkes Land margin, East Antarctica) and (ii) ODP Site 1172 (East Tasman Plateau, southwest Pacific Ocean). The studied sequence from IODP Site U1356 comprises mid-shelfal sediments from the early to middle Eocene (53.9 – 46 million years ago [Ma]). For the ODP Site 1172, the studied succession is characterized by sediments deposited in shallow marine environments of the middle Paleocene to the early Eocene (60.7 – 54.2 Ma). Based on the obtained pollen and spores (sporomorphs) results from the studied sequences of Site U1356 and Site 1172, this study aims to: (1) decipher the terrestrial climate conditions along the Australo-Antarctic region from the middle Paleocene to the middle Eocene; (2) evaluate the structure, diversity and compositional patterns of forests that throve in the Australo-Antarctic region during the early Paleogene; (3) understand the response of forests from the high southern latitudes to the climate dynamics from the early Paleogene; (4) establish a connection between the generated terrestrial palynomorph data and published Sea Surface Temperatures (SSTs) from the same cores. To decipher the terrestrial climatic conditions on the Australo-Antarctic region, this study relies on the nearest living relative (NLR) concept that assumes ...