DOI: 10.5194/cp-14-1015-2018
Scopus记录号: 2-s2.0-85049851475
论文题名: Paleoceanography and ice sheet variability offshore Wilkes Land, Antarctica - Part 2: Insights from Oligocene-Miocene dinoflagellate cyst assemblages
作者: Bijl P.K. ; Houben A.J.P. ; Hartman J.D. ; Pross J. ; Salabarnada A. ; Escutia C. ; Sangiorgi F.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2018
卷: 14, 期: 7 起始页码: 1015
结束页码: 1033
语种: 英语
Scopus关键词: carbon dioxide
; chronostratigraphy
; climate variation
; dinoflagellate cyst
; glacial-interglacial cycle
; glaciation
; ice sheet
; Miocene
; Ocean Drilling Program
; Oligocene
; paleoceanography
; sea ice
; Antarctica
; East Antarctica
; Wilkes Land
; Dinophyceae
; Selenopemphix antarctica
英文摘要: Next to atmospheric CO2 concentrations, ice-proximal oceanographic conditions are a critical factor for the stability of Antarctic marine-terminating ice sheets. The Oligocene and Miocene epochs (∼ 34-5 Myr ago) were time intervals with atmospheric CO2 concentrations between those of present-day and those expected for the near future. As such, these past analogues may provide insights into ice-sheet volume stability under warmer-than-present-day climates. We present organic-walled dinoflagellate cyst (dinocyst) assemblages from chronostratigraphically well-constrained Oligocene to mid-Miocene sediments from Integrated Ocean Drilling Program (IODP) Site U1356. Situated offshore the Wilkes Land continental margin, East Antarctica, the sediments from Site U1356 have archived the dynamics of an ice sheet that is today mostly grounded below sea level. We interpret dinocyst assemblages in terms of paleoceanographic change on different timescales, i.e. with regard to both glacial-interglacial and long-term variability. Our record shows that a sea-ice-related dinocyst species, Selenopemphix antarctica, occurs only for the first 1.5 Myr of the early Oligocene, following the onset of full continental glaciation on Antarctica, and after the Mid-Miocene Climatic Optimum. Dinocysts suggest a weaker-than-modern sea-ice season for the remainder of the Oligocene and Miocene. The assemblages generally bear strong similarity to present-day open-ocean, high-nutrient settings north of the sea-ice edge, with episodic dominance of temperate species similar to those found in the present-day subtropical front. Oligotrophic and temperate surface waters prevailed over the site notably during interglacial times, suggesting that the positions of the (subpolar) oceanic frontal systems have varied in concordance with Oligocene-Miocene glacial-interglacial climate variability. © 2018 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109547
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Marine Palynology and Paleoceanography, Laboratory of Palaeobotany and Palynology, Department of Earth Sciences, Faculty of Geosciences, Utrecht University, P.O. Box 80.115, Utrecht, 3508 TC, Netherlands; Geological Survey of the Netherlands, Netherlands Organisation for Applied Scientific Research (TNO), Princetonlaan 6, Utrecht, 3584 CB, Netherlands; Paleoenvironmental Dynamics Group, Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 234, Heidelberg, 69120, Germany; Instituto Andaluz de Ciencias de la Tierra, CSIC-UGR, Armilla, 18100, Spain
Recommended Citation:
Bijl P.K.,Houben A.J.P.,Hartman J.D.,et al. Paleoceanography and ice sheet variability offshore Wilkes Land, Antarctica - Part 2: Insights from Oligocene-Miocene dinoflagellate cyst assemblages[J]. Climate of the Past,2018-01-01,14(7)