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Hillenbrand, Claus-Dieter; Ehrmann, Werner (2005): Clay-mineral composition and biogenic opal content of Late Neogene to Quaternary sediments of the Antarctic Peninsula region. PANGAEA, https://doi.org/10.1594/PANGAEA.735191, Supplement to: Hillenbrand, C-D; Ehrmann, W (2005): Late Neogene to Quaternary environmental changes in the Antarctic Peninsula region: evidence from drift sediments. Global and Planetary Change, 45, 165-191, https://doi.org/10.1016/j.gloplacha.2004.09.006

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Abstract:
Clay-mineral composition and biogenic opal content in upper Miocene to Quaternary drift sediments recovered at two Ocean Drilling Program (ODP) sites from the continental rise in the Bellingshausen Sea had been analyzed in order to reconstruct the climatic and glacial history of the Antarctic Peninsula. The clay mineral composition at both sites is dominated by smectite, illite, and chlorite, and alternates between a smectite-enriched and a chlorite-enriched assemblage throughout the last 9.3 my. The spatial distribution of clay minerals in Holocene sediments west of the Antarctic Peninsula facilitates the identification of particular source areas, and thus the reconstruction of transport pathways. The similarity to clay mineral variations reported from upper Quaternary sequences suggests that the short-term clay-mineralogical fluctuations in the ODP cores reflect glacial-interglacial cyclicity. Thus, repeated ice advances and retreats in response to a varying size of the Antarctic Peninsula ice cap are likely to have occurred throughout the late Neogene and Quaternary. The clay minerals in the drift sediments exhibit only slight long-term variations, which are caused by local changes in glacial erosion and in supply of source rocks, rather than by major climatic changes.
The opal records at the ODP sites are dominated by long-term variations since the late Miocene. We infer that the opal content in the drift sediments, although it is influenced by dissolution in the water column and the sediment column and by the burial with lithogenic detritus, provides a signal of paleoproductivity. Because the annual sea-ice coverage is regarded as the main factor controlling biological productivity, the opal signal helps to reconstruct paleoceanographic changes in the Bellingshausen Sea. Slightly enhanced opal deposition during the late Miocene indicates slightly warmer climatic conditions in the Antarctic Peninsula area than at present. During the early Pliocene, enhanced opal deposition in the Pacific sector of the Southern Ocean and coinciding high opal concentrations in sedimentary sequences from the Atlantic and Indian sectors document a strong reduction of sea-ice cover and relatively warm climatic conditions. Thereby, the early onset of the Pliocene warmth in the Bellingshausen Sea points to a positive feedback of regional Antarctic climate on the global thermohaline circulation. A decrease of opal deposition between 3.1 and 2.6 Ma likely reflects sea-ice expansion in response to reduced supply of northern-sourced deep-waters to the Southern Ocean, caused by the onset of Northern Hemisphere glaciation. Throughout the Quaternary, a relatively constant level of opal deposition on the Antarctic continental margin indicates relatively stable climatic conditions.
Project(s):
Coverage:
Median Latitude: -66.491976 * Median Longitude: -12.750779 * South-bound Latitude: -68.531500 * West-bound Longitude: -78.487867 * North-bound Latitude: -64.372200 * East-bound Longitude: 30.643833
Date/Time Start: 1986-04-08T00:00:00 * Date/Time End: 1998-03-18T10:30:00
Event(s):
178-1095 * Latitude: -66.985400 * Longitude: -78.487867 * Date/Time: 1998-02-13T00:00:00 * Elevation: -3841.4 m * Penetration: 745 m * Recovery: 554.1 m * Location: South Pacific Ocean * Campaign: Leg178 * Basis: Joides Resolution * Method/Device: Composite Core (COMPCORE) * Comment: 72 cores; 662 m cored; 83 m drilled; 83.7% recovery
178-1096 * Latitude: -67.566817 * Longitude: -76.963517 * Date/Time: 1998-02-27T00:00:00 * Elevation: -3152.3 m * Penetration: 1009 m * Recovery: 673.3 m * Location: South Pacific Ocean * Campaign: Leg178 * Basis: Joides Resolution * Method/Device: Composite Core (COMPCORE) * Comment: 90 cores; 811.2 m cored; 197.8 m drilled; 83% recovery
178-1101A * Latitude: -64.372200 * Longitude: -70.261180 * Date/Time: 1998-03-18T10:30:00 * Elevation: -3279.7 m * Penetration: 217.7 m * Recovery: 215.75 m * Location: South Pacific Ocean * Campaign: Leg178 * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 24 cores; 217.7 m cored; 0 m drilled; 99.1 % recovery
Size:
11 datasets

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Datasets listed in this publication series

  1. Hillenbrand, C-D; Ehrmann, W (2005): Age reference and time scale for core PS1451-1. https://doi.org/10.1594/PANGAEA.218263
  2. Hillenbrand, C-D; Ehrmann, W (2005): Age reference and time scale for core PS1588-1. https://doi.org/10.1594/PANGAEA.218264
  3. Hillenbrand, C-D; Ehrmann, W (2005): Age reference and time scale for core PS1824-1. https://doi.org/10.1594/PANGAEA.218265
  4. Hillenbrand, C-D; Ehrmann, W (2005): Biogenic opal content of sediment core PS1451-1. https://doi.org/10.1594/PANGAEA.218260
  5. Hillenbrand, C-D; Ehrmann, W (2005): Biogenic opal content of sediment core PS1588-1. https://doi.org/10.1594/PANGAEA.218266
  6. Hillenbrand, C-D; Ehrmann, W (2005): Biogenic opal content of sediment core PS1588-3. https://doi.org/10.1594/PANGAEA.218267
  7. Hillenbrand, C-D; Ehrmann, W (2005): Biogenic opal content of sediment core PS1824-1. https://doi.org/10.1594/PANGAEA.218268
  8. Hillenbrand, C-D; Ehrmann, W (2005): Biogenic opal content of sediment core PS1824-2. https://doi.org/10.1594/PANGAEA.218270
  9. Hillenbrand, C-D; Ehrmann, W (2005): Clay mineral composition and biogenic opal content in upper Miocene to Quaternary drift sediments, ODP Site 178-1095. https://doi.org/10.1594/PANGAEA.218251
  10. Hillenbrand, C-D; Ehrmann, W (2005): Clay mineral composition and biogenic opal content in upper Miocene to Quaternary drift sediments, ODP Site 178-1096. https://doi.org/10.1594/PANGAEA.218252
  11. Hillenbrand, C-D; Ehrmann, W (2005): Lithogenic fraction and biogenic opal content, Hole 178-1101A. https://doi.org/10.1594/PANGAEA.218256