Filter Results
3301 results
  • Journal of Quaternary Science
    Data Types:
    • Other
    • Collection
  • Abstract: The pollen record of three marine late Quaternary cores off Senegal shows a juxtaposition of Mediterranean, Northern Saharan, Central Saharan elements, which are considered transported by the trade winds from a winter-rainfall area, and Sahelian, Soudanese, Soudano-Guinean elements, considered transported both by winds and mostly by the Senegal River, and coming from the monsoonal, summer tropical rainfall area of southern West Africa. Littoral vegetation is either the edaphically dry and saline Chenopodiaceae from sebkhas at the time of the main regression, or the warm tropical humid mangrove with Rhizophora during the humid optimum period. Four stratigraphic zones reflect, from basis to top: Zone 4. A semi-arid period with a balanced pollen input. Zone 3. A very arid period with the disappearance of monsoonal pollen, probably from the disappearance of the Senegal River, a very saline littoral plain with Chenopodiaceae, a larger input of northern Saharan pollen from intensified trade winds. Zone 2. A quite humid period, much more so than today, very suddenly established, with a northward extension of the monsoonal areas, a rich littoral mangrove, and weakening of the trade winds. Zone l. A slow and steady evolution toward the present semi-humid conditions with regression of the mangrove, and of the monsoonal areas toward the south. Tentative datations and correlations with the Tchad area suggested: zone 4: 22,500 to 19,000 years BP; zone 3: 19,000 to 12,500 years BP; zone 2: 12,500 to 5,500 years BP; zone 1: 5,500 years BP to top of core. Dinoflagellate cysts display a tropical assemblage with mostly estuarine neritic elements and also a weak oceanic component, mostly in the lower slope core 47. Cosmopolitan taxa dominate the assemblage and only a few species point to more specialized environments. Quantitative variations of the assemblage are the basis of stratigraphy which is not similar to the pollen stratigraphy, and an inshore-outshore gradient has to be taken into account to correlate the three cores. Category: geoscientificInformation Source: Supplement to: Rossignol-Strick, Martine; Duzer, Daniele (1979): Late Quaternary pollen and dinoflagellate cysts in marine cores off West Africa. Meteor Forschungsergebnisse, Deutsche Forschungsgemeinschaft, Reihe C Geologie und Geophysik, Gebrüder Bornträger, Berlin, Stuttgart, C30, 1-14 Supplemental Information: Not Availble Coverage: EVENT LABEL: * LATITUDE: 15.443333 * LONGITUDE: -17.306667 * DATE/TIME: 1971-01-01T00:00:00 * ELEVATION: -625.0 m * LOCATION: East Atlantic * CAMPAIGN: M25 * BASIS: Meteor (1964) * METHOD|DEVICE: Kasten corer EVENT LABEL: * LATITUDE: 15.480000 * LONGITUDE: -17.360000 * DATE/TIME: 1971-11-17T00:00:00 * ELEVATION: -945.0 m * Recovery: 5.5 m * LOCATION: East Atlantic * CAMPAIGN: M25 * BASIS: Meteor (1964) * METHOD|DEVICE: Kasten corer EVENT LABEL: * LATITUDE: 15.825000 * LONGITUDE: -17.861667 * DATE/TIME: 1971-11-17T00:00:00 * ELEVATION: -2576.0 m * Recovery: 6 m * LOCATION: East Atlantic * CAMPAIGN: M25 * BASIS: Meteor (1964) * METHOD|DEVICE: Kasten corer
    Data Types:
    • Other
    • Collection
  • A dataset containing 301 species occurrences available in GBIF matching the query: DatasetKey: (Appendix 4, Table 4) Relative abundances of benthic foraminifera in Late Quaternary sediments of core RC09-150 in the southeast Indian Ocean. The dataset includes 301 records from 1 constituent datasets: 301 records from (Appendix 4, Table 4) Relative abundances of benthic foraminifera in Late Quaternary sediments of core RC09-150 in the southeast Indian Ocean. Data from some individual datasets included in this download may be licensed under less restrictive terms.
    Data Types:
    • Dataset
  • A dataset containing 51 species occurrences available in GBIF matching the query: DatasetKey: (Table 4) Principal component analysis, paleotemperatures and distribution of infaunal benthic foraminifera in Late Quaternary sediments of core RC09-150 in the southeast Indian Ocean. The dataset includes 51 records from 1 constituent datasets: 51 records from (Table 4) Principal component analysis, paleotemperatures and distribution of infaunal benthic foraminifera in Late Quaternary sediments of core RC09-150 in the southeast Indian Ocean. Data from some individual datasets included in this download may be licensed under less restrictive terms.
    Data Types:
    • Dataset
  • A dataset containing 358 species occurrences available in GBIF matching the query: DatasetKey: (Appendix 3, Table 4) Relative abundances of benthic foraminifera in Late Quaternary sediments of core BMR96GC21 in the southeast Indian Ocean. The dataset includes 358 records from 1 constituent datasets: 358 records from (Appendix 3, Table 4) Relative abundances of benthic foraminifera in Late Quaternary sediments of core BMR96GC21 in the southeast Indian Ocean. Data from some individual datasets included in this download may be licensed under less restrictive terms.
    Data Types:
    • Dataset
  • A dataset containing 56 species occurrences available in GBIF matching the query: DatasetKey: (Table 4) Principal component analysis, paleotemperatures and distribution of infaunal benthic foraminifera in Late Quaternary sediments of core BMR96GC21 in the southeast Indian Ocean. The dataset includes 56 records from 1 constituent datasets: 56 records from (Table 4) Principal component analysis, paleotemperatures and distribution of infaunal benthic foraminifera in Late Quaternary sediments of core BMR96GC21 in the southeast Indian Ocean. Data from some individual datasets included in this download may be licensed under less restrictive terms.
    Data Types:
    • Dataset
  • Abstract: The ratio between the clay minerals kaolinite and chlorite has been investigated in high resolution in a late Quaternary sediment core from the central Aegean Sea. The record spans the last ca. 105 ka. The kaolinite/chlorite ratio was used to reconstruct the fine-grained aeolian dust influx from the North African deserts, mainly derived from desiccated lake depressions. It therewith can be used as a proxy for wind activity, aridity and vegetation cover in the source area. The data document three major humid phases in North Africa bracketing the formation of sapropel layers S4, S3 and S1. They occur at >105-95 ka, 83.5-72 ka and 14-2 ka. The first two phases are characterised by relatively abrupt lower and upper boundaries suggesting a non-linear response of vegetation to precipitation, with critical hydrological thresholds. In contrast, the onset and termination of the last humid period were more gradual. Highest kaolinite/chlorite ratios indicating strongest aeolian transport and aridity occur during Marine Isotope Stage (MIS) 5b, at ca. 95-84 ka. The long-term decrease in kaolinite/chlorite ratios during the last glacial period indicates a gradual decline of deflatable lake sediments in the source areas. Category: geoscientificInformation Source: Supplement to: Ehrmann, Werner; Seidel, Martin; Schmiedl, Gerhard (2013): Dynamics of Late Quaternary North African humid periods documented in the clay mineral record of central Aegean Sea sediments. Global and Planetary Change, 107, 186-195, https://doi.org/10.1016/j.gloplacha.2013.05.010 Supplemental Information: Not Availble Coverage: EVENT LABEL: (GeoTü SL143) * LATITUDE: 38.261830 * LONGITUDE: 25.103170 * ELEVATION: -665.0 m * LOCATION: Aegean Sea * DEVICE: Gravity corer (Kiel type)
    Data Types:
    • Tabular Data
    • Dataset
  • Response of deep-sea benthic foraminifera to Late Quaternary climate changes, southeast Indian Ocean, offshore Western Australia
    Data Types:
    • Tabular Data
    • Dataset
  • Paleoenvironmental Reconstructions from Marine Sediments @ AWI
    Data Types:
    • Collection
  • South Atlantic in Late Quaternary: Reconstruction of Budget and Currents
    Data Types:
    • Collection