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  1. Book ; Online: Stable isotope and Mg/Ca record of Globigerinoides ruger morphotypes, supplementary data to: Steinke, Stephan; Chiu, Han-Yi; Yu, Pai-Sen; Shen, Chuan Chou; L?wemark, Ludvig; Mii, Horng-Sheng; Chen, Min-Te (2005): Mg/Ca ratios of two Globigerinoides ruber (white) morphotypes: Implications for reconstructing past tropical/subtropical surface water conditions. Geochemistry Geophysics Geosystems, 6, Q11005

    Steinke, Stephan / Chen, Min-Te / Chiu, Han-Yi / L?wemark, Ludvig / Mii, Horng-Sheng / Shen, Chuan Chou / Yu, Pai-Sen

    2005  

    Abstract: Tests of the planktonic foraminifer Globigerinoides ruber (white; d'Orbigny) have become a standard tool for reconstructing past oceanic environments. Paleoceanographers often utilize the Mg/Ca ratios of the foraminiferal tests for reconstructing low- ... ...

    Abstract Tests of the planktonic foraminifer Globigerinoides ruber (white; d'Orbigny) have become a standard tool for reconstructing past oceanic environments. Paleoceanographers often utilize the Mg/Ca ratios of the foraminiferal tests for reconstructing low-latitude ocean glacial-interglacial changes in sea surface temperatures (SST). We report herein a comparison of Mg/Ca measurements on sample pairs (n = 20) of two G. ruber (white) morphotypes (G. ruber sensu stricto (s.s.) and G. ruber sensu lato (s.l.)) from surface and downcore samples of the western Pacific and Indian Oceans. G. ruber s.s. refers to specimens with spherical chambers sitting symmetrically over previous sutures with a wide, high arched aperture, whereas G. ruber s.l. refers to a more compact test with a diminutive final chamber and small aperture. The G. ruber s.s. specimens generally show significantly higher Mg/Ca ratios compared to G. ruber s.l. Our results from the Mg/Ca ratio analysis suggest that G. ruber s.l. specimens precipitated their shells in slightly colder surface waters than G. ruber s.s. specimens. This conclusion is supported by the differences in delta18O and delta13C values between the two morphotypes. Although it is still unclear if these two morphotypes represent phenotypic variants or sibling species, our findings seem to support the hypothesis of depth and/or seasonal allopatry within a single morphospecies.
    Language English
    Dates of publication 2005-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Online
    Note This dataset is supplement to doi:10.1029/2005GC000926
    DOI 10.1594/PANGAEA.738255
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  2. Book ; Online: Oxygen isotope and Mg/Ca record of planktonic foraminifera of sediment core MD01-2390, supplementary data to: Steinke, Stephan; Chiu, Han-Yi; Yu, Pai-Sen; Shen, Chuan Chou; Erlenkeuser, Helmut; L?wemark, Ludvig; Chen, Min-Te (2005): On the influence of sea level and monsoon climate on the southern South China Sea freshwater budget over the last 22,000 years. Quaternary Science Reviews, 25(13-14), 1475-1488

    Steinke, Stephan / Chen, Min-Te / Chiu, Han-Yi / Erlenkeuser, Helmut / L?wemark, Ludvig / Shen, Chuan Chou / Yu, Pai-Sen

    2005  

    Abstract: Changes in the local freshwater budget over the last 22,000 years have been estimated from a sediment core located in the southern South China Sea (SCS) using a combined approach of Mg/Ca and oxygen isotopes on the planktonic foraminifera Globigerinoides ...

    Abstract Changes in the local freshwater budget over the last 22,000 years have been estimated from a sediment core located in the southern South China Sea (SCS) using a combined approach of Mg/Ca and oxygen isotopes on the planktonic foraminifera Globigerinoides ruber (white) sensu stricto (s.s.). Core MD01-2390 (06?28,12N, 113?24,56E; water depth 1591?m) is located near the glacial paleo-river mouths of the Baram, Rajang and North Sunda/Molengraaff Rivers that drained the exposed Sunda Shelf. The delta18Oseawater record reveals lower average values (-0.96?0.18 per mil) during the Last Glacial Maximum (LGM) when compared with modern values (-0.54?0.18 per mil). Low salinity during the LGM is interpreted to reflect a higher freshwater contribution due to a greater proximity of the core site to the mouths of the Baram, Rajang and North Sunda/Molengraaff Rivers at that time. A general deglacial increasing trend in salinity due to the progressive landward displacement of the coastline during deglacial shelf flooding is punctuated by several short-term shifts towards higher and lower salinity that are likely related to abrupt changes in the intensity of the East Asian summer monsoon. Thus, the deglacial delta18Oseawater changes reflect the combined effects of sea-level-induced environmental changes on the shelf (e.g. phases of retreat and breakdown of the shelf drainage systems) and East Asian monsoon climate change. Lower salinity than at present during the Early Holocene may be attributed to an increase in summer monsoonal precipitation that is corroborated by previous marine and terrestrial studies that report a Preboreal-Early Holocene monsoon optimum in the Asian monsoon region.
    Language English
    Dates of publication 2005-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Online
    Note This dataset is supplement to doi:10.1016/j.quascirev.2005.12.008
    DOI 10.1594/PANGAEA.738282
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

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