• Login
    View Item 
    •   DSpace Home
    • Institute's contributions
    • Scholarly literature
    • View Item
    •   DSpace Home
    • Institute's contributions
    • Scholarly literature
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Supra-generic radiolarian transfer function based late Miocene palaeomonsoonal changes in the northeastern tropical Indian Ocean

    No Thumbnail [100%x80]
    View/Open
    Bull_Indian_Geol_Assoc_28_29.pdf (1.068Mb)
    Date
    1995
    Author
    Gupta, S.M.
    Fernandes, A.A.
    Metadata
    Show full item record
    Abstract
    A Q-mode factor analysis of the % data of 25 broadly defined supra-generic radiolarian groups in 42 deep-sea surface sediments produced four statistically significant and geographically distinct faunal assemblages related to (1) southwest cooler (27 degrees C), hypersaline (34.5 ppt) and highly productive (0.3 mgC/m sup(3)/d); (2) northeastern warmer (27 degrees C), hyposaline (34.5 ppt) and poor productive (0.2 mgC/m sup(3)/d); (3) transitional and (4) southern water masses during southwest monsoon in the central Indian Ocean. The southwest hypersaline and northeast hyposaline faunal assemblages are separated by a transitional assemblage that divides the Central Indian Ocean Basin diagonally along the 34.5 ppt isohaline south of Sri Lanka. The southern factor dominates the area influenced by the 10-12 degrees S hydrographic front. Resultant transfer functions have multiple correlation coeflicients (r) at 0.001 level of significance (99.9%) for the salinity, PPT and SST for the southwest monsoon only. Descending trend in the correlation coefficients for the salinity-July-August (r=0.834), PPT-SWM (r=0.785) SST-spring (May-July) (r=0.695) suggests order of the faunal sensitivity in the area and their respective reliabilities in the paleoestimates. SST and PPT changes using % data of the late Miocene radiolarian sequence from the Sawai Bay Formation, Neill Island, Andamans. Estimated SST and salinity during southwest monsoon are not only conformable with the qualitative paleoceanography in terms of warmer periods (W) of W-9 and W-11, but also have resolved W-8 and W-10 in late Miocene Neill Island radiolarian data-set. Salinity minima in warmer and maxima in colder periods reflect the influx of fresh water from the Ganges-Bramhputra rivers into the Bay of Bengal during southwest monsoon.
    URI
    http://drs.nio.org/drs/handle/2264/2371
    Collections
    • Scholarly literature [9074]

    DSpace software copyright © 2002-2016  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    Atmire NV
     

     

    Browse

    All of DSpaceCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    LoginRegister

    DSpace software copyright © 2002-2016  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    Atmire NV
     

     

    NoThumbnail