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| Titel |
Sedimentary Facies and their possible significance in Holocene paleoclimate reconstruction: Example of Baraila Tal, Central Ganga Plains |
| VerfasserIn |
Pavani Misra, Rajiv Sinha, Sampat Kumar Tandon |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250121548
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| Publikation (Nr.) |
 EGU/EGU2016-320.pdf |
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| Zusammenfassung |
| To seek insights into natural climate variability on decadal/ centennial or half-millennial
scale, we need to examine Holocene stratigraphic records. Due to the paucity of
high-resolution Holocene continental records in India, Holocene climate change has mostly
been studied from the marine sediments. Since agricultural communities are sustained by the
resources of large river basins, it is important to understand the response of these systems
directly to any climate change. The fluvial archive itself offers a relatively low resolution
record, but the ox-bows and meander cut-offs in these basins act as semi-closed systems and
hence offer the possibility of obtaining better time resolved stratigraphic data. Therefore,
lakes from Central Ganga Plains can be regarded as good terrestrial archives; these have
been inadequately investigated as compared to the lakes in western India which
have been studied with multi-proxy approaches and show major abrupt climatic
disruptions.
Previous work on some of the lakes in the Central Ganga Plains is largely based on fossil
pollen and commonly shows an alternating increase in tree pollen and grassland pollen
representing a shifting trend of warm and humid conditions (from 12,500 to 6,400 and
4,800 to 2000 cal yrs BP), to cold and dry spells, respectively. Lake organic facies from
Sanai Tal follow an increasing trend of δ13C values from 15,000 to 5,800 14C yr BP, which
indicate an enhanced aquatic productivity during that period, except between 11,500 to
10,500 14C yr BP when lighter δ13C values are observed (Sharma et al., 2004), indicating a
dry climate for this short period.
Against the above background of previous studies, the Baraila Tal, a lake in the Central
Ganga Plains has been chosen to obtain a relatively better time-resolved stratigraphy and to
characterize its lithofacies for assessing proxy-paleoclimatic data. We have carried out
sedimentary facies analysis for three trenches in the Baraila Tal; the major sand, silt and clay
facies are subdivided into 21 sub-facies. One of the trenches has been studied for its clay
mineralogy, TOC and grain size distribution, using XRD, Rock Eval pyrolysis and the wet
sieving method, respectively. High resolution chronology will be based on AMS C-14
dates. These data will then be assessed for their utility as proxy-indicators of past
climate.
Reference: Sharma S., Joachimski M., Sharma M., Tobschall H.J., Singh I.B., Sharma C.,
Chauhan M.S., Morgenroth G., 2004. Lateglacial and Holocene environmental
changes in Ganga plain, Northern India. Quaternary Science Review, 23: 145-159 |
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