6. Conclusions
Integration of the multiple datasets in the three GCs permitted the
identification of the direct link between delta landscape and vegetation
dynamics in the eastern (GC1), central (GC2), and western (GC3) parts of
the Late Quaternary Niger Delta. The study clearly identified two
time-bound stages (1 and 2) of delta evolution as inputs for
interpreting seasonal variations in climate and sea level change. The
major findings are as follow:
- Stage 1 linked the period from 20-11.7 ka to higher influx of
hinterland pollen, slow sedimentation on the prodelta, sea level fall.
and drier climate in the Niger Delta.
- Stage 2 (11.7-6.5 ka) indicated a phase of expansion of the littoral
realm/mangrove vegetation, higher sedimentation rate on the delta
front, sea level rise, and warm climate.
- The changes in the geochemical ratios during the two phases of
sedimentation provided the first clarification on the timing between
seasonal variation in vegetation, sediment supply, and
palaeoenvironmental settings (lower / upper shoreface) in the Niger
Delta.
- Sea level change was apparently the major driver in the evolution of
the Niger Delta based on the dominance of Rhizophora pollen
recorded from the GCs during stage 2.
- The integrated datasets (e.g., mangrove and hinterland pollen,
planktonic foraminifera, trace elemental ratios)
provided a robust and coherent
information for delineating the MIS2 (late glacial) and MIS1
(interglacial) boundary.