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velocity and the PC1 score of the geochemical XRF data (standing for the relation
between pelagic and terrigenous deposition). Time series of climatic phenomena
contain periodic components related to forcing at a wide range of time scales -
from decades to millennia. The (core) depth to time transformation of the data is the
main prerequisite for a time series analysis.
Figure 5.13 shows the variables' p-wave velocity of core 211660-5 and PC1-
score of XRF data of core 303610-12 as time series after depth to time transforma-
tion. Additional columns summarize results from paleo-environmental reconstruc-
tions based on geochemical and diatom analyses. In Fig. 5.14 the spectral densities
are displayed. As in particular the dating of Littorina Sea sediments are regarded
uncertain in detail (Sect. 5.5.1) we do not interpret here the high-frequency periodic-
ities, but concentrate instead on centennial scale periods where smaller uncertainties
in the age model can be neglected.
In a previous study (Kotov and Harff 2006 ) , we have investigated the periodic-
ity in the grey scale values of colour scans of core 211660-5. The 900-year period
appeared to be the most prominent peak of spectral densities. Additionally the 400-
and 500-years periods were identified to be significant for the grey-scale time series
of core 211660-5. These results are confirmed by the analysis carried out here. The
Fig. 5.13 p-Wave velocities of core 211660-5, PC1 score of XRF data of core 303610-12 as
time series and paleo-environmental reconstruction based on sedimento-physical, geochemical,
and diatomological data interpretation
 
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