Late Quaternary Climate Variations Reflected in Baltic Sea Sediments - The Baltic Sea Basin - page 108

Fig. 5.6 E-W echosounder - profile crossing the “master station” within the Eastern Gotland
Basin (sediment cores taken at the master station are marked)
cores. Geochemical and diatomological parameters have been used in particular
as proxies for the paleo-environmental interpretation. Table 5.1 gives an overview
about the variables measured including age models for each of the cores used in this
study.
5.4.3 Physical Properties
Non-destructive logging (p-wave velocity, wet bulk density, magnetic susceptibility)
of sediment cores was performed using a multi-sensor core logger (MSCL) from
GEOTEK Ltd., UK.
For more detailed information about multi-sensor core logging, see Boyce
( 1973 ) , Gunn and Best ( 1998 ) , Schultheiss and Weaver ( 1992 ) .
Sediment physical property data (see Figs. 5.7 and 5.8 ) have been used in this
chapter for core zonation, correlation, and interpretation of echosounder records.
As wet bulk density is sensitive to changes in the depositional regime, particularly
an increased input of sandy (terrigenous) particles will directly cause an increase in
density. A gradual decrease in density due to compaction occurs only in soft clay to
silt sediments (not in sands) and is easily recognized. Magnetic susceptibility also
reflects changes in the depositional regime (e.g. pelagic to terrigenous), but diage-
netic formation of minerals like greigite will produce high values too. Comparing