Table 1 Description and interpretation of background lithotypes with photo of original core section (origin of line scan is indicated in the lower right corner of core photos, scale is in cm)

LB1: light to dark grey, partly black, mostly finely laminated (< 1 mm) to laminated (< 5 mm) silty mud. Sporadic cm-scale black and slightly coarser layers with a brighter top. Increased bSi- (up to 7%) and organic matter-content (up to 3%), and variable CaCO₃-content (~ 30–50%)

Finely laminated varves, thickness changes due to variable runoff. Allochthonous origin of carbonates dominates over the insitu chemical/biological induced production. Black colour and higher organic matter- and bSi-concentrations are linked with eutrophication and iron-sulphide formation. Deposited in deep water, low-energy, and reducing conditions

LB2: light to dark grey, mostly laminated (< 5 mm) to finely laminated (< 1 mm) silty mud. Few cm-scale dark and slightly coarser layers with a brighter top. Very low bSi- (< 1%) and organic matter-content (~ 1%), and CaCO₃-content ~ 20–30%

Finely laminated varves, thickness changes due to variable runoff. Allochthonous origin of carbonates dominates strongly over the insitu chemical/biological induced production. Deposited in deep water and low-energy conditions

LB3: light to dark grey mottled clayey silt. Some scattered laminae. Dots and smears may indicate original layering

Disturbed sediments; drilling artefact. Mainly top and bottom parts of the core sections are affected

LB4: mainly finely laminated to partly layered grey to beige-grey silty mud. Very low bSi- (< 1%) and organic matter-content (~ 1%). CaCO₃-content of ~ 25–30%

Finely laminated varves, thickness changes due to variable runoff. The increased concentration of allochthonous carbonates indicates rapid clastic deposition that may be correlated to increased sediment flux. Deposited in deep water and stable low-energy conditions

LB5: mainly finely laminated to partly layered grey to beige silty mud. Very low bSi- (< 1%) and organic matter-content (~ 1%). CaCO₃-content ~ 45–50%

Finely laminated varves, thickness changes due to variable runoff. Carbonates are mainly product of bio-chemical-induced precipitation. Deposited in deep water and stable low-energy conditions

LB6: mostly homogeneous, partly laminated beige to grey-beige silty mud. Very low bSi- (< 1%) and organic matter-content (< 1%). CaCO₃-content ~ 25–30%

Dominated by clastic sedimentation. The more homogeneous parts were deposited in stable and rather low-energy conditions, with low sedimentation rate. The more heterogeneous parts were deposited in more unsteady energy conditions with a more variable sedimentation rate

LB7: mainly finely laminated to partly layered alternating grey-beige and yellowish-beige clay. No traceable bSi- and organic matter content. Average CaCO₃-content ~ 30%

Background sediment deposited during the inactive phases of the subaquatic channel. The varves are interpreted as alteration of aeolian transported loess deposits and clastic sedimentation. Thickness changes due to variable runoff. Deposited in deep water and stable low energy conditions (Niessen et al., 1992; Wessels, 1995, 1998a, 1998b, 1998c)