## 4 Discussion
### Paleoceanographic Application  
In seawater, Fe and Ti are trace elements, with Ti being highly conservative due to the almost absent use in biological process; in contrast, Fe is a very important micronutrient that can limit primary productivity [27]. In the sediments, these elements have a similar behavior being present mostly in the form of amorphous or poorly crystalline (hydro)oxides (TiO\({}_{2}\) and Fe\({}_{2}\)O\({}_{3}\)). Moreover, Fe is a major component of many clay minerals derived from soils [28], while Ti weathering rate is very slow and it is considered immobile [29] also if some studies considered it is mobile in soils [30]. Once these elements and minerals are buried, they can suffer reduction or authigenic mobilization/precipitation [31,32]. However, this is more common in organic-rich deposits. For sediments in which terrigenous materials are dominant, the authigenic components are negligible if compared with their fairly high contents in terrestrial detritus [31]. Ca is a major element essential to many organisms in the seawater, since several organisms use it to build their skeletons. Therefore, its content in the sediments reflects directly the biogenic part of the sediment, being represented in the sediments primarily as Calcium Carbonate Content (CaCO\({}_{3}\)) in the form of calcite or aragonite. Fe and Ti are elements mainly associated with the terrigenous fraction of the sediment, related to the siliciclastic components of the sediment [1]; in turn, Ca is primarily a component of the marine fraction of the sediment, associated mainly with variations in the carbonate content. Therefore, both of these elemental ratios reflect the relation between the terrigenous input and the marine contribution, and by conclusion do not allow many reliable reconstructions of terrestrial climate conditions, in particular for past climate changes [7]. According to this, the variations of the lnTi/Ca and lnFe/Ca in our record are associated with the oscillation between the marine and terrigenous fraction deposited, with the major terrigenous contributions being observed during the MIS 5b and the MIS 4 (Figure 3). However, elementary ratios using Ca must be looked at carefully, because the dilution and dissolution effects can affect directly Ca concentrations [1,7,19]. Mainly three processes can influence the calcite, as well as Ca, content: the primary production, the dissolution and the dilution made by other types of materials. In the core area, dissolution does not influence the micropaleontological records and the paleoproductivity maxima occur in the same periods of higher terrigenous supply [18]. This leads to the conclusion that the calcite content is controlled mainly by the dilution of the marine fraction by terrigenous input, which can be observed by the mirror distributions in the calcite and quartz content (Figure 6). Therefore, the lnFe/Ca and lnTi/Ca are reliable indicators of the terrigenous sediment input and continental runoff in our study. When comparing calcite mineral trends with the CaCO\({}_{3}\), we observe a similar trend (Figure 6), indicating that calcite is the predominant carbonate phase. Therefore, at least the major component of calcite is presumably from a marine biological source, indicatingthat the pelagic deposition is a great contribution process to the bulk sediment in this area. In turn, the Fine Fraction content (FF), which is the percent of sediments with size lesser than 63 \(\upmu\)m, does not seem correlated to any of these minerals, revealing that the variations of the minerals are not only due to different grain sizes, but are probably due to changes in the bottom hydrodynamics and mobilization of relict materials. Some studies already used the variations of minerals (quartz and calcite) as proxies of the oscillations between terrigenous and marine inputs [11; 12]. So, in addition to the InTi/Ca and InFe/Ca ratios, the content of quartz is also used as an indication of terrigenous materials from the mineralogical perspective.