## 2 Materials and Methods
### XRD and XRF Analysis  
[PERSON] et al. [18], at the Laboratory of Marine Inorganic Chemistry (LAQIMAR--IOUSP), originally analyzed the same samples, using a Varian Inductively Coupled Plasma-Optical Emission Spectrometry, model VISTA-MPX. Therefore, the samples were re-analyzed to determine if BTX II Benchtop XRF measurements ensure precision and consistent measurements. The selected samples were prepared as described below.  
The first step of sample preparation was the weighing of the humid bulk sample. After this, the samples were heat-dried at less than 60 \({}^{\circ}\)C in a laboratory stove and then weighed again to obtain the dry weight. The next step was the wet sieving in a 63 \(\upmu\)m mesh. The fraction >63 \(\upmu\)m was weighted and stored for future foraminififeral analysis. Approximately 1 cm3 of sediment (<63 \(\upmu\)m fraction) per sample was hand-ground in a jade mortar to be used in the XRF analysis. This size fraction was selected due to the smaller interference in the intensity values measured by the Olympus BTX II Benchtop XRD/XRF device (Olympus, Wobum, MA, USA).  
The measurements were performed in the Centro Oceanografico de Registros Estratigraficos (CORE) at the Instituto Oceanografico from Universidade de Sao Paulo. This equipment utilizes a cobalt source to perform XRD/XRF measurements that generate noise in the iron trace reading, causing overestimation. To eliminate noise, a 99% calcium carbonate (Merck, Darmstadt, Germany) sample, with small amounts of iron (concentration < 0.001%), was used and subtracted.  
It is also important to point out that XRF is a semi-quantitative analysis able to support variations in the core depths. Since each element has its peak of intensity in a different quantity of incident energy. It is possible to compare the data of every sample, relating how was the variation of intensity in any sample at every depth of the core.  
To determine the optimal number of expositions, diffractograms were obtained with different exposure times, and the best time/resolution was found at 100 exposures. The average energies utilized for peaks (Ka) intensity measurement were: 3.70 keV for Calcium, 4.49 keV for Titanium, and 6.43 keV for Iron.  
Figure 1: Region studied with the location of the core GL-451, Botuverá cave and the main rivers that contributes to the terrigenous supply, using the software Ocean Data View [20]. Modified from [PERSON] et al. [21], based on [PERSON] et al. [18].  
To analyze the elemental ratios, the intensity data were transformed and presented in the logarithmic form of elementary rates. According to [PERSON] and [PERSON] [8], unlike the analyses that use the elements separately, elementary ratios are not subjected to dilution effects, avoiding the lack of symmetry exhibited by ratios.  
The BTX II applies at the same time the XRD and XRF techniques, therefore, additionally to the elementary analyses, mineralogical data were also obtained. After the measures, semi-quantitative analysis was conducted with the High Score plus version 3.0 software [22], with the goal to identify the minerals present in the samples and then observe the variations of the main mineral constituents along the different studied periods. The data were then presented in percentages of the main mineral constituents.