# The Interdisciplinary Approach of Some Middle Bronze Age Pottery from Eastern Romania
## 3 Results and Discussions
### L11 and the Presence of Organic Residues  
The Monteoru fragment (L11) has a higher iron content (5.97%) that suggests using the same ferruginous clay, but also the presence of an appreciable calcium content could indicate a low calcareous clay. The phosphorus concentration of this vessel is 5.23%, most likely determined by the storage of substances with a high phosphorus content. Figure 10: FT-IR spectra of the ceramic fragments from Piatra Neamt–_Lutárie_. The presence of a dark-colored layer identified macro- and microscopically is an indication in this regard. In an attempt to determine the nature of the substance identified inside the vessel, several EDX analyses were performed, both on the outside (L11E), and in particular on the black layer (L11I), including at the interface with the vessel wall (L11I2) to eliminate the possible effects of contamination (Table 2). The compositional results show, in addition to the elements specific to the raw material, the presence of a very high concentration of carbon, which at the interface with the vessel wall is up to 22.9%. This value certainly indicates that this element is organic in nature. Moreover, the carbon appears to have migrated from the inside to the outside, penetrating the vessel wall, which precludes possible contamination. To clarify the SEM-EDX results, an analysis was performed by infrared spectroscopy for the ceramic paste and surfaces (Figure 11). Thus, for the paste of the L11 sample, montmorillonite [51] ((Na,Ca)\({}_{0.33}\)(Al,Mg)\({}_{2}\) (Si4O10)(OH)\({}_{2}\cdot\)nH\({}_{2}\)O) were identified mainly by the presence of the central peak at 3376 cm\({}^{-1}\), from the specific range 3300-3500 cm\({}^{-1}\). In addition, the inner surface spectrum shows the presence of kaolinite [46; 48; 49] at 3562 cm\({}^{-1}\). The presence of the doublets at 915 cm\({}^{-1}\), attributed to OH deformations of kaolinite, is visible up to temperatures of 500 \({}^{\circ}\)C, after which it disappears [46; 50; 51]. It is important to mention that the vessel has a ceramic slip applied on the exterior, which is made of the same type of clay as the vessel. There is also the possibility of an inner slip that was not noticed due to the black layer covering the entire inner surface of the vessel. The intense peaks from 2929 cm\({}^{-1}\) and 2860 cm\({}^{-1}\) are attributed to the organic carbon [47; 50; 55; 59; 60; 61], present on the surfaces but also in the paste, this being the result of the blackish substance identified on the vessel. Metal carboxylates at \(\sim\)1409\({}^{-1}\) and oxalates \(\sim\)1313 cm\({}^{-1}\) may derive from the degradation \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multicolumn{8}{c}{**Elemental Composition in Weight Percent (\%)**} \\ \cline{2-11}  & **Si** & **Al** & **C** & **P** & **Mg** & **Ca** & **K** & **Na** & **Fe** & **Ti** & **O** \\ \hline L11 & 12.14 & 7.95 & 7.07 & 5.23 & 1.14 & 4.13 & 1.68 & 0.80 & 5.97 & 0.49 & 53.40 \\ L11 E & 7.55 & 2.83 & 16.96 & 0.37 & 0.26 & 3.18 & 1.55 & 0.10 & 3.96 & 0.47 & 62.77 \\ L111 & 7.85 & 2.95 & 22.21 & 1.47 & 0.35 & 5.32 & 1.56 & 0.12 & 4.49 & 0.40 & 53.28 \\ L111 & 5.68 & 2.53 & 22.91 & 1.43 & 0.40 & 6.63 & 1.77 & 0.28 & 2.77 & 0.54 & 55.06 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Elemental composition of the Monteoru fragment (L11) for ceramic paste and surfaces. Figure 11: FT-IR spectra for sample L11 (a) ceramic paste; (b) outer surface; (c) inner surface. of some organic compounds. In this regard, it is worth noting that the stretching of C-H contributions appearing in the same spectrum at \(\sim\)2860 cm\({}^{-1}\) and \(\sim\)2929 cm\({}^{-1}\) support the presence of a protein material subjected to degradation processes [62; 63]. The other minerals identified by the uFTIR analysis of the L11 sample are the same as in the case of Costisa samples and will not be repeated.