# Autochthonous or Allochthonous, the Prehistoric Pottery of Cueva de Los Postes
## 3 Results
### Pottery  
FTIR spectroscopic analysis allows us to identify the raw material of the sample as being from the kaolinite-serpentine group. This conclusion is based on the observation of the spectra, which in the case of the outer portion POST-1E show a typical peak of aluminum silicates discriminating for the kaolinite clay type at 989 cm\({}^{-1}\). The water peak typical of serpentine appears at 3370 cm\({}^{-1}\). In the POST-1I inner surface, the same ceramic type is identified with a typical peak at 982 cm\({}^{-1}\) and a water peak at 3360 cm\({}^{-1}\). The inner surface also reveals the presence of organic substances (peaks at 2924 and 2853 cm\({}^{-1}\)) that could be due to the use of the pottery vessels or to post depositional actions due to the environment of the Cueva de Los Postes. The composition of POST-2E fits into the kaolinite-serpentine group. It shows the typical peak of the kaolinite clays type mineralogical group at 978 cm\({}^{-1}\) and the water peak at 3400 cm\({}^{-1}\). In contrast, the inner surface POST-2I is identified as meta-kaolinite because it has the typical kaolinite ceramic type peak at 988 cm\({}^{-1}\) and two of the three peaks of water (at 3530 and 3396 cm\({}^{-1}\)) that identify kaolinite, leading to the sample's identification as meta-kaolinite. POST-3E and POST-3I  
This sample presents itself as kaolinite on both the outer and inner surfaces. In fact, on both surfaces it presents the three peaks typical of kaolinite waters, together with the peak typical of the aluminum silicates of kaolinite type clays. Specifically, POST-3E presents the peaks of the aluminum silicates at 999 and 916 cm\({}^{-1}\) and those of the kaolinite waters at 3694, 3618, and 3384 cm\({}^{-1}\). POST-3I, on the other hand, has the typical kaolinite aluminum silicates peak at 994 cm\({}^{-1}\) and the typical kaolinite group water peaks at 3695, 3619, and 3400 cm\({}^{-1}\). Figure 4: Comparison of the different spectra of the external parts of the samples, taking into consideration the characteristic peaks (Edited by [PERSON]). Figure 5: Comparison of the different spectra of the internal parts of the samples, taking into consideration the characteristic peaks (Edited by [PERSON]). POST-4E and POST-4I  
The analysis of this sample leads to the identification of kaolinite for the outer surface and serpentine for the inner surface. The outer surface, POST-4E, has typical aluminum silicates peaks at 999 and 914 cm\({}^{-1}\) and water peaks at 3694, 3619, and 3364 cm\({}^{-1}\). This surface also has organic residues identified by the presence of a peak at 2929 cm\({}^{-1}\). POST-4I, on the other hand, is serpentine because it has the aluminum silicates peak typical of the kaolinite type clay group at 984 cm\({}^{-1}\) and the serpentine water peak at 3368 cm\({}^{-1}\). POST-5E and POST-5I  
The observation of the FTIR spectra of the POST5 sample highlights the meta-kaolinite composition of the external part and kaolinite-serpentine group for the interior. In this respect, the typical peaks of kaolinite aluminum silicates at 988 cm\({}^{-1}\) and of two of the  
Figure 6: FTIR spectra of the six sediment samples (Edited by [PERSON]). three typical kaolinite waters at 3600 and 3386 cm\({}^{-1}\) (which lead to it being identified as meta-kaolinite and not kaolinite) are evident on the outer surface of POST-5E. POST-5I, on the other hand, has a typical peak for aluminum silicates at 987 cm\({}^{-1}\) and a typical peak for serpentine clay waters at 3399 cm\({}^{-1}\). POST-6E and POST-6I  
This pottery fragment is composed of meta-kaolinite on both surfaces. The aluminum silicates component peaks are at 984 cm\({}^{-1}\) in POST-6E and 983 cm\({}^{-1}\) in POST-6I, while the typical water peaks are 3616 and 3385 cm\({}^{-1}\) on the outer surface and 3616 and 3384 cm\({}^{-1}\) on the inner surface. In this sample, the outer surface shows the presence of organic substances identified in peaks 2925 and 2851 cm\({}^{-1}\).