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[1] We report a detailed archeomagnetic and micro-Raman spectroscopy investigation on pre-Columbian pottery fragments from Cuanalan (a formative village in the valley of Teotihuacan, central Mexico). Available radiocarbon ages range from 2320 ± 80 to 2060 ± 90 B.P. Continuous low-field susceptibility versus temperature curves performed in air indicate Ti-poor titanomagnetites as magnetization carriers. Few samples, however, show two ferrimagnetic phases with Curie temperatures compatible with both Ti-poor and Ti-rich titanomagnetites. Hysteresis parameter ratios fall essentially in the pseudosingle-domain region, which may indicate a mixture of multidomain and a significant amount of single-domain grains. Mineralogical composition of the Teotihuacan ceramics has been investigated using micro-Raman spectroscopy. Samples are characterized by highly heterogeneous body matrix mineralogy due to the presence of a large variety of minerals with several mineralogical phases. Observed titanomagnetite and magnetite bands shift toward higher wave numbers, confirming a reducing atmosphere and a relatively high temperature (about 800-900°C) during the ceramic production. This definitively indicates the thermoremanent origin of magnetic magnetization. Archeointensity values have been determined from 7 pottery fragments (47 samples) out of 10 (70 samples) analyzed. Anisotropy of thermoremanent magnetization and the cooling rate effect upon thermoremanent magnetization intensity acquisition have been investigated in all the samples. The mean archeointensity values obtained in this study range from 24.2 ± 3.2 to 40.0 ± 1.7 mT, and corresponding virtual axial dipole moments range from 4.8 ± 0.6 to 8.0 ± 0.4 (10 22 A m 2 ). This corresponds to a mean virtual dipole moment value of 5.9 ± 1.1 Â 10 22 A m 2 , which is lower than the present-day field strength and the predicted values by global models and the latest data compilation. However, our data agree well with currently available absolute intensity values from Mesoamerica. The archeointensity values uncorrected for cooling rate and anisotropy are systematically higher than the corrected values. These uncorrected values agree with the CALS7K model, which may be biased by the fact that such corrections were not applied to most of the previous data.

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The purpose of this paper is to show the benefits and applications of using mid and far infrared reflection spectrometry (IRS) in the analysis of archaeological materials. Infrared spectral databases do not yet exist for rocks and principal minerals. In support of IRS techniques, a catalogue and new spectral database have been created with over 500 infrared reflection spectra in mid and far ranges from more than 250 different archaeological minerals and stone materials. The reflection spectrum serves as a "fingerprint" of all these materials. This new, non-destructive method is useful for spectrometric identification and crystal chemical characterization of many rocks and minerals commonly found in archaeological contexts. Three brief examples of IRS analysis of archaeological materials are presented as test cases. It is suggested that IRS could and should become a routine approach in geoarchaeology and archaeometry for identification and provenance studies. © 2009 Wiley Periodicals, Inc. INTRODUCTIONThe purpose of this paper is to show the benefits and applications of using mid and far infrared reflection spectrometry (IRS) in the analysis of archaeological materials. IRS is a non-destructive technique that can provide diagnostic and crystal chemical information on the mineralogical phases of stone artifacts, artworks, and building materials. Since non-destructive methods are preferred in geoarchaeological and archaeometric identification, the IRS method, which utilizes non-contact light beams, is considered to be an appropriate method for this aim. IRS is also useful as an alternative to the more traditional methods of X-ray analysis such as XRD, SEM/EDS, and EPMA.It is well known that a variety of minerals can occur in stone samples from archaeological contexts. Minerals are also found as pigments and fillers in paint films, in soil molded into earthen artifacts and mud brick, as corrosion products on metal surfaces, in stone fabrications such as sculpture and architectural monuments, in cements, in building stones, and in ceramics. In recent years several papers have been published dealing with IRS analysis of various rocks and minerals, but most of these studies were performed on powdered material (Hawthorne, 1988;Salisbury et al., 1992). To my knowledge, only a few studies have been devoted to the study of principal minerals and gemological materials using in situ non-destructive IRS experiments (Ostrooumov, 1982(Ostrooumov, , 2007Vochmentzev & Ostrooumov, 1987;Martin, Merigoux, & Zecchini, 1989;Banerjee & Gaida, 1999;Ostrooumov, Lasnier, & Lefrant, 1995;Ostrooumov et al., 2004Ostrooumov et al., , 2006, and literature dealing with IRS studies of minerals and stone materials found in archaeological objects is even more uncommon.The current study was undertaken to compensate for the absence of published literature relating to the IRS of mineral and stone artifacts. IRS is a non-destructive method, and thus potentially a very important tool for archaeometrists and geoarchaeologists. Existing infrared spectral...

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