The ceramics studied originates from the North Peruvian Andes or, more precisely, from the area covering the uppermost parts of the basins of the mountain rivers Alto Chicama, Moche, Chuquicara and Condebamba. A. Krzanowski carried out ar-chaeological investigations in that area in 1973, when the ceramics in question was collected. It comes from 19 sites, most of which (15) are situated in the Alto Chicama basin (designated as AC). The others, i.e. AC-97 and AC-98 lie in the basin of the Chuquicara, Cerro Caupar in the Moche basin and Marca Huamachuco in the Con-debamaba basin (Fig. 1).

Of the abundant ceramic material available, 50 fragments were selected for pe-trographic investigations (Table 1). Moreover, analysis was carried out on a Chimu culture vessel. Though its provenance has not been established, it is known that it has been found in the Alto Chicama region. In view of the difficulties encountered when interpreting the archaeological material from the Alto Chicama, the undisputed origin of the vessel is of great importance since any possible similarities or differences in the technique of manufacture can serve as chronological and culture indicators. The vessel also deserves note for another reason, viz. as a specimen that was damaged and repaired. A hole in the body was pasted up with clay and the vessel was fired again. Microscopic analysis has revealed certain technical details of that reparation.

Investigations were also carried out on the ceramics manufactured today in the village Caulimalca, the only pottery center in the area studied. Ethnographic studies (Krzanowska, Krzanowski 1976) yielded precise data on the technique of manufacture. Microscopic analysis permitted a comparison of this pottery with the archaeo- logical ceramics, using the same criteria and having ascertained the errors and limitations inherent in this method.

The archaeology ceramics was collected, with a few exceptions, from the surface of sites and is, therefore, represented only by fragments of vessels.