ARCHAEOINTENSITY STUDIES OF PERUVIAN POTTERY - FROM 1200-BC TO 1800-AD

Archaeointensities were determined by the Thellier method from about 6 0 ceramic samples from Peru, with ages ranging from 1200 B.C. to 1800 A.D. The stability of NRM was analyzed for each sample using stepwise thermal demagnetisation. Partial TRM (PTRM) checks were used to detect any chemical change due to the laboratory heating. Anisotropy of both magnetic susceptibility and TRM were measured but found to be very sm all. The mineral magnetic properties of the samples were investigated using several techniques, including Curie temperatures, susceptibility variations from low temperature (about -200-degrees) to room temperat ure, and hysteresis measurements, and the results were used to estimat e magnetic mineralogy and successfully select samples suitable for arc haeointensity measurements. Finally a secular variation curve covering the past 3000 years was obtained for Peru.