Remanent magnetism of some modern bricks and a brick kiln-implications for archaeomagnetic work

Abstract

Kilns for making bricks and pottery constitute common remains of ancient activities, and as such they represent valuable objects for archaeological work. Techniques based on the study of remanent magnetism of bricks, pottery and baked soil can provide a means for datation and correlation of these remains. A study of a modern brick kiln is here presented. It is found that these materials are reliable recorders of the direction of ambient Earth's magnetic field at the time of heating-cooling. There are however some potential sources of error, since temperature measurements indicate strong gradients, with places at less than 40°/o the central temperature of the kiln. There, the remanence is a partial-thermoremanent magnetization, and its use·for archaeointensity determinations could lead to errors. The directions of remanent magnetism from all places sampled reproduced within the statistical uncertainties of the technique the observed geomagnetic field direction.