Manganoxyd-Phasen als Pigmente antiker Vasenmalerei
function (dots) and the fitted survivor function (continuous line) for ear thquakes with M ~ 2.0 in Eastern Canada for the period t925-1965 (Ranalli, in preparation). Seismic zoning in terms of frequency isolines of damaging earthquakes is therefore a useful first step in ear thquake risk analysis. In order to refine the ear thquake risk index ~ however, it is necessary to weigh it for magnitude, focal depth, and ground response. Ultimately, an empirically based relation between ground acceleration, distance, and magni tude is required, so tha t ear thquake risk can be translated into terms of more immediate relevance to h u m a n and social problems.
Four shades of black: Non-invasive scientific studies on the painted potteries from Shahr-i Sokhta, eastern Iran
Abstract Shahr-i Sokhta in east of Iran represents different stages of settlements from the fourth to the second millennium BC. A large assemblage of ceramics shards has been unearthed from Shahr-i Sokhta many of which are decorated with different shades of black, yellow and red colours. Micro X-ray fluorescence (μ-XRF) and micro-Raman spectroscopy (μ-Raman) on some seventy painted shards from Shahr-i Sokhta with polychrome, bi-chrome and monochrome decorations showed haematite and goethite as red and yellow decorations, respectively. Black decorations, however, consisted of four main groups including carbon black, magnetite, haematite and jacobsite. This paper represents a successful application of non-invasive spectroscopic methods for identifying pigments on archaeological ceramics.
The Technique of Attic Vase-Painting
from a variety of viewpoints for several centuries. In their historical order the following is a list of the principal areas of investigation: (i) Interpretation of paintings on vases; (2) Chronology of vases; (3) Style of painting; (4) Style of pottery; (5) Technical analysis. The techniques used to produce Attic pottery have long intrigued scholars, but only in the past two decades has important progress been made in analyzing and reproducing them.' The turning point in the technical study was the reproduction of the ancient black glaze in 1942 by Dr. Theodor Schumann who used a peptized clay slip as the glaze matter and subjected his pottery to oxidizing, reducing, and reoxidizing firing conditions. It appeared to me that there was considerable need for further study in the technique of Attic vase-painting. First, in the field of the accessory colors. These had been observed by many scholars but had not been properly reproduced. An exception is the intentional red glaze reproduced by Marie Farnsworth and Harriet Wisely.2 Second, in the discovery of the means by which the Greek painters applied their black glaze and accessory colors to the vases, including the proper sequence. Third, in the reproduction of the technique of making the celebrated Attic relief line, which, though noted, had never been successfully reproduced. Technical data on Greek clays, ancient or modern, are not very comprehensive. Therefore a series of spectrographic analyses was made.' Table I compares the composition of the clay body and the black glaze of a fragment of a foot from a fifth century B.c. vase found on the outskirts of the Agora in Athens. This comparison shows that the composition of the clay body and the black glaze are basically the same with a higher concentration of the heavier minerals in the glaze. An important point is the fact that there is no element found in substantial quantity in the black glaze which is not also found in the clay body. This bears out the findings of Dr. Schumann and other researchers that the color of the black glaze is not created by the addition of a special ingredient or pigment. In order to reproduce an ancient Greek black