THE VOLCANOES AND ROCKS OF PANTELLERIA 
HENRY S. WASHINGTON 
Geophysical Laboratory, Carnegie Institution of Washington 
PART I 
‘ INTRODUCTION 
Since the first half of the last century, when Pantelleria‘ figured 
in the controversy over von Buch’s theory of craters of elevation, 
the geology of the island has been described only by H. Foerstner 
and A. Bergeat. Through Foerstner’s researches the island has 
become classic in the annals of petrography, because of his dis- 
covery there of soda-microcline and the peculiar hornblende, 
cossyrite, as well as of the occurrence of the remarkable group of 
pantellerites. 
In view of the interesting character of its rocks and the rather 
early date of Foerstner’s descriptions and analyses, a re-examina- 
tion of the island was considered to be desirable. Pantelleria was, 
therefore, visited in September, 1905, in the course of a trip to the 
western Mediterranean, undertaken for the Carnegie Institution of 
Washington. 
During my stay I met with the utmost courtesy and hospitality, 
and it is a pleasure to record my thanks to friends on the island, 
among whom may be specially mentioned Captain G. Herrera, 
Captain A. Pocobelli, Lieutenant A. Innorta, and Doctor S. 
Granone. To Professor J. Volney Lewis I am indebted for 
making the photographs of the rock sections. 
GENERAL DESCRIPTION 
The island of Pantelleria lies about midway between Sicily and 
Tunis, rising steeply from depths of over 400 fathoms in the broad, 
deep channel which separates Sicily from Tunis, near the edge of 
the Adventure Bank. It is noteworthy that the volcanic Linosa to 
t Attention may be called to the fact that this is the proper spelling of the name, 
being that used on all the official Italian maps. The chief accent is on the 7, not the 
second e. 
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