4,34 Geological Society. 



1 . The oldest formation which he met with is a sandstone with a 

 few subordinate beds of marl and limestone, occupying a great portion 

 of the central chain of the island, and extending along part of the 

 northern coast. Its exact age he was unable during his rapid tour to 

 determine, but it is older than the Jura or Apennine limestone. In 

 travelling along the coast eastward from Palermo, the author first 

 came on this sandstone near the river Pilnto, a few miles to tlie west 

 of Cefalu ; and the island eastward of this point principally consists 

 of the same rock and its accompanying shales. In his route thence to 

 Mistretta he passed over the great chain of the island, which in this 

 part consists entirely of this sandstone, and attains a very great ele- 

 vation. The mountain of Sancta Diana rises 3875 feet above the 

 level of the sea, and is overtopped by many others within sight, on 

 the loftiest of which, the Madonia, patches of snow were still visible 

 on the 8th of June. 



The dip of the sandstone strata is various ; but they are in general 

 highly inclined, and sometimes vertical. Their direction is for the 

 most'part parallel to the general direction of the chain itself, — namely, 

 inclining from the north of east to the south of west. At Mistretta 

 the strata are seen distinctly to dip away from an anticlinal line, 

 whicli passes across the mountain of Sancta Diana, extends between 

 the hill on which the castle stands, and the small hill of S. Catarina 

 on its north, and thence across the valley to the east of Mistretta. 

 At the Monte di Castelli, the highest point near Mistretta, the strata 

 have two different bearings, one nearly east and west, and the other 

 north and south ,: and a similar observation was made at Nicosia. 

 The author directs attentior; to the fact, as indicative of the central 

 chain having been raised during at least two distinct periods of ele- 

 vation. 



2. The formation next in order to the sandstone, and of more recent 

 origin, is the limestone and dolomite composing the north-western 

 part of the island, and which the author considers as the equivalent 

 of the Jura or Apennine limestone. It rises in bold, precipitous cliffs 

 flanking the bay of Palermo, and at the distance of about two miles 

 inland bounds the rich plain which lies along the coast. The dolomite 

 closelv resembles that of the Tyrol, presenting a bold, rugged outline, 

 without a trace of stratification, and having its naked sides traversed by 

 numerous rents and fissures. Caves, sometimes containing bones, are 

 frequent, formed probably by the enlargement of fissures by the action 

 of water. The limestone, which frequently contains magnesia, is 

 stratified, and the strata are often highly inclined. 



3. The third formation distinguished by the author consists of marls 

 and limestones containing Nummulites and Hippurites, and which he 

 believes to belong to the chalk and green-sand formations of other 

 parts of Europe. These beds are horizontal, and lie on trap-tufa and 

 basalt. They were observed at the most southern extremity of Sicily: 

 they extend from the village of Pachino to the sea — occupy the upper 

 part of the island of Cape Passero — and form the base of the small 

 island named the isola delle Correnti. 



4. The next rocks in the series are cretaceous limestones and marls 



of 



