PROCEEDINGS 



THE GEOLOGICAL SOCIETY OF LONDON, 



Vol. IV. Part II. 1843—1844. No. 97- 



Nov. 1, 1843. — " On the Geology of the Maltese Islands." By 

 Lieut. Thomas Spratt, R.N., of H.M. surveying vessel Beacon, F.G.S. 



The axis of the chain of the Maltese Islands runs from south-east 

 to north-west, and is about twenty-nine miles long. Malta, the 

 southernmost of the group, is neEirly seventeen miles long ; and its 

 greatest breadth, measured transversely to the axis, is nearly nine 

 miles. Gozo, the northernmost island, is nearly nine miles long, 

 and its greatest transverse breadth is a little more than five miles. 



The mineral deposits of which these islands consist, are all stra- 

 tified, and disposed in parallel layers. They seldom deviate much 

 from the horizontal position ; but the prevailing dip, which is very 

 gentle, varies from north-east to east by north ; and consequently 

 the prevailing strike of the deposits coincides nearly in direction with 

 the axis of the chain. 



None of the deposits axe wholly devoid of organic remains ; and 

 some of the softer strata contain them in great abundance and in a 

 state of excellent preservation. Many of these fossils are charac- 

 teristic of certain strata, and all are of marine origin. 



Of the strata of these islands the author forms four groups, which, 

 taken in their descending order, are the following : — 



1 . Coral limestone. 



2. Yellow sandstone and blue clay. 



3. Freestone. 



4. Semi- crystalline limestone- 



No. 1. 



The " Coral Limestone"' (A) consists of a reddish-brown or 

 whitish calcareous rock, whic'h is mostly of a compact, hard, and al- 

 most flinty texture. It contains cretaceous nodules, and is sometimes 

 interstratified with soft calcareous sandstone. Its organic remains 

 are particularly abundant in the cliffs abutting on the different bays 

 on the north-west coast of the island of Malta. In the cliff at the 

 west end of the Gianhina Valley, on the south-west coast of the 

 island, the coral limestone is nearly 100 feet thick ; but on the dif- 

 ferent hills which, in other parts of the island of Malta and in Gozo, 

 are capped by this deposit, it now presents a thickness only of from 

 twenty to sixty feet. Near Casal Garbo, towards the north-western 

 angle of Gozo, the only remains of the coral limestone which origi- 

 ginally formed a continuous upper crust over that part of the island, 

 are detached masses of this deposit, lying on the surface of denuded 



VOL, IV. PART II. s 2 



