£02 J. H. Cooke — Globigerina Limestones of Malta. 



colour. It has been formed by bottom currents, and has every 

 appearance of a sand that was at one time filled with shells which 

 have been dissolved away by acidulated water. It is, in fact, what 

 is known as a "rotten sand." 



At page 14 of the report it is stated that spines of Echinus and 

 Spatangus were obtained in No. 6 bore at a depth of 21 to 24 feet, 

 in hard-bound sand. This may have been the same bed as the 

 above. 



The top bed is sandy Boulder-clay and stones, of the great 

 thickness of 43 feet, and I take it to be a ground moraine 1 of the 

 second glaciation. 2 



I have now only to add that when the glacial deposits (drift 

 formation) receive a closer examination than has hitherto been 

 given to them, many more proofs of their marine origin will, 

 I think, be forthcoming. The most accessible exposures are the 

 scaurs of drift along the stream courses, and I seldom return from 

 a day's examination of them without finding additional proofs of 

 the whole drift formation having been deposited in the sea. 



X. — Notes on the Globigerina Limestones of the Maltese 



Islands. 



By John H. Cooke, F.G.S. 



THE Globigerina Limestones of the Maltese Islands consist of 

 a series of beds of varying character, the upper portions of 

 which belong to the Lower Langhian, while the lower are referred 

 to the Upper Aquitanian. The formation extends throughout both 

 islands, but in the north-western and western portions it is masked 

 by overlying beds of clays, greensands, and limestones, of Tortonian 

 and of Helvetian age. 



The Maltese Langhian may be divided, lithologically, into two 

 well-marked sub-series — the upper, which includes the " Marls and 

 Clays," and extends from the base of the Greensands to the top of 

 the Globigerina Limestones ; and the lower portion, which includes 

 the beds A to F of the "Globigerina" series. Palasontologically 

 both divisions agree closely, and contain such characteristic 

 Langhian forms as Aturia aturii and Pecten denudatus. The 

 palasontological analogies of the two groups are shown in the 

 synoptical table of fossils at the end of this paper. The total 

 thickness of the formation ranges from 150 feet to 250 feet. 



Regarded vertically the following tabular summary gives the 

 serial order and the thicknesses of the subdivisions. 



1 From what I have since seen in Ayrshire I have been obliged to abandon the 

 idea that the Boulder-clays are ground moraines pure and simple. I think there 

 is ample proof that they are marine deposits. In places where they have been 

 dragged a bit by the last glacier-ice they become ground moraines. 



2 It is not here argued, of course, that during the period between the two Boulder- 

 clays the country was entirely free from ice. 



