131 
THE MEDITERRANEAN NATURALIST 
Spratt, Dr. Adams, Von Th Fuchs, and other geo- 
logists considered it as such, and it was not until 
the results of the investigations of Dr. John 
Murray were made known, that the real signifi- 
cance of the misnomer was apparent. 
From the analyses made by Dr. Murray it was 
shown that there was but 12.88 per cent of inso- 
luble matter in the samples that he analysed, and 
that, that residue was made up of silica, ferric 
oxide, alumina and a small quantity of lime. On 
the other hand, there was found to be as much 
as 80.24 per cent of carbonate of lime. (1) 
Sections of the rock were made, and were 
examined under the microscope, and it was shown, 
that the carbonate of lime consisted of the shells 
of foraminifera, the greater number of which 
were GLobigerina. 
The name of the deposit was therefore changed 
to one that more accurately described the charac- 
teristics of the formation, and instead of “Sand- 
stone”, it is now known as the “ Gl-obigerina 
Limestone 
The formation extends throughout both islands; 
but in the north western and western parts the 
deposits, that overlie it, entirely mask it from 
view. In these localities, the only means of access 
to it, are those afforded by the outcrops along the 
hill sides, the faces of the faults, and the sides of 
the valleys. 
But in the East, and South. East of Malta, and 
in the South West of Gozo, a very different state 
of things prevails. 
In so thorough a manner have the upper depo- 
sits, there, been denuded down, that not a vestige 
of them remains in an area, that may be taken as 
representing at least two thirds of the extent of 
the two islands. Over this area, the Globigerina 
Limestone forms, with few exceptions, the surface 
deposit. 
In several localities, there are isolated patches, 
where the eroding agents have laid bare the 
underlying Coralline Limestone; but so insigni- 
ficant are they in size, that their aggregated areas 
would not amount to one twentieth of the total 
area of the islands. It is principally in the western 
half of Malta, that they are to be found; thus at 
(1) “ The Maltese Islands with special reference 
their Geological structure” Dr, J* Murray 1889. 
the north-eastern extremity of the Great Fault, 
and proceeding in the direction of the line ox the 
Fault to within a short distance of Ta Binjcmma, 
some excellent sections are exposed to view. 
A limited area around Musta, Zebbug, the 
Lunatic Asylum, the shores of St. George’s and 
St. Julian’s Bay, from the shooting range at Rica- 
soli to Zoncar Tower, the shores of Marsa Scala, 
and the whole of the cliffs extending from Marsa 
Sirocco in a north-westerly direction to Fommer 
Rih, will afford good oppportunities for studying 
the nature of the work, that was effected when 
the Globigerina deposits were swept from these 
areas. 
In Gozo, the work of denudation has not been 
so extensive; and the Globigerina bed, even where 
exposed at the surface, preserves a uniform 
thickness throughout. The only remarkable ex- 
ceptions to this, are found in the gorges of Migiar 
Scini, Cala Sclendi and Gala Duera, in each of 
which the Lower Limestone has been laid bare* 
The distribution of the formation as a surface de- 
posit, is more complicated in Gozo than in Malta. 
The Globigerina beds of Gozo, lie exposed over 
an area equal in extent to about one fifth of that 
in which it is found to occur in Malta. 
The stone of the formation varies too consider- 
ably in colour and quality. 
The .late Admiral Spratt, considered that the 
formation was made up of at least, five varieties of 
rock. But this is, a question, upon which there is 
some difference of opinion, as the kinds of rock, 
of which the bed is composed, are very various in 
their character, and appearance and in the posi- 
tions of the horizons that they occupy in different 
parts of the formation. All of the different varie- 
ties are fine-grained, and are of a porous texture. 
They are, therefore, easily tooled; and are much, 
used for building purposes. The prevailing c our 
of the rock is a whitish grey, son 
retimes inc 
Im- 
ing to a yellow, and then passing 
into a rede 
lisk 
or orange brown. Situated at abo 
n t fhp mi, 
U.U C-LLC 111 - L 
Idle 
of the formation, there is a dark-bl 
ue rock, wl 
rich 
persistently occupies the same re 
alive posit 
don 
throughout the bed. It is of 
rn exceed!. 
perishable nature, and is, therefore, 
Out lime l 
ised 
for economic purposes. At Slier 
rp • v 
na, iigne 
and 
at Marsa Sirocco sections of it 
, exhibitin 
g a 
considerable thickness, are to be 
m ail along 
the 
