BRINE-SPRINGS AND SALIFEROUS MARLS. 255 
age, named by Sir Charles Lyell, must have been nearly, if not 
quite, of the same period as the marls). 
It is probable that at the close of the Bunter period in Britain a 
marked elevation took place, raising the Triassic formation above 
the ocean, this explaining the entire absence of the Middle Trias 
or Muschelkalk series *. 
In the Keuper age this area was again submerged, a sedimentary 
deposit being formed which is now the Lower Keuper. It was 
probably in a series of inland lakes, or lagoons separated by barriers 
from the sea, that the saliferous red marls and rock-salts were 
formed. The red Keuper deposits were perhaps detritus from older 
gneiss and mica-schists f carried down by rivers containing salts. 
The salts spread in a sediment with the detritus in the lake-bottom 
from which the waters evaporated ; subsequent changes might easily 
account for the solid formation of rock-salts, the nature of the 
waters explaining the curious absence of organic remains in the 
saliferous marls. ‘The Droitwich brine-springs being of even greater 
strength than the waters of the Dead Sea, indicate some similar 
conditions as to their origin, the Great Salt Lake of America giving 
even a better example of what was the origin of the Keuper 
lakes, 
Deposits of salt occur in other formations, such as Magnesian 
Limestones and the blue clays of Sicily, but I cannot think that 
there is a general cause accounting for their occurrence. Certainly 
in some of the continental beds the origin has more likely been 
from hot springs. With regard to the red Keuper saliferous marls 
being for the most part unfossiliferous, an observation of Sir Charles 
Lyell’s is of interest ~, that no stratified rocks containing a very 
large amount of oxide of iron have many fossil remains ; when we 
find fossils it is more in the grey or calcareous bands. Possibly the 
oxide of iron becomes an agent of destruction as it permeates the 
deposits. An instance bearing on the point came under my own 
observation in the Greensands of the Isle of Wight. In the Atherfield 
brown clays and grey cracker-rocks the Mollusca are beautifully 
preserved: atthe base of the Shanklin sands, which are strongly im- 
pregnated with oxide of iron, most of the Atherfield Mollusca occur ; 
but casts only remain, no traces of a shell ever being found ; and even 
the casts crumble away immediately they are exposed to the atmo- 
sphere. So in the Keuper age, if crustaceans, mollusks, or any 
organic structure could exist in the waters of the saliferous marls, they | 
would probably be destroyed by the oxide of iron; any remains left 
would in all probability be from grey bands or gypsum ; in fact I 
believe certain Foraminifera have been discovered in the eypsumy 
though not in the neighbourhood of Droitwich. 
There is one more remarkable point which calls for mention in ‘6 
stratification of the red saliferous marls. Marked lines are visible 
in exposed sections, showing the many subdivisions and different- 
coloured bands. The red marl bands mostly show signs of some 
* Hull, memoir before referred to, p. 106. 
+ Sir C. Lyell, ‘ Elements of Geol.’ p. 362. { Elements of Geol. p. 363. 
