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is strong evidence to believe that it was covered up by the Lower 
Oolites from the numerous outliers of Robinswood, Bredon and 
other hills which are capped with it. The valley that now 
intervenes was formed long afterwards, and belongs to another 
story of the earth’s history. We are therefore brought near to 
the Silurian and Carboniferous Limestones, and also to the 
Old Red Sandstone. 
Now, in these beds you have the necessary material to form 
the basement series of the Inferior Oolite. The lime may have 
been derived from the Silurian, or Carboniferous Limestones, or 
from both, and the iron from the Old Red. The quartz pebbles 
referred to may have come from a quartz vein from May Hill or 
the Malverns, or from the conglomerate beds of the Old Red in 
the Forest of Dean. That they came with the material which 
formed the Oolitic bed, is clearly shewn by their being embedded 
in it. 
The question I have been discussing is one to which I think 
sufficient attention is not generally given, as it applies to all 
geological formations of a sedimentary origin. With the 
exception of certain rocks, which in part, are chemically formed, 
it should always be borne in mind that all sedimentary rocks are 
made up of pre-existing formations. When we meet with Sili- 
cious sands, they are mostly derived from Sandstone beds—with 
pebbles of various kinds they may be traced to their parent rocks. 
The subject to my mind is full of interest, and is extremely sug- 
gestive, being based upon inductive reasoning, which is the 
ground work of geology, and indeed all other sciences. 
