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exploration of a mound on the side of the Common, near 
Bownham House, which, from its appearance, was supposed 
to be a tumulus. 
Before quitting Dudbridge the attention of the Geologists 
was arrested by an unusual appearance in an exposure of 
Middle Lias strata, in a vertical position; the explanation being 
that the Lias had at some period slipped from its position, and 
had caused a fold in the strata. These slips are a common 
feature of Cotteswold valleys, and to such the widening of 
many is largely due. 
Passing over to the opposite side of the valley, under the 
guidance of Mr. Wrircnett, the excavations in the Dudbridge 
brick-pits were examined. This brick clay contains more iron 
than is found in the Upper Lias which overlies it, and produces 
a better kind of brick; while the Marlstone, which runs 
through the section, contains a per centage of iron so consider- 
able as to make it available for smelting purposes were the 
quantity of rock greater. There are two bands of Marlstone 
in the section, separated by six feet of Shale; the upper band 
is about one foot thick, the lower band about three feet. 
Both are fossiliferous, and the Geologists had no difficulty in 
procuring specimens of the characteristic fossils, such as 
Ammonites margaritatus, Unicardium cardioides, Avicula inequi- 
valvis, Cardium truncatum, &. The section is altogether about 
thirty feet deep. 
Leaving Dudbridge, the party proceeded to Rodborough Hill, 
passing in ascending order over the Upper Lias, the Midford 
Sands, and the Cephalopoda beds, stopping at the foot of the 
Common to see the Pisolitic Ragstones, which have thin layers 
of Pisolite in the partings of the beds. The Pisolite of Birdlip 
and Leckhampton Hills is here represented only by these thin 
layers, and disappears entirely a few miles to the south-west. 
The next halt was at a short distance above, in a disused 
quarry, the greater part of which having been sloped down, only a 
small section was exposed, but this section contains the Nerina 
bed in the Oolite Marl, which is the next fossiliferous zone 
above the Pisolite; the intermediate strata consisting of the 
