sands with shelly oolite interpolated in slabs at Bradford Abbas, Babylon Hill, and the adjacent district.
The following list of fossils from the freestone at Ham Hill and the shelly oolites of Dorset can nearly all be matched in the lower beds of the Inferior Oolite of Gloucestershire.
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Belemnites compressus, Blainv. |
Pecten lens, Sow. |
Now this list of fossils is sufficient to mark the oolitic nature of these thick beds below the Cephalopoda-bed of Dorset; and if this new reading of the matter be correct, our sands are not the equivalents of the Gloucester sands, or rather the Cotteswold sands, but the representatives of the lower beds of the Inferior Oolite, which at Ham Hill is a good freestone, from containing so much lime, while at Bradford it is hard, in bands consisting of a shelly oolite, with thick beds of sand between, not sufficiently indurated to be used as stone.
If this be so, then it is clear that the name of "Upper Lias Sands" cannot be retained for these sand-beds.
The most recently published notion upon the sands is from the pen of Professor Phillips, in which he proposes to name them the "Midford Sands"[1], as they were studied by Smith at the village of Midford, and decided by him to be "sands of the Inferior Oolite." If, however, the sands of the west be really of Inferior-Oolite date, they ought not to be correlated with the sands of the Cotteswolds, as these are in a considerably lower position.
Leaving then this question for further consideration presently, we will now more particularly describe the Cephalopoda-bed of Dorset; and in doing this, it will perhaps be well to first give a section of the oolitic rocks in the middle station at Bradford Abbas, premising that the Ammonite-bed is the most constant in the district.
- ↑ 'Geology of Oxford,' p. 109.
