56. On the so-called Midford Sands.
By Prof. J. Buckman, F.G.S., F.L.S. (Read June 25, 1879.)
At the village of Midford, some three miles to the south of Bath, is a fine section of the upper beds of the Inferior Oolite rock, consisting of a cap of oolitic freestones of some 20 feet in thickness, resting upon a mass of sand, of which 25 feet are exposed at the station, and which presents all the features of the sand at Bradford Abbas and Bridport Harbour, as the sands are loose, vary in colour, and present occasional bands of hard compact stone.
From these sands being so well shown at this place, Prof. Phillips was induced to name them, after the village, the "Midford Sands;" and he thus writes upon the section:—
"If we wish to draw a hard limit of mineral deposits, it should probably be between the sand and its calcareous cover (which is often absent); but if we desire to study organic sequence, we shall unite the sands and their shelly cap into a transition group"[1].
Now as this "shelly cap" is the one so highly charged with Cephalopoda we further quote the following:—
"The 'Cephalopoda-bed;' as Dr. "Wright proposes to call the cap limestone of this sandy series, exists where the shells to which it owes its name were specially abundant, or by some natural circumstances were brought together. It is not known in the valleys of the Cherwell or Evenlode, and very partially in any of the branches of the Windrush, Coln, or Churn; but on the western front of the Cotswold cliffs it extends from Cleeve-cloud to Wotton-under-Edge, appears on the Dorsetshire coast near Bridport, and is recognized in France"[2].
Mr. Woodward, in his 'Geology of England and Wales,' adopts the name given by Professor Phillips, as follows:—
"Midford is a little hamlet about three miles south of Bath, and it was there that William Smith first studied the Sands, and called them the 'Sand of the Inferior Oolite.'
"They are very well developed at Nailsworth and Frocester, and the names of these places have been locally used to designate the Sands.
"They consist of micaceous yellow sands, with occasional beds of concretionary sandstone or sandy limestone called 'sand bats' or 'sand burrs,' which sometimes contain organic remains; and they are capped by a brown marly iron-shot limestone, one to three feet in thickness, which yields numerous species of Ammonites, Belemnites, and Nautili, whence this bed has been termed by Dr. Wright the 'Cephalopoda-bed'[3], while the series has been termed the 'Ammonite-sands' by Mr. Hull "[4].
Now it is the object of this paper to show that Prof. Phillips has
