372 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 9,
valley, at the borders the Upper Lias, over the main-flat the Middle
Lias, and in a narrow central band the Lower Lias, are in succession
the surface-beds,) is a pit in the division D. The section here
is about 30 feet in elevation, and consists entirely of white sand and
sandstone, in which no fossils have been found. Some of the lower
beds of this section are seen in the low side-section to pass into
slightly ferruginous sandstone, some fractured surfaces of which,
when held in one direction towards the light, present a peculiar
lustre, proceeding from innumerable minute facets of crystals of
carbonate of lime.
To return to the neighbourhood of Hopping Hill — upon the Dallington side of the valley and brook already referred to, is an old stone-pit at x, which presents a section of about 25 feet elevation, consisting entirely of compact brown sandstone, in seven or eight beds, yielding no fossils — precisely the material of the white sandstone of w, plus the ferruginous colouring.
Again, at y, three-quarters of a mile S.E. of Hopping Hill, is a recently opened pit, just showing at one extremity the White Sand C, and beneath this the following section : —
Section of Pit on the Dallington and Duston Road.
ft.
1. Coarse sand (decomposed sandstone?) 1
2. Very broken sandstone 6
3. Flaggy sandstone, slightly calcareous 4
4. Sandstone in beds of from a few inches to two feet thickness 7 to 8
All brown from ferruginous colouring — no fossils.
At a few yards from this spot, and at nearly the same surface-level, two wells have been sunk through 68 feet, by admeasurement, of ferruginous rock, without dipping into the Upper Lias. In these wells, at some depth below the base of the above pit, the Astarte-elegans zone was penetrated.
I have obtained from the well-sinker the following rough statement of the section of these wells : —
Section of Wells at Duston.
About ft.
1. Red " rammell" and sand 14
2. Red Rock, in various beds 14 [From some materials which I obtained when the well was sunk, I assume that the zones of limestone and slate occur in these beds.]
3. Red Rock, in three courses, very full of fossils 7 [The Astarte zone, of which I obtained a large block, occurs in one of these courses.]
4. Red "Freestone" 14
5. Ironstone 8
6. Green Rock [" like the lower beds of Duston Ironstone"] 8
The Green Rock was not bottomed, plenty of water being obtainable, but forms the flooring of the well.
The above thicknesses were only estimated by the well-sinker,
