| Analysis of 100 parts of Limestone.. | |||||
| By the Ref. J. Holme | By Sir H. Davy. | ||||
| From Denton | From Eldon | From Aycliff | |||
| Carbonate of Lime | 63 | 52. | 48.9 | ||
| ───────── of Magnesia | 34 | 45.2 | 46.6 | ||
| Alumina, Red Oxide of Iron and Bitumes | 2.25 | Iron | 1.1 | 1.56 | |
| Water | .25 | Residuum | 1.7 | 2.8 | |
| ──── | ──── | ──── | |||
| 100. | 100. | 100. | |||
In a quarry at Hartlepool I have noticed a stratum of hard white oolite, the grains composing it being about the size of a mustard seed; but, unlike the Ketton and Riflington roe-stones, it contains no shells or marine exuviæ. I have found at the same place a bed of pale buff coloured limestone of an earthy fracture, punctured with holes not larger than a needle's point. The ornamental parts of the old exchange at Newcastle were carved out of these two varieties of stone.
The four lowest strata of Mr. Goodchild's quarries at Pallion near Sunderland, constitute another variety. Its colour is a dirty light brown; but taking a tolerably good polish it is sold as a marble. In lustre and hardness it resembles a stalagmite; it is met, with at the depth of eleven fathoms from the surface.
In Castle Eden Dean there are cliffs of this rock well worthy of notice; and the perforated rocks at Marsden and Hartlepool, and the caverns at the latter place, at Black-hall near Easington, and on the coast near Monk Wearmouth, deserve the attention of the geologist. These curious and picturesque objects appear to have been formed at no very distant date by the action at the sea, which has dissolved and washed out the soil: marly limestone, with
