Published online by Cambridge University Press: 01 May 2009
During an investigation of the ‘Yellow Sands’ and Magnesian Limestone of Durham and Northumberland, several lenticular and irregular hollows or caverns, containing ‘Yellow Sands’ and light yellow marl, were noticed in the Lower Brecciated Magnesian Limestone at Trow Rocks, about one mile south of the Tyne (see Map, Fig. 1).
page 299 note 3 The classification of the Permian adopted in this paper is as follows:—
7. Upper (Concretionary) Magnesian Limestone.
6. Upper Middle Magnesian Limestone.
5. Brecciated Magnesian Limestone of irregular thickness.
4. Disturbed beds of Lower Limestone.
3. Undisturbed Beds of Lower Limestone.
2. Marl Slate.
1. Yellow Sands.
The ‘Yellow Sands’ lie unconformably on the Coal-measures.
page 302 note 1 The effects of the horizontal thrust on the Permian of this area have been fully described by Dr. Woolacott in Memoir No. 1, Durham University Philosophical Society. For our purposes it is sufficient to state that considerable horizontal movement of the upper beds of limestone has taken place over the lower, causing brecciation of the lower and middle Magnesian Limestone; part of the lower limestone lying under the thrust-plane is slightly disturbed, but remains unbrecciated.
page 303 note 1 Q.T.G.S., ser. II, vol. iii, pl. vi, fig. 1, 1835.Google Scholar
page 304 note 1 Professor Lebour, , Trans. N. of England Inst. Min. Eng., vol. xxiv, p. 370, 1902–1903.Google Scholar
page 305 note 1 Dr. Woolacott, “A case of Thrust and Crush-brecciation in the Magnesian Limestone of County Durham”: Univ. Durham Phil. Soc, Memoir No. 1.