434 I'HE LANDSLIP AT CLAXHEUGH. 



The Landslip at Claxheugh, Co. Durham, September, IQO^. 



By David Woolacott, D.Sc, F.G.S. 



On the 15th of September, 1905, a landslip occurred at 

 Claxheugh, which is an escarpment of Permian rocks situated 

 by the side of the river Wear, about two miles to the west of 

 Sunderland. An explanation of the interesting and peculiar 

 section exposed there, was given by the present writer in a 

 former volume of the Transactions of the Natural History 

 Society of Northumberland, Durham, and Newcastle-upon- 

 Tyne (vol. xiv., pt. ii., 1903), and as the causes of the landslip 

 are primarily due to certain phenomena described in that 

 paper, it seems proper that a short description of it should 

 appear in these Transactions. 



The section at Claxheugh is about 100 feet high, and is 

 built up of four distinct layers of rock. Its base is composed 

 of the soft, incoherent, and easily-weathered Yellow Sands, 

 of which about 60 feet are exposed, and which has been 

 denuded both by man and natural eroding forces, the upper 

 strata having been thus continuously undermined. At the 

 western end of the section the Marl Slate rests on the Yellow 

 Sands, and it is in turn overlaid by the regularly-bedded 

 Magnesian Limestone (Lower Magnesian Limestone of 

 Howse). The whole of the upper part of the section con- 

 sists of a hard, durable, compact, crystalline, unbedded and 

 fossiliferous limestone, which is the lower division of the 

 Middle Magnesian Limestone of Howse. It formed — until 

 the landslip occurred — a bold, jutting-out crag along the 

 entire length of the upper portion of Claxheugh. 



The peculiarity of the section was that the two middle 

 layers — the Marl Slate and the regularly-bedded Magnesian 

 Limestone — did not extend along the whole of the escarp- 

 ment, being absent from the eastern end under rather peculiar 



