Extract

I. INTRODUCTION.

In this paper the geology of the country of the headwaters of the Washburn is discussed. This river, a tributary of the Wharfe, rises south-west of the village of Greenhow on the high Millstone Grit moorlands between the Wharfe and the Nidd. Here desolate and sparsely populated moorlands extend eastwards from Simon’s Seat (1592 ft.) to Black Gate, the Blubberhouses-Greenhow Road. Included in this moorland area are Catherine or Katty White’s Allotments to the north, a peat-covered wham, ill-drained and of little relief; Pockstones Moor with its striking crags of grit such as Great and Little Pockstones; and, to the south, Rocking Moor, the drainage-divide between the Wharfe and the Washburn.

Grits, sandstones and shales of the Millstone Grit formation outcrop over the area. The lowest beds seen are the Grassington Grits, the basal Millstone Grits, and the highest beds are the Brimham Grits, the approximate equivalent of the Kinderscout Grits. The succession is therefore mainly a sub-Kinderscout succession. It includes towards the top the well-known ‘Shell Bed’ or Cayton Gill Beds.

The district is for the most part covered with peat and drift which has blanketed and obliterated most of the grit features. Fortunately the Washburn and its tributary streams have cut steep-sided valleys into the high plateau and in most of these the rocks are well exposed, though occasionally obscured by valley-slip. The description of the geology is therefore mainly based on work in these valley sections; the outcrops shown across the moorland areas are the ...