The stratigraphy and structure of the syncline of stainmore

Abstract

The stainmore area is a typographical and geological depression lying between the two upstanding block areas of the Northern Pennines. The succession includes bede of Yoredale facies of the middle and upper Limestone groups, overlain by “Millstone Grit”, the total time range extending from late P(_2) age, probably to late E(_2). Detailed mapping of marine horizons has enabled the establishment of correlations between the successions of the Alston block to the north and tho Askrigg block to the south, They show that marine conditions were more persistant to the south and east of the stainmore area. Millstone grit facies entorent a lower horizon in the east and west of the stainmore area than it does in tho centre. Tho grite on the flanko correspond to the tenhill grite of N. W. Swaledale and are considered to pass laterally into the coaleleugh transgression bods in the centre. This is demonstrated by equating the upper felltop Limestone of Alston with the Heane Beck Limestone of upper Swaledale. An upper horizon of grit facies is subjacent to Botany Limestone and is considered to be the equivalent of the first Millstone crit of Durham and the water crag Grit of Upper Swaledale, the Botany Limestone corresponding to the shunner pell Limestone. The structure consists of an asymmetrical syncline, pitching gently to the east, with two small elongated domes to the south. The fault pattern on the east is similar to that of Alston block; on the west a semi-radical pattern is apparent. Joint directions are varied. The area has been affected by both the stainmore and Teesdale glaciers, the former being dominant only at first, and showing evidence of a minor readvance and second retreat.