Editing Millstone Grit of Almscliff Crag and Harlow Car, near Harrogate - an excursion

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In the middle distance, a broad vale occupied partly by the River Wharfe is underlain by softer mudstones and siltstones dipping gently southwards beneath the beds in the main escarpment. Lenticular sandstones form low ridges at Dunkeswick and Huby. Round to the west, the north side of Wharfedale is underlain by a series of gentle southerly-shelving dip slopes in the lowest of the Millstone Grits. These beds crop out also in the rising ground to the north. An intervening slack is underlain by softer beds (these can be seen later at Harlow Car).
 
In the middle distance, a broad vale occupied partly by the River Wharfe is underlain by softer mudstones and siltstones dipping gently southwards beneath the beds in the main escarpment. Lenticular sandstones form low ridges at Dunkeswick and Huby. Round to the west, the north side of Wharfedale is underlain by a series of gentle southerly-shelving dip slopes in the lowest of the Millstone Grits. These beds crop out also in the rising ground to the north. An intervening slack is underlain by softer beds (these can be seen later at Harlow Car).
  
Near at hand, to the east and south, the Almscliff Grit forms a continuous grassy ridge with a well-marked 7–10° dip slope slanting down under the mudstones of the middle distance. This dip slope is the one that runs down from the crag to Cliff House; North Rigton is also built on it. The crag is clearly an anomalous feature, a local rocky projection from what elsewhere is a smooth grassy ridge. It is also clear that there is a 90° difference in dip direction between the sandstones in the crag (dip to northeast) and the main dip slope (dip to southeast). The disparity is attributed to syndepositional slump-faulting, caused by instability in the underlying pile of rapidly deposited sediment. The mass of slumped sandstone (the crag itself) is dipping back towards the slump scar, and the fault runs round the north and northeast sides of the crag. The geometry of the feature is the same as that in a rotational landslip. The Almscliff slump moved while sand was being transported across the area, so although the landslip topography was evened out, more sediment was preserved in the slump scar than elsewhere. The general southeastward dip was imposed much later, at the end of Carboniferous times, when Variscan earth movements caused widespread folding.
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Near at hand, to the east and south, the Almscliff Grit forms a continuous grassy ridge with a well-marked 7-l0° dip slope slanting down under the mudstones of the middle distance. This dip slope is the one that runs down from the crag to Cliff House; North Rigton is also built on it. The crag is clearly an anomalous feature, a local rocky projection from what elsewhere is a smooth grassy ridge. It is also clear that there is a 90° difference in dip direction between the sandstones in the crag (dip to northeast) and the main dip slope (dip to southeast). The disparity is attributed to syndepositional slump-faulting, caused by instability in the underlying pile of rapidly deposited sediment. The mass ofslumped sandstone (the crag itself) is dipping back towards the slump scar, and the fault runs round the north and northeast sides of the crag. The geometry of the feature is the same as that in a rotational landslip. The Almscliff slump moved while sand was being transported across the area, so although the landslip topography was evened out, more sediment was preserved in the slump scar than elsewhere. The general southeastward dip was imposed much later, at the end of Carboniferous times, when Variscan earth movements caused widespread folding.
  
 
Walk down the path to the road at Crag Farm and turn left.
 
Walk down the path to the road at Crag Farm and turn left.

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