Editing Dinantian and Namurian rocks of Bolton Abbey and Trollers Gill - an excursion

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==== Locality 1 [SE 075 541] ====
 
==== Locality 1 [SE 075 541] ====
  
Downstream from the footbridge, across the river, is the best exposure of Upper Bowland Shale (early Namurian, Pendleian Stage) in the district. This large cliff, approximately 20 m high, is maintained by erosion at its base by the meandering River Wharfe. Surface weathering obscures details of the structures present but careful observation of the orientation of thin ribs of muddy limestone indicates that several folds are present. Note the bluish-grey colour typical of slightly calcareous shale, and the orange iron oxide ('''limonite''') stain which results from modern weathering.
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Downstream from the footbridge, across the river, is the best exposure of Upper Bowland Shale (early Namurian, Pendleian Stage) in the district. This large cliff, approximately 20 m high, is maintained by erosion at its base by the meandering River Wharfe. Surface weathering obscures details of the structures present but careful observation of the orientation of thin ribs of muddy limestone indicates that several folds are present. Note the bluish-grey colour typical of slightly calcareous shale, and the orange iron oxide (limonite) stain which results from modern weathering.
  
 
To the right (downstream), the shale is replaced by massive, well-jointed Skipton Moor Grit (Namurian). The contact is clearly a fault, which from this viewpoint appears to be reversed, with the younger grit being thrust beneath the shale. This impression is false; viewed from the footbridge along the strike, the fault is seen to be almost vertical.
 
To the right (downstream), the shale is replaced by massive, well-jointed Skipton Moor Grit (Namurian). The contact is clearly a fault, which from this viewpoint appears to be reversed, with the younger grit being thrust beneath the shale. This impression is false; viewed from the footbridge along the strike, the fault is seen to be almost vertical.
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==== Locality 2 [SE 076 542] ====
 
==== Locality 2 [SE 076 542] ====
  
Take the footbridge across the river, and look right to confirm the orientation of the fault. About 50 m upstream from the bridge, close to the river, there is a good exposure of well-jointed, friable Middle Bowland Shale (basal Pendleian) which '''dips''' downstream (southeast) at about 40°. This shale contains a poor fauna of immature fragmentary '''goniatites'''. Note the excellent '''concretion''' horizons, formed at an early '''diagenetic''', pre-compaction stage.
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Take the footbridge across the river, and look right to confirm the orientation of the fault. About 50 m upstream from the bridge, close to the river, there is a good exposure of well-jointed, friable Middle Bowland Shale (basal Pendleian) which dips downstream (southeast) at about 40°. This shale contains a poor fauna of immature fragmentary goniatites. Note the excellent concretion horizons, formed at an early diagenetic, pre-compaction stage.
  
 
==== Locality 3 [SE 075 543] ====
 
==== Locality 3 [SE 075 543] ====

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