486 PEOr. E. J. GARWOOD ON THE LOWEE CAEBOXIFEROUS [DoC. 1^12 r 



at a progressively earlier period as we approach the 

 uorthern end of the district: thus cutting out first the Gas- 

 tropod Beds, then the Miclielinia Zone, and finall}^ the highest beds 

 of the underlying Shap Dolomites. The upper beds of this sand- 

 stone also gradually replace the Cyrtina-carhonaria Sub-zone in the 

 same direction. As a result, the overlying Xerimtopliyllum-minus 

 8ub-zone rests directly upon the sandstone at the base of Hardendale 

 Xab. Even this sub-zone is almost merged in the sandstone at the 

 northern extremity of the district. At the same time, the thickness 

 of the Orton Sandstone diminishes in the same direction, from about 

 500 feet under Ashfell Edge to 200 feet or less in the neighbour- 

 hood of Shap. The net result may be summarized by stating that 

 the individual beds thin gradually when traced from south to 

 north. This thinning is not due to an overlapping of 

 the higher Carboniferous zones against the Lower 

 Palaeozoic laud-surface, for the Shap Dolomites continue- 

 uninterruptedly as far north as the district extends, but is due 

 to the wedge-liJve thinning of zone after zone in a northerly 

 direction. This would point to a more rapid deepening towards- 

 the southern end of the district, especially during the period when 

 the lower zones were being deposited. It will be best to describe 

 a typical section across the district in the neighbourhood of Shap,. 

 which may be supplemented by a description of the beds in 

 llaveustonedale where some of the zones are more 'fully developed. 



The Shap District. 



A general section across the district is shown in the accom- 

 panying diagram (PI. LVI, fig. 1). Starting near Shap Abbey it 

 traverses the Thysanoi)liyllum Pand, a little to the west of Shap 

 village. The section is then transferred along the strike to the out- 

 crop of the same band in Docker Peck. Erom here it runs nearly 

 due eastwards through Hardendale Xab to the base of the Upper 

 Dibunojyhyllum Sub-zone on Wickerslack Moor. At this point it is- 

 again transferred about 2 miles in a north-westerly direction, along 

 the line of strike, to Wintertarn Quarry. Erom' here onwards it 

 traverses the higher beds of the Dihunopliyllum Zone, until they- 

 disappear under the Permian rocks in the neighbourhood of King's- 

 Meaburn. 



The AtJiyris-r/Iahristria Zone. 



The lowest beds are exposed on the right bank of the River 

 Lowther in the cliff opposite Shap Abbey, while the upper portion 

 of the zone is well seen in Docker Peck, a little to the south of 

 Shap village. 



The Pasement Peds here consist of some 30 feet of irregu- 

 larly - bedded shaly sandstone and conglomerate; they contain 

 pebbles of the underlying Ordovician rocks, together with frag- 

 ments of Shap Granite. 



