21. Southerly flowing rivers from this same landmass were responsible for the Millstone Grit / Marros Group succession in South Wales. 22. The reserve covers and has a varied geology with Old Red Sandstone below the cliffs and Millstone Grit above them. 23. Rochdale Town Hall is wide, deep, and is faced with millstone grit quarried from Blackstone Edge and Todmorden. 24. The Pennine Coal Measures Group is preceded ( underlain ) by the Millstone Grit Group which is of Namurian age. 25. The areas of Millstone Grit form an'inverted horseshoe'around the lower uncapped limestone areas of the White Peak. 26. The church was built of millstone grit and the detached spire of the mid-14th century looks to be earlier. 27. To the east is the valley of the Burbage Brook, which is overlooked by Burbage Edge, a Millstone Grit escarpment. 28. A millstone shaped from Millstone Grit quarried in the area has been adopted as the emblem of the Peak District National Park. 29. This is a late-eighteenth century single arched humpback bridge, made of millstone grit , and is grade II listed. 30. The catchment lies on carboniferous rocks of Millstone Grit , and is heavily reservoired, with 39 reservoirs licensed to provide water.
