The Armorican Mountain-building

Abstract

As mentioned above, the highest parts of the Coal Measures in most of the British coal fields are barren of coal; the beds here are usually red sandstones and red shales, with some conglomerates, hence the miners’ term ‘Barren Red Beds’ for these horizons. In the Midland coal fields these pass up into really coarse conglomerates and breccias. Another important point is that marine bands cease to occur about halfway up the Coal Measures. All these facts point to increasing uplift of the British area, with uplands which had been subject to tropical weathering (to give the red colouring) undergoing increasingly rapid erosion. The next beds that can be dated are of Upper Permian age and rest with violent unconformity on the Carboniferous.