On the geology of the Old Radnor district, with special reference to an algal development in the Wool-hope Limestone

I. Introduction.

The district which forms the subject of this communication has received but scanty attention in geological literature since the time of Murchison. Only one edition of the 1-inch Geological Survey map has been issued, namely, that published in 1840, and no explanatory memoir has yet appeared. Two of the horizontal sections published by the Geological Survey, however pass through the district, and these throw some light on the views adopted by the officers of the Survey regarding its general structure at the time when the district was mapped. They regarded the rocks of Old Radnor Hill as altered May Hill Sandstone, and the surrounding limestone, together with that which occurs at Nash Scar 3 miles away to the north-east, as altered Woolhope Limestone.