Guide to the geology of Mount St. Bernard, Charnwood Lodge, Warren Hills and Bardon Hill, Charnwood Forest

The excursion will take in areas (Figure 1) that exemplify the contrasting scenery of Charnwood Forest, with its craggy knolls separated by featureless tracts or smooth-sided valleys. This landscape is controlled by geology, and is caused by the influence of erosion on rocks with very different physical properties. The Precambrian rocks, which are the subject of this excursion, are extremely resistant to erosion. They represent the tips of an ancient, rugged hill range that is only now beginning to protrude through a covering of younger and much softer Triassic strata, the latter in turn blanketed by Quaternary deposits. Past workers have viewed Charnwood Forest’s topography as being a ‘fossil’ or an ‘exhumed’ landscape, because a mountainous topography on the Precambrian rocks was already in existence before being buried by younger strata in Triassic times, about 240 million years ago. This ancient landscape is dramatically revealed in the walls of Bardon Hill Quarry, which will be viewed from the summit of the hill. It is only now emerging because the covering of Triassic strata (and also Quaternary deposits) is being preferentially removed by modern-day erosion (see inset to Figure 2).