Excursion report: The Nuneaton Ridge

September 15th 2007

Everyone of a geological turn of mind must be aware that we are in the midst of a couple of memorable celebrations, one of which is the 200th anniversary of the foundation of the Geological Society of London, the country’s leading geological society. Many of the country’s other geological societies were invited to arrange events to mark this momentous occasion, and our neighbours, the Warwickshire Geological Conservation Group, offered to host a field excursion to one of their county’s best localities, the Nuneaton Ridge. The Geology Section was invited in its turn by the WGCG to join in, which we were very pleased to do. Despite its closeness to Leicester, the Ridge is not a familiar stamping ground for the Section. The Ridge is a small, but fascinating, narrow strip of relatively high country bounded by faults and enclosing a sequence of mainly Cambrian sedimentary rocks, intruded by Ordovician age sills and dykes. These harder intrusions have long been exploited for building and, mainly, road metalling, and on September 15th we saw two of the quarries opened to extract this material, which perforce also expose the Cambrian country rock. We also walked the Moorwood Trail, which runs through the Hartshill Hayes Country Park, a trail designed to show off the scenic aspects of the ridge, and the various natural and artificial rock exposures.

(Right): The party enters the disused quarry at Mancetter

We were not the only other group invited to join the WGCG, and it is to their credit that they broadened the net to include civic groups and other non-geological organisations. It is always constructive to fly the geological flag in the wider world. Even the weather chipped in and helped us, and stayed fine throughout. With all the extra folks I lost count at 50 when trying to assess the size of the throng that milled around at our first stop, a large disused quarry near Mancetter. Martyn Bradley and Maurice Rogers attempted to explain the logistics of the day and impress on us the importance of observing health and safety requirements, but that was never easy with so many. Alan Cooke took over to lead us into the quarry, and gave us the benefit of many decades of study in that place. The main draw for the majority of the party, apart from a bracing walk in the countryside with friends, was the opportunity to search for trilobites in the Cambrian shales, with many species and fine specimens recorded. Sadly, we were largely disappointed, they were hiding and only a few scraps were collected. But the interest inherent in the nature and field relationships of shales and intrusions more than compensated for most of us.

(Left): One of the numerous small quarries on the Nuneaton Ridge, showing a sill (below) intruding Cambrian shales (above)

Across the road from the disused quarry is its working counterpart, and despite not being able to enter the facility, we were taken to a good viewpoint from where we could overlook operations in the quarry. From there some of us chose to walk to the afternoon locality of the nearby Moorwood Trail in the Hartshill Hayes Country Park, whilst others returned to the cars at the disused quarry to consume lunch and discuss the morning’s activities. This group then drove to the Park and rejoined the walkers. Many people left us at lunchtime, but the remaining group of enthusiasts enjoyed an excellent perambulation around the Nuneaton Ridge under the guidance of Martyn Bradley, making a special study of the many excavations opened to exploit the intrusions. We also had a glimpse of the contact between Westphalian measures and a sill. Unfortunately we had to return to the cars via the same route we took on the outward leg, and without the stimulation of scenes of new interest, we were quite weary as we regained the car park. However, nothing could detract from an excellent day, for which we must give full credit to our Warwickshire comrades.

Andrew Swift