Geological Mapping at Rinsey Cove

The Lower Sixth Geologists enjoyed their first experience of geological mapping at Rinsey Cove, near Porthleven, last Friday. In glorious weather, they were tasked with carrying out a range of observations and measurements that would enable them to reconstruct the geological history of the area. This gave them first-hand practice at carrying out techniques that they will have to refer to in their C1 practical exam next summer. They mapped the contact between the Tregonning Granite (featuring xenoliths, pegmatites and tourmaline mineralisation) and the Mylor Slate formation (exhibiting different grades of contact metamorphism).

After completing their maps, the group visited Praa Sands to examine an ‘Elvan’ dyke. They examined the dyke’s features to interpret its formation and collected data about the orientations of phenocrysts which they will analyse back in the classroom to determine whether there is a statistically significant trend.