The Chatham Islands |
 Geology: There are three types of rock: igneous rocks (which have cooled from hot volcanic magma), sedimentary rocks (such as limestone and sandstone, which have accumulated in fluids and then been laid down as sediment), and metamorphic rocks (which are rocks that have had their crystalline structure altered under pressure). This is a close-up photograph that I took of schist – which is a metamorphic rock – on the north-east coast of Chatham Island. The orange lichen on the rock helps to highlight the folds in the rock that were caused by intense pressure. |