This is an Earthcache and so there is no physical container to find at GZ. Instead, you will need to make careful observations of the rocks in the sea defence at the posted co-ordinates and answer some questions about them. There is no need to scramble on to the rocks to answer any of the questions; everything can be completed from the path.
Rock classifications
Igneous rocks form when molten rock (magma) cools and solidifies. Depending on the rate of cooling, igneous rocks can have differing crystal sizes and hence properties. Typical examples of igneous rocks include granite and basalt. Interesting crystal structures can be a particular feature of igneous rocks.
Sedimentary rocks are formed when existing rock is weathered and eroded which creates fine particles that are then transported. These particles are then deposited to form layers of sediment which build up and become compressed over millions of years to form sedimentary rock. Examples include limestone, sandstone, shale, chalk and coal. Sedimentary rocks are important for the study of fossils (Palaeontology), as animals and plants can become trapped in the layers of deposition and fossilised as the rock forms.
Metamorphic rocks are formed when existing rocks undergo further physical and chemical transformations when placed under great heat and pressure. Examples of metamorphic rocks include marble, slate, gneiss (pronounced ‘nice’) and schist. Metamorphic rocks can feature contorted bands of minerals known as foliation.
Questions to answer
Q1. Carefully observe the rocks at the posted co-ordinates… based on the features that you see and the descriptions above, what classification of rock is used for the sea defence? Describe examples of some features that you can see to support your answer.
Q2. As you stand at the posted co-ordinates, you will see a large part of a single item in a rock adjacent to the path. What shape is this feature and measure (or estimate) its diameter? A ‘bonus point’ if you can name the feature.
Optional: it would be nice to see pictures of the view out over the water taken from the published co-ordinates to see different tidal ranges, weather patterns and sea states.
Please send your answers (via either the message centre or email) before logging your visit.
Please do not post any photos or descriptions of the rocks or features relating to this Earthcache in your log.
Update - July 2018: It would appear that someone has taken it upon themselves to paint the object at GZ. Why they felt it was necessary is beyond me but I hope it doesn't spoil the experience.
