With its reef, lagoon, lighthouse and Castle Rock, Castle Point is one of Wairarapa's most spectacular landforms. Castlepoint settlement takes its name from Castle Rock, the impressive rock outcrop at the southern end of Castlepoint Scenic Reserve. Castle Rock was named by the British navigator James Cook in 1770, who was struck by it's similarity to the battlements of a castle.
Castle Point is made of successive layers of limestone and sandstone, deposited millions of years ago. Many fossils and shell fragments can be seen throughout these layers, which tells us that it was created under the sea and due to tectonic and seismic activity, has since been pushed up.
Due to fault lines on either side of the reef, nearby older and softer mudstone strata have also been uplifted, but subsequently eroded away. This erosion has exposed the harder limestone of the reef which stands proud of the surroundings. This can be seen on the seaward side of the reef (which sits on an older base of siltstone) as a dramatic cliff.
The relatively erosion resistant reef shelters the tidal lagoon and is attached to the mainland via a sand tombolo. This tombolo was formed as wave actions deposited sediment over time.
The Earth Cache
To complete this earth cache please email me the answers to the following questions (include your username and the name of this cache). Please do not post answers in your log. You may log your find as soon as you have emailed the answers to me i.e. you do not need to wait for permission. I will be checking logs and email you if there is a problem. Please no cheating it just spoils it!
Question 1. The rocks that make up Castle Rock and the reef are considered young. How many million years ago was the uplifting of the reef from underwater to above ground?
Question 2. Abundant fossils found throughout the reef tell us that the rock layers were formed underwater. What else do they tell us about the seas in which the layers were formed?
Question 3. Look across to Castle Rock from the reef - in your own words describe how high you think Castle Rock is? e.g. is it as high as a house or Auckland Sky Tower or.... ?
Optional. Look for different rock types, layers, formations or fossils, take a picture and post this with your log.
Please enjoy and respect the area. Happy Earth Caching!