This is an EarthCache. As such, there is no container to find at the coordinates. To log this EarthCache, please click the email link in the profile and send a message with the answers to the four (4) questions listed below. Photos of you or your group at the Natural Tunnel would be appreciated, but not required to log a find.
This EarthCache will take you along the Ruakuri Bushwalk to the Natural Tunnel. It has been voted one of the best short walks in New Zealand. It should take about 30 minutes to complete.
The posted coordinates will take you to the parking lot and the trail head for this Bushwalk. It is an easily graded, gravel track with some stairs. By walking the loop, you will find information displays with the answers you need to log this EarthCache. Please keep to the track at all times. The Ruakuri Bushwalk is available 24/7. Please note, the cave itself is private property - the only way to visit that is to take a guided tour. We took the blackwater rafting tour through the cave and had a great time!
Caves (or caverns) are naturally formed underground chambers. Limestone caves, such as the Ruakuri Cave, are formed when slightly acidic ground water dissolves limestone along joints and bedding planes, opening up cavern systems as calcite is carried away in solution.
When rain falls, it seeps through soil and leaf litter picking up carbon dioxide on its way. A weak carbonic acid solution is formed. This solution drains into cracks in the underlying limestone slowly dissolving the rock. The cracks widen and more water flows in. Cracks widen into channels, chanels widen into tunnels, and a cave is born.
1) According to the sign titled Crumbling Caves (S38 15.974 E175 04.565), vertical cracks enlarge to become what?
2) Describe how the Ruakuri Natural Tunnel was formed.
Karst landscapes are characterised by caves, natural arches, tunnels, depressions and sculptured rock outcrops. All of these features are created by the powerful action of water on limestone. Water, you can't walk on it ... you can't hold it - yet water can eat away mountains, crumble cliffs, grind boulders down to tiny pebbles, and as you will see, it can hollow out hills.
3) According to the sign titled The Power of Water (S38 15.952 E175 04.534), what is one of the key ways to keep a cave healthy?
4) What four things does the sign say will happen if the cave is not kept healthy this way?
Glowworms:
After dark the track is equally as spectacular. Glowworms, almost invisible by day, illuminate the damp banks alongside the track with their tiny lights. The best place to see them is at either side of the swing bridge. Bring a torch to help you along the track, but for a magical experience, turn your lights out when you stop to see the glowworms.
Please note the Environmental Care Code for this area:
* Protect plants and animals
* Remove rubbish
* Bury toilet waste
* Keep streams and lakes clean
* Keep to the track
* Consider others
* Respect our cultural heritage
Enjoy your visit. Toitu te whenau - Leave the land undisturbed.
Permission for this EarthCache was granted by the Department of Conservation, Maniapoto Area Office.
EarthCache Supporter
