WHAT'S HERE?
LEARN ABOUT IT
The area was once under a large, shallow sea that extended over most of the Canterbury region from the Late Cretaceous. This has been uplifted from the ocean floor to where it is today from around 22 Million years ago. Pressure over time has caused extensive uplift, folding and faulting of the surrounding Torlesse and Craigieburn Ranges (Torlesse Supergroup basement rocks, Mesozoic aged) that frame the Castle Hill Basin.
Since being exposed at the surface in their present location the limestone rock has been eroded by water into these distinctive sculptured landforms, called a karst landscape. The word "karst" is named after the region Karst in the country of Slovenia that is characterised by numerous sinkholes and extensive limestone cave systems.
The limestone units present here in the Oligocene aged Thomas Formation can also be found in other similar aged (Oligocene - Eocene) units of the Amuri Limestone and Omihi Formation at many locations around Canterbury, including Weka Pass and the greater Waipara region, the Kaikoura Peninsula, inland Timaru and Oamaru. These were all formed around the same time as part of the vast shallow sea.
HAVE A LOOK!
Can you identify any visible fossils in the limestone? Look for shell fragments of molluscs, bryozoans and echinoderms.
At the base of this limestone unit, volcanic tuff deposits (from small explosive volcanic eruptions into the shallow sea) can be found. These are composed of basalt and as such have a blackish brown colour (due to the iron content). Can you spot any soft black brown soil or brownish colouring to the limestone poking out from the bases of any of the tors?
On the left hand side of SH73 when coming from Christchurch. Well established DOC signed carpark with toilets.
Can be exposed in winter! Be careful of ice on the ground around shady rocks. Take extra care if climbing on the rocks with steep slopes and cliff edges and occasional slippery surfaces.
Because this is a significant protected site, visitors should all be aware of the following codes of conduct:
Dogs are not permitted in this reserve
Stay on the access track - the paddocks are private property.
Use the provided toilet facilities.
Refrain from digging holes or disturbing the ground surface - wahi tapu (sacred places) are here.
Avoid trampling on endangered plants - use open spaces between rock outcrops rather than the bases of rock faces.
Respect fenced areas.
Take all rubbish away with you.
Do not mark the surface of the rocks.
Consider others in the area.
Rock climbers must follow the climbing code of conduct.
Well formed and signed graded path from the carpark to the start of the rock outcrops.