There are questions and a task you will need to complete to claim this EarthCache and you will need to bring a measuring instrument such as a tape measure. Further information below. Getting to the GZ can be a little tricky so please follow the navigation instructions below carefully. Two further caches “The Best Views” GC27X8H and “New Heights” GC27X81 can be accessed from the same route and are just a short distance up the Lizard.
GETTING TO THE CACHE
The track is off the Napier - Taihape Rd so we suggest you park your car at S 39° 25.566
E 176° 24.957 then cross the road. Follow the 4-wheel drive track for 60 metres, on the left a smaller track starts at S 39° 25.586 E 176° 24.923. Enter the bush and follow this track until you reach a large rock at S 39° 25.751 E 176° 24.751 (also WP1 for GC27X8H which may contain handy navigation cards). Just be careful when its wet as parts of the track will be slippery. At S 39° 25.762 E 176° 24.737 look left for a white ribbon. Join the track uphill from here. Continue to S 39° 25.801 E 176° 24.704 here you will find more ribbon markers, continue on the track ( don’t enter the small clearing nearby ). Continue on to S 39° 25.854 E 176° 24.653 following the white ribbons until you arrive at the GZ.
GEOLOGY
The Hawkes Bay district separates readily into three regions of geological structure; the main forms of the eastern Wellington district are continued into Hawke's Bay. The western boundary is formed by high, rugged mountain ranges running south-west — north-east and composed of Triassic-Jurassic greywacke. The east is characterised by broken, hilly country formed from Cretaceous and Tertiary sediments. Here complex earth movements have upthrust small ridges or tilted blocks, exposing anticlinal cores of late Cretaceous rocks. The third region, which is a continuation of the wide Wairarapa trough from Woodville through the Takapau Plains to Mohaka and Wairoa on the shore of Hawke Bay, is filled with thick Upper Tertiary and Pleistocene sediments.
The Kaumatua fault is located within this third region in an area known as the Kuripapango-Ngamatea region and is a Neogene uplift and transgressive sedimentation that occurred during the late Miocene period (5 - 10 million years ago.) The late Miocene period was a time of global drying and cooling. As ice rapidly accumulated at the poles, sea-levels fell, rainfall decreased and rainforests retreated. Many plant and animal groups died out and other forms, better adapted to a drying world, took their place.
During the late Miocene period it began initially as alluvial fan and braid plain deposits, but became a fully marine up sequence. The Kaumatua fault consists of interbedded lithic grainstone (grain-supported carbonate rocks with NO mud), sandstone (sedimentary rock composed mainly of sand-sized minerals or rock grains), and mudstone lithofacies (hardened silts and clays). Ash from Tongariro thought to be 20 million years old has also been found in the formation.
Sandstones interbedded with lenticular grainstones is the characteristic that gives the Lizard formation its name. The grainstones are offshore bioclastic ridges or bars that pass laterally into the surrounding sandstone lithofacies. The formation dips approximately 60° west back towards the Ruahine Fault. The formation is approximately 150 m wide.
As you walk up the feature you are walking directly on top of the uplift or fault line. The fault itself extends much further than the clearing you will visit. In fact you are walking on the fault almost as soon as you leave SH50 but only becomes apparent when you reach the clearing at GZ.
Once you complete the following EarthCache requirements you can post your find without delay, as per the EarthCache guidelines. You will also need to verify your find by sending us a message with your answers to these questions and we will answer in due course:.
1. Use the text "Kaumatua Formation - The Lizard - GC2BVRD" in your email.
2. Go to S 39° 26.060 E 176° 24.586. What is the altitude here?
3. At this GZ the grainstone which passes laterally up the feature is clearly visible. What is the average distance between the lateral grainstone here?
4. Bioclastic ridges consist of what sort of material?
5. The sandstone and mudstone interbeds of the feature are what distinctive colour?
6. (Optional) Take a picture of yourself and/or your GPS with The Lizard in the bakground. (Just post the photo with your log – no need to email this)