Cathedral Gully
A badlands (also badland) is a type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded by wind and water.
This specific area is made up from calcareous siltstone. it is a natural badlands, although man-made badlands do exist.
It has come about due to the combination of soil, the aspect of the gully to the prevailing weather, and the interplay of the drying hot sun, wind and rainfall.
In this location the erosional forces have left a distinctive set of "spires" reminiscent of Gothic cathedrals which in turn has inspired its local name of "Cathedral Gully".
The siltstone in this area is calcareous. Calcareous sediments are usually deposited in shallow water near land, since the carbonate is precipitated by marine organisms that need land-derived nutrients. Generally speaking, the farther from land sediments fall, the less calcareous they are.
Another , internationally known example are the Putangirua Pinnacles – formed by the erosion of the conglomerate of an old alluvial fan – and these are located at the head of a small valley near the southern tip of the North island.
Tasks to perform to log this cache
1. Badlands are known for being hard or even impossible to navigate due to the steepness of the terrain. Estimate the spires' angle to the vertical. Report this to the cache owner by email - do not post as part of your log.
2. Siltstone is a sedimentary rock which has a grain size in the silt range, finer than sandstone and coarser than claystones. Using the Krumbein phi (φ) scale, what range does siltstone occupy on that scale? Report this to the cache owner by email - do not post as part of your log.
3. Siltstone may contain concretions. Look at the formations, and come up with your own answer as to the presence or absence of concretions in this location. How has the absence or presence of concretions affected the ultimate shape of the eroded siltstone? Report this to the cache owner by email - do not post as part of your log.
4. As the siltstone in this area is calcareous, would you expect to find fossils in this area, and if so, what type? Report this to the cache owner by email - do not post as part of your log.
5. Please take an altitude reading at the lookout. At a minimum, how many meters has this land mass moved since it was created, up or down? Report this to the cache owner by email - do not post as part of your log.