The Lesser known side of the Golden Gate EarthCache

This very pretty area has some really beautiful sandstone cliffs. They aren't as dramatic as the Golden Gate ones, but worth a visit. It will only take a short while to gather the info needed for this earthcache.

The world famous Golden Gate sandstone is that which we see in the beautiful Golden Gate national Park. There are however, a few pretty spectacular examples of the beautiful orangy/yellow sandstone cliffs on a very quiet dirt road which runs down towards Sterkfontain dam and a well known holiday resort.

Sandstone is a sedimentary rock composed of sand-size grains of mineral, rock, or organic material. Sandstone is one of the most common types of sedimentary rock and is found in sedimentary basins throughout the world. It is often mined for use as a construction material or as a raw material used in manufacturing.  

It is quite possible that, given a few million years, these arch-like shapes might erode into the spectacular and delicate arches, like the one below, that are found in Arches National Park near Moab, Utah.

Amazingly, the geology of this area forms part of the Karoo Supergroup, The Karoo Supergroup is the most widespread stratigraphic unit in Africa south of the Sahara Desert, non-marine origin, deposited about 120 million years ago.

(Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks.)

In southern Africa, rocks of the Karoo Supergroup cover almost two thirds of the present land surface, including all of Lesotho, almost the whole of the Free State, and large parts of the Eastern and Northern Cape, Mpumalanga and KZN. Karoo supergroup outcrops are also found in most of the neighbouring countries, as well as on other continents that were part of Gondwana.

To qualify to log this cache, please answer the following questions and submit your answers to us via email:

1. Describe the sandstone layers that you can see at GZ?

2. What could mined sandstone be used for?

3. What is the study of stratigraphy?

4. What beautiful man-made feature can you see in the distance opposite the cliffs at GZ?

References:

1. https://en.wikipedia.org/wiki/Karoo_Supergroup

2. http://www.berg.co.za/geology.htm

3. https://www.google.co.za/search?q=sandstone+rock