The unfinished obelisk is the largest known ancient obelisk, located in the northern region of the ancient quarries in Aswan, Egypt. It is nearly one third larger than any Egyptian obelisk ever erected. If finished it would measure around 41 meters (which is 90 cubits), or 137 feet, in length (it was recently measured from base to tip its length being 41.88Mts). Its weight is estimated at around 1,150 metric tons. Scientists speculate that it was intended to complement the so-called Lateran Obelisk which was originally at Karnak and is now outside the Lateran Palace in Rome. The obelisk's creators began to carve it directly out of bedrock, but cracks appeared in the rock and the project was abandoned. The bottom side of the obelisk is still attached to the bedrock. The unfinished obelisk offers unusual insights into ancient Egyptian stone-working techniques, with marks from workmen's tools still clearly visible. Besides the unfinished obelisk, an unfinished partly worked obelisk base was discovered in 2005 at the quarries of Aswan. Also discovered were some rock carvings and remains that may correspond to the site where most of the famous obelisks were worked. All these quarries in Aswan and the unfinished objects are to become an open-air museum and are now, since 2006, officially protected by the Egyptian government as an archeological site.
Being at the quarry, just how did they create these giant single pieces of rock out of the mountainside? They made a row of holes app. 10 centimeters (4 inches) wide, and inserted wood in the holes. Then they poured water on the wood. The wood then expands by such force because of the water that the rock splits. The basic shape of the obelisk is created by rows of workers pounding the shape on the rock with dolomite rocks, or dolostone, and creating the approximate 1 meter (3 feet) wide shafts at each side of the obelisk-to-be. This is possible because the dolomite is even harder than the rock being worked on. To smooth the sides of the obelisk, bricks are heated and put on the places that are to be treated. When the rock is sufficiently hot, cold water is poured on, and the uneven parts come off in flakes, thanks to the crystalline structure of the mystery rock.
To log this cache, you will have to complete the mandatory photo requirement and message me the answers to the question below:
1) Take a picture of yourself or your geocaching group at the site of the unfinished obelisk and post the photo with your log. Your face is not required if you don't want. (this is mandatory)
2) Identify what type of rock it is that the obelisk is made from. Be specific.
3) Once you identify this rock, tell me what type of rock it is. (Igneous, Metamorphic, or Sedimentary)
4) What is the worldwide average of the average proportion of the different chemical components (ie. the chemical composition)of this rock. (Can be found on the internet)
Most of all, have fun, this is a very cool location.