This easy-to-solve earthcache lures you to a great view of Ghar Hanex Nature Reserve.
Here is a small but very beautiful natural arch (like the gone azure window at Gozo), where you can see the forces of the sea very well.
Natural arches are created by erosion in the microscopic and macroscopic area. Microscopically this is, for example, the dissolution of cement, macroscopically the formation of fracture by e.g. tectonic processes. Both types of formation can be separated or combined. Most natural arches are formed from narrow fins and sea stacks composed of sandstone or limestone with steep, often vertical, cliff faces. The formations become narrower due to erosion over geologic time scales. The softer rock stratum erodes away creating rock shelters, or alcoves, on opposite sides of the formation beneath the relatively harder stratum, or caprock, above it. The alcoves erode further into the formation eventually meeting underneath the harder caprock layer, thus creating an arch. The erosional processes exploit weaknesses in the softer rock layers making cracks larger and removing material more quickly than the caprock; however, the caprock itself continues to erode after an arch has formed, which will ultimately lead to collapse. (http://www.wikiwand.com/en/Natural_arch)
At this arch the force of the surf conveyed sand and stones, which created this arch out of the rock.
Ultimately also this rockgate is destroyed by the erosion. But until that happens we can enjoy it. There is no reason to mourn, because the next arches are already forming.
On coasts two different types of arches can form depending on the geology.
On discordant coastlines rock types run at 90° to the coast. Wave refraction concentrates the wave energy on the headland, and an arch forms when caves break through the headland.
On concordant coastlines rock types run parallel to the coastline, with weak rock such as shale protected by stronger rock such as limestone. The wave action along concordant coastlines breaks through the strong rock and then erodes the weak rock very quickly.
Before you can log this Earthcache, you just have to answer the following questions by message or mail:
1. Look at the arch in front of you. What do you think, is the coastline here, concordant or discordant?
2. The rock is crucial for the creation of a natural arch. Which rock is located around you?
3. Look around exactly. How many "windows" can you recognize? (like the gone AzureWindow)
4. Optional: A photo of you in front of the natural arch.
If you want you can also get closer to the natural arch.
But please be careful about the slopes and stay on the trails!