The geological history of the Maltese islands wasn't as peaceful and stable as currently. In fact, the Maltese islands shows evident signs of violent seismic activity. If you visit the northern part of Malta, you'll notice differences in the height between places. These are called faults. The most prominent fault is Victoria Lines fault, mostly because the British used the fault line to their strategic advantage, by building the Victoria lines wall.
The Victoria lines fault runs across Malta from Madliena in the east, to Fomm ir-Rih in the west. This fault is part of the Great fault of Malta which is made up by a series of faults all around Malta. These faults in turn make part of a series of more complex faults in the middle of the Mediterranean sea. The Maltese islands (and Sicily) lie on the northern part of the African tectonic plate, which is travelling North. Colliding with the African plate is the Euroasian plate which is travelling to the north east on a slower pace than the African plate. This tectonic movement gives rise to earthshattering earthquakes and volcanoes. A cataclismic event took place in the middle of the Mediterranean sea which gave rise to significant shifts in the geology of the Maltese islands.
The evident sign of this event is the V shape fault system in Malta. This runs from Madliena to the east to Fomm ir-Rih to the west and from Gozo to the north west to Birzebbuga to the south east (known as the Maghlaq fault). This gave Malta the current landscape with Horsts and Valleys. A Horst is a formed where part of the rock sediment gets pushed up between to smaller faults. An example of such horst is Wardija (near Burmarrad), which stands higher than the surrounding area. A rift valley is formed where the faults move apart from each other causing the central part to sink below. At your current point (in the Gharusa tal Mosta garden) you standing near the edge of the Victoria fault line.
Now to the cache: To log a found, please send me an e-mail and answer the following Questions:
- What is the height of your standing point above sea level (in metres)?
- Malta is made up of a stack of rock sediments, can you name and describe at least 2 of the rocks which are present in the area? Please explain your answer.
- Look towards the Burmarrad/Wardija area to the north/north-west what, in your opinion fits most for this area, a Horst or a rift Valley? Explain your answer and include details on why you think so.
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It would be nice, if you could take a photo of you or your gps with Burmarrad in the background. You can log this freely, after sending your e-mail. I will contact you, in case of problems with the answers.
Hope you learn more about this area (and Malta in general) and hopefully enjoy the nice views.
