The photo is Filfla, the rock island that split off from the cliffs around Ghar Lapsi. It looks like an aircraft carrier on the horizon which is probably why the British decided to use it for bombing target practice when they were the dominant power. It is now protected and is home to an endemic lizard and many seabirds.
The short course I am doing with the University in their old building in Valletta is called "Maltese Natural Heritage" and offers four lectures on Wednesday evenings and two field trips. Ghar Lapsi was the first of the field trips and was designed to illustrate the excellent lecture on the geological formation of Malta. I missed the second lecture in the series because I was in Catania and I was relying on an email message from the administrator of the course to inform me about directions for the field trip scheduled for the Saturday on the day after I returned. When I checked on Friday night I learnt that I could meet up with two other students outside the Hotel Phoenicia in Valletta and would be picked up for the drive to Ghar Lapsi.
Most of the other students on the course are either in Upper Secondary school or undergraduates. I arrived early at the appointed spot and after a while a young man turned up and I decided he looked like he was going on a field trip so we introduced ourselves. Next a young women arrived but I thought from her shoes and handbag that she wasn't field trip material so we all stood a little separate and waited. Our pick up was late but arrived with another University student full of apologies. I discovered on Wednesday night that this was another of the lecturers on the course whose speciality is fauna. The young woman was also going on the trip so we all crowded into the back seat and set off.
The driver/lecturer seemed very skillful in navigating the back streets of Malta and assured us we would get to the meeting place on time. He shot off down and around Marsa avoiding the main road that was crowded with traffic and somehow found country roads that took us down to Ghar Lapsi from a direction I hadn't been before. He made conversation with the young people by asking them about the courses they were doing but it was hard work for him. We passed a herd of shoats (perhaps the same herd I noticed before on the Ghar Lapsi garigue) and he and the young man in the front seat who was perhaps a postgraduate student talked about how it was a rare sight these days and that was a good thing because they ate everything they found. We did arrive at the meeting place on time.
Ghar Lapsi was chosen because it shows very clearly the sedimentary rock structure as well as quaternary deposits left by river action after Malta emerged from the sea. There is a fault line running all along the base of the cliffs on either side of Ghar Lapsi and in several places we walked along the edge of this fault line. We set off in the opposite direction to the way we had gone with Ramblers Malta. It was a lovely day but very windy as we walked along the edge of the sea with the cliffs high above us and a stretch of rich garigue between us and the cliff. The leader stopped often to point out the key features and at first the track was easy to follow.
I had noticed the caves in the upper cliffs on our previous visit and our leader explained that these were formed by wave action and showed that at one stage the sea had been much higher than it now is. His teaching style was to try and encourage us to read the story that was in the landscape. The edges of the fault line told the slow but violent tale of rock grinding over rock for thousands of years, squashing some rocks into a different form and scratching out lines and half circles on the sheer cliff faces as rock slid or pivoted on rock.
At two points along the walk we crossed ancient river courses where water would pour through the cliffs and leave their deposits as the river flattened out briefly before entering the sea. Here the story to be told is of weather patterns over the years. Boulders are laid down in layers and the size of the boulders in each layer can be distinctly read and tells us how forceful the flow of water was in that year. Fine sediment indicates a long period of stability when large shrubs took root. When the river became active again the shrub was washed out leaving a rhizome root cast that in turn is filled with sediment and writes the story of an ancient shrub.
During periods of draught, the water dries out completely and leaves layers of calcium deposits in the fine sediment so we can read several ages of dry climate. But there are also places where huge boulders have been deposited in a semi-circle into the fine sediment and this tells of a powerful flow of water that carved a path back into the fine sediment.
In these quaternary layers, ancient bones have been found similar to those found at Ghar Dalem and whilst we were there, one of the school students found a rock that showed several different fossils. The inclusion of a sand dollar indicates that the rock had been laid down under the sea, uplifted as part of the cliff when Malta emerged and then washed down the river to be deposited once again in the quaternary sediment. The look on that young man's face told a story of his dreams for a future career!
Our leader also pointed out some of the flora that we encountered along the way including Maltese splurge and sea lavender. That will be the focus of our next field trip this Saturday.
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