Porto Santo Rocks

21st July 2017

Ambition II was in Porto Santo harbour for 4 days while we explored the island, mostly using the bicycles and shanks’s pony. We also took a ride on an open-top coach, which went to the west end of the beach (which runs almost the length of the island), and high viewing points on the north coast, Pico Castello and overlooking the harbour. J was not happy about the high points, especially as the bus driver would drive one-handed round the hairpins and clifftops while gesticulating and talking to passengers behind him! Alternative modes of transport include hired quad-bikes and scooters (often to be seen driven by young guys with nervous-looking young ladies riding pillion) or better still small electric cars. But we have the impression they got to all the sites, then rushed by and saw less than the walkers.

IMG_0602_porto_santo_beachPorto Santo beach (from the town pier, east towards the harbour)

This island is one of a series of sea-mounts, some of which we passed over en route from Portugal. Most have long since been eroded away above the surface, but are still steep mountains beneath the sea. A large percentage of Porto Santo, mostly on the north side, has also gone, but what remains is still spectacular. Every roadside rock and slope has a story to tell, but mostly what you see is not a text-book example, so you have to make your own interpretation. Some are masses of volcanic rock – often cast into shapes by the cooling process (hexagons from slow cooling plugs, or pillows from underwater eruptions). The colours vary from reds and browns to greys and jet-black.

IMG_0771_morenoCliffs at Moreno showing basalt dykes injected into earlier volcanic rocks

There are beds of a unique local clay (formed from chemical breakdown of the volcanic rocks) and sand formed from fossil coral and shell fragments mixed with black specs of rock. You can see a sandstone bed with shell and bird-bone fossils, streaked with calcareous deposits and basalt dykes. It seems the island was a hot-spot at the edge of the Atlantic plate, early in the formation of that ocean. The early eruptions formed the base of the mountain underwater, providing a home for corals, molluscs and others. There were two later phases of volcanism, each cracking and heaving the older rocks and deposits, and pushing the mountains high above the sea. Because the plates moved between each phase, the magma was a bit different each time (acidity, silicone content etc). Hence the many types, shapes and colours of rock today.

IMG_0664_pico_ana_fereraHexagonal lava at Pico Ana Ferera

There are terraces cut all the way up the mountain sides, so at one time the island must have produced abundant crops. Unlike Madeira, where the terraces are still maintained and grow luxuriant crops, here they are all abandoned and there is almost no agriculture on Porto Santo island. Everywhere is arid and dry. The blame seems to lie in almost total deforestation combined with the introduction of rabbits and goats. Even so it’s a mystery how the high terraces could ever have been productive, as there is no sign of irrigation channels, only the deep channels cut into the hills and valleys by winter storm-water.

There is one walk not clearly shown on the maps – an old track from the harbour going east to a tunnel in the headland, leading round to the next bay. The path is somewhat eroded (hence the omission) but is a spectacular route for the sure-footed. R walked this way and then by road to the slopes of Pico Branco to the North, hitching part of the way back. J walked the first part of the route and then explored an abandoned complex including sports area and night club to the E of the harbour on the way back. The smell from the local refinery was intense at times, which probably had a role in the demise of the facility. We cycled twice to the West end of the beach, walked to Moreno to see the spectacular fissured cliffs, and R took the bike round Pico Ana Ferreira to see the radiating hex structure where the old plug is eroded in cross-section. Amazing sights!

IMG_0751_pico_brancoPath crossing a cliff of lava columns on Pico Branco

The beautiful long south-facing beach is of course what attracts most visitors to Porto Santo (Madeira having almost no sand). We had some very pleasant evening swims just next to the harbour. The marina itself proved expensive for us as it has changed hands and no longer does cheap deals (except possibly out of season). Some other boats anchored off the beach, and a few found space to anchor inside the harbour, both much cheaper options. But at least we had a secure berth in the often windy conditions. Here we met K & S whose Wylo gaff cutter Zahlia was anchored off the beach, when they came to enquire about our nesting dinghy (Kari’s Bolger design had met an accident under tow). After a bottle of wine, we agreed to meet up again in Madeira…

IMG_0719_raised_beachRaised fossil coral beach at the east side. Eroded by wind, this is the source of most of the sand on the south beach.

IMG_0635_pillowlavaPillow lava (formed under the sea) at the west end of the beach

To any visitor we would recommend the free Geodiversity map of Porto Santo, available from the Turismo office in town and at the marina office.

 

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