The Long View

'Cardigan Bay' refers to most of the area off the west coast of Wales, from the Llyn peninsular sticking out in the north west, curving round past Snowdonia in the north, Aberystwyth in the middle to Cardigan in the south (and maybe on to Fishguard or St David's Head in the far south west - boundaries in the sea are seldom precisely defined)

We drove a few kilometers up the coast today and walked to a vertiginous high point about 170m above the water. I think English lacks a word: what is a slope called if it is too steep to be a hillside but not sheer enough to be a cliff? I expect there is something in German. We were on a narrow path about a metre wide, with the ground falling away below us, in a wind of force 6 or 7. 

I'm not great with heights and this was enough to trigger the first tingling of vertigo, but the payoff was a great many pictures of the coastline snaking away from us; waves breaking far below and water raging in tiny inlets, where the sea - or a descending stream - has found a weakness in the rock. Cloud cover was quite low and dense, the atmosphere damp, the light subdued. It's curious - and we have experienced this before on this coast - that these (and not cloudless, bright days) are exactly the right conditions for seeing long distances. We could follow the bay all the way around and see the outline of the hills of Llyn, over 70km away

I've tried several times to understand the geology that underlies the spectacular and varied rock formations of the neighbouring Pembrokeshire coasts. Sadly, it is complex and includes a lot of diffrrent rock types, and I've only ever grasped parts of it. Ceredigion, by contrast, seems blissfully simple. All the rock here was created from marine sediments over a 50 million year period, roughly 485 to 435 million years ago, the Ordovician and early Silurian periods, just as plants and insects were starting to leave the ocean and colonise land

The rock types are sandstone (made from sand on the ocean floor), siltstone (silt is just sand that has been eroded into even finer particles) and mudstone (mud is made of clay, which is the ultimate erosion product, when silt is broken down into its constituent clay minerals) 

The simple geology doest not mean the exposed rocks are dull. During half a billion years, they have seen immense changes to the face of the earth. Continents moving across the surface of the planet, colliding into one-another, raising up mountains, deforming rocks and folding sedimentary strata. This particularly vivid example, from the edge of a small beach, shows the many layers of different rock types formed across all those centuries, and evidence of the violence they have been subjected to