Great Geology Lunch Spots No. 3: Eas Fors, near Ulva Ferry, Mull

I had a visit out to Ulva Ferry today. There are loads of nice places over that way to stop for lunch and my favourite has to be the Eas Fors waterfall at Camus an Lagain just north of Lagganulva. Its easy to get to although the path was a bit soggy today. It is a great waterfall with some really interesting geology near by. Because of the amount of rain , the waterfall was fairly pouring over the edge today. Here are some photos:

First up however is this view from the track looking up the cliff above the main road - there is a red bole bed in there that is very obvious and very red. It is also quite thin and forms a very distinct layer. I went for a closer look later

Red bole in cliff above road

Moving on to the waterfall. The rocks above are basalt lavas for the most part plus some mugearites. There is also an obvious volcanic ash at the base - this also extends out along the shore.


Eas Fors in full flow

Sun came out and I got a rainbow in the waterfall

The clouds in the sky were impressive:

Clouds in the sky, Ulva in the distance

Another look over to Ulva:

The trap featuring is obvious in the lava flows on Ulva. Perhaps not as spectacular as the lava flows in Ardmeanach, but impressive nonetheless.

Moving down the beach a bit, the tide was very low today so I got to see some stuff I hadnt noticed before. Here is the fall seen from the ash layer near the waters edge


The ash is a sort of light brown to cream colour, quite different from most of the lavas which tend to be dark grey. At this location the clasts in the ash are quite small - didnt see any large fragments. Further back along the shore nearer to the mugearite plug of Na Torranan, there are much larger clasts and bombs in the ash. As well as some rather neat dykes cutting across it

Here you can see the ash in the foreground and lavas in the cliff where the trees are. Layering in the ash is obvious

Some of the basalts on the shore show the polygonal columnar structure that is well seen in Ulva itself:

Columns seen end -on. Rucksack for scale

After that it was a case of back to the car, but I nipped up to the main road first to get a closer look at that red bole I saw earlier:


It is quite thin, no more than 10 cm thick I would say. Some researchers have suggested that rather than being a weathered top of a lava flow, that some of these red horizons are actually tuffs, volcanic ash. I was wondering if this was an example of this.  This paper looks at this subject in detail:

Red tuffs in the Palaeocene lava successions of the Inner Hebrides

It is quite inaccessible from the road although a short abseil from above would get to it!

Anyway, it was time to head off, ahead, east of Ulva Ferry, is an obvious little hill:


Its a pair of volcanic plugs, called Dun Mor. Really quite obvious. There are quite a few volcanic plugs in the Mull and Morvern area, and they have been extensively studied. This paper by Andrew Kerr gives a lot of information. Abstract here:


So that was todays lunch stop. Eas Fors Waterfall. Of course "Eas" is Gaelic for waterfall. "Fors" is Norse for waterfall and "Waterfall" is English for waterfall.....:)


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