scotland – Coastally Curious

Sand: Barra, Scotland

A few weeks ago, I shared some sand that my dad brought back from the Butt of Lewis. On that same trip, he and my mom went to visit the island of Barra, where her family originated from before emigrating to eastern Canada in the 1770s.

Halfway through their holiday, I received an excited text message from my dad: “Tell me – the whole island seems like grey granite, so where does the white sand come from? (In fact all the west side beaches are white sand.) Is it coral?”

Eager for a distraction from my work, I did a quick lit review. The consensus seems that indeed, the white sand on the beaches has almost nothing to do with the gneiss found on the rest of the island. In essence, it seems as though most of the original sand was bulldozed there by glaciers during the last ice age or brought there by meltwater as they retreated. Then over the course of the past few thousand years, shell fragments have accumulated and overwhelmed the native glacial sand, making up 7.5% to 82.9% of the total sand. This results in the beautiful white beaches that you see today (Jehu & Craig, 1924; Goodenough & Merritt, 2007).

This might be my favourite sample of sand that I have analyzed yet- it is incredibly shelly, and every photo reveals beautiful new shapes and patterns. I think I will just let the sand speak for itself:

BarraHotel_000018 — When you zoom out, it doesn’t look like much…

BarraHotel_000000 — …but zooming in reveals all sorts of interesting shell fragments with different structures and colours.

BarraHotel_000002 — I particularly love the piece in the middle of this photo: it almost looks like a piece of glazed pottery.

I love the spiral shells. Last summer I read a really cool book about the evolution of mollusks and seashells: Spirals in Time: The Secret Life and Curious Afterlife of Seashells. Worth a read if you like this sort of thing!

BarraHotel_000005 — I’m really quite curious as to what the red and white fragment in the upper left quadrant is. It looks like a piece of octopus tentacle, although I know it can’t be!

BarraHotel_000007 — Purple is my favourite colour, so I love the shade of the fragment in the lower left corner. It actually looks a lot like the coralline algae we saw in my photographs of sand from Archipel Glenans. I wonder if something similar is present offshore of Barra… The cylindrical fragment on the right side makes me think of a Roman column.

BarraHotel_000012 — This one might be favourite- I zoomed in to 40x magnification to take a closer look. The patterns of the white bubbles are beautiful- I am very curious whether that is a shell fragment or actually some sort of igneous rock left over from Scotland’s volcanic days…

BarraHotel_000017 — I love the iridescence of the shell at mid-right, and the vivid pink streak in the top left quadrant. So many cool shapes and colours!

I hope you enjoyed those as much as I did. I just wish I knew more about ecology so that I had a better idea of what we were actually seeing here!

Sources:

Goodenough, K., & Merritt, J. (2007). The Outer Hebrides: a landscape fashioned by geology. Scottish Natural Heritage.

Jehu, T., & Craig, R. (1924). XXII.—Geology of the Outer Hebrides. Part I.—The Barra Isles. Transactions of the Royal Society of Edinburgh, 53(2), 419-441.

Sand: Ardrossan, Scotland

I recently paid a visit to my grandmother in Glasgow, Scotland. She is 94 1/2 years old and is still a delight to be with. Since she is living in a retirement home now and doesn’t get out much these days, I rented a car and we went for a drive together down the coast to Troon:

On our way back to Glasgow I pulled over the car in Ardrossan and grabbed a handful of sand from the beach there:

Sand from the beach at Ardrossan, Scotland. It appears to be fine, well-rounded quartz sand. Note the beautiful red tint of the grains.

When I showed my dad this photo, he pointed out that the pink sand grains resembled the red sandstones found in houses and buildings all across Glasgow, the city where he grew up. When I looked into it further, it seems that many of the sandstone bricks used in facades across the city indeed came from Ayrshire, where this beach was located. This is backed up by a geological map of the Firth of Clyde, which shows our little beach comfortably inside the red sandstone zone. A delightful convergence of sediment and architecture!

Scotland A 038.jpg — The Kelvingrove Gallery, one of my favourite places in Glasgow. If you ever find yourself in Glasgow I highly recommend it- it’s free! Note the beautiful red sandstone facade.

That’s one of my favourite things about this field- there always seems to be new and interesting connections back to other things that I love!

Scotland C 055.jpg — Majestic highland cows in Pollock County Park, Glasgow. Note their beautiful red sandstone facades.

Sources:

Jardine, W. G. (1986). The geological and geomorphological setting of the estuary and Firth of Clyde. Proceedings of the Royal Society of Edinburgh, Section B: Biological Sciences, 90, 25-41.

Sand: The Butt of Lewis, Scotland

This week our sand comes from the delightfully-named Butt of Lewis, the northernmost point of the Isle of Lewis. Lewis is part of the Outer Hebrides, an archipelago off the west coast of Scotland. My parents visited there this summer as part of a trip to Barra, a neighbouring island and the ancestral home of my mom’s family. My dad brought back a little bag of sand from the beach at Ness:

A beautiful mix of what appears to be mainly carbonate sand from shells and what I presume to be material eroded from the abundant gneiss and glacial deposits on the island.

The most important question here is obviously not about the sand though, but rather, why they called this place the “Butt of Lewis”. After half an hour of creative and persistent googling, I couldn’t find anything, though. My guess is just that it’s because it’s at the very back end of the island. But also quite windy?