Jurassic Lark

1st October 2013 at Waterloo, Broadford Bay, Isle of Skye. This is an area of Jurassic sandstone and we'd come to find fossils. A fossilized dinosaur leg bone has been found here but our sights were set slightly lower.

 These large pink pebbles may be granitic.

 Looking back south westwards towards Broadford, with the granite hills of Beinn na Caillich (right) and Beinn Dearg Bheag in the background. In the foreground is the weathered grey Jurassic sandstone (?).

 More plates of weathered sandstone.

 Looks like a bit of limestone and a seam of yellow mineral.

Limestone at an early stage of formation.

More grey sandstone slabs. There are a very few small grey sand beaches on Skye, so things haven't changed that much in the last 200 million years.

There were quite a few tiny ammonite fossils scattered around.

 And several of these crater like structures.

This cellular pattern; is it lichen?

 Quoting Jo: "Well I have looked at other similar images and to me it does look like a cone from the species of Araucaria. These are trees that form cones. However fossils have only been found in the southern hemisphere, although they are of the Jurassic period, and as this period goes back 200 million years, these rocks could well have been in the southern hemisphere. Maybe I am over interpreting it just a squdge or a squidge!!! We need expert advise. Remember it has been exposed to tremendous pressures over a long period; to remain intact would be rather remarkable and it could well be squashed. It does have seed like indentations around the outer edges and the shape is almost there".

 And there was this segmented, worm-like thing.

 And a rough scallop-shaped entity. 

 The hills to the east exhibit a wiggly surface terrain.

 Back to Broadford.

A cuboid rock enjoying life with the lichen.

Raasay Iron Ore Mine, 8 January 2013

We were on the island of of Raasay on a cold, sombre winter day to look at the remains of an iron ore mine where in the first world war German prisoners worked in a process that would ultimately produce weapons with which their fellow countrymen were killed. This was in contravention of the Hague Convention. At the end of the war many of the prisoners never returned home, having died from infectious diseases. The price of iron ore on the world market slumped and the mine was closed because it was no longer profitable.

Having arrived on the ferry. 

 Looking back to Skye.

The furnaces where crude iron ore was partly enriched before being loaded into a huge storage hopper from where it was shipped.

 Looking along the line of furnaces.

 The support columns marking the line of the small railway along which the crude ore was transported from the mine to the furnaces.

The remains of a mining building.

This may be the closest we got to the actual ore seam. We weren't sure what it was.

A quick sandwich and coffee before rushing back for the final daylight ferry.

The Moine Thrust

2 October 2012

 

The A890 south of Achmore apparently traverses the Moine Thrust which is exposed in a cutting through a small hill. The rock is largely made up of Moine Schists which were formed metamorphically from sedimentary rocks when the Iapetus Ocean closed as the continental land masses Laurentia (North America), Avalonia (Europe), and Baltica collided, with Scotland being on the front line of this massive coming together. Following the heat, pressure, and folding, the rocks recrystallized as thin sheets (foliation or schistosity). Schists are said to comprise platy minerals such as mica, chlorite, amphibole, and talc.

 

Here's a section of the exposed rock. If you look closely you will see the fine sheet-like layers.

 

 

Notice too how although the bulk of the rock appears a shiny grey, typical of mica schist, there are also areas in which the predominant colour is pale green which maybe indicates the presence of more chlorite schist. There is also a seam of some quartz-like mineral cutting through the schist.

 

 

 

 

 

A rather interesting bright red mineral seeping through pores in the rock, or a recent murder scene.

 

 

A band of iron mineral-containing rock.

 

 

I wonder if some of this reddish stuff is garnet-mica schist.

 

 

 

 

 

A bunch of local chavs on there way to a hidden dell with their bags of bucky, cheap cider, and various assorted solvents.

 

 

 

 

 

 

 

 

 

 

 

Interesting!

 

 

Looking back south towards Loch Alsh.

 

 

Lunch at Plockton

 

 

All geological assertions in this blog must be taken with half a teaspoon of smoked paprika.