Posts Tagged ‘scotland’

sandstone, jack hills, western australia, zircon, bruce watson, mark harrison, oldest

These are the sandstone rocks in Jack Hills in Western Australia, in which zircon crystals found by geochemists Bruce Watson and Mark Harrison in 2005, were later dated as being 4.4 billion years old, the oldest material so far found on Earth.

There was a news item on the BBC website a few days ago that tiny crystals of zircon, a blue semi-precious stone, that had been found in a much younger sandstone in the Jack Hills in the Murchison river basin in Western Australia, were the oldest fragments of the earth’s crust. The age of the crystal, which was dated using the decay of trace uranium atoms within it, is 4.4 billion years, only 200 million years after the formation of the earth itself. This is in the very earliest part of the Pre-Cambrian era that makes up seven-eighths of geologic time. The significance of this discovery is not so much how old the rock was, but that it is evidence of the earth having had a solid crust much earlier than had been thought and consequently of having been able to host life very early in its history.

As for the oldest rocks in the world, that is rocks consisting of minerals that have not been subsequently melted or broken down by erosion – unlike the Jack Hills zircon – there are four contenders, depending on the latest research. The rocks are all gneisses (gneiss is pronounced ‘nice’), rocks formed, or metamorphosed, by the action of heat and pressure on earlier rocks. Gneisses are hard, folded, and characterised by darker and lighter coloured bands, and they are widely distributed around the world.

The four locations are in south-western Greenland; the Jack Hills area of Western Australia as above; and in two locations in Canada, the eastern shore of the Hudson Bay and the Canadian shield in the Northwest territory. These rocks have all been dated as being between 3.8 and 4.4 billion years old. The difficulty in assigning the title of oldest to one particular formation of gneiss is that they are all extremely deformed, hence claiming one site to have the oldest rocks may be as much a matter of luck in sampling as by an understanding of the rocks themselves.

geologic time scale, pre-cambrian, age of the earth, jack hills, zircon, chalk, dover, cretaceous

In this geologic time chart, the Pre-Cambrian period, because it covers seven-eighths of the age of the earth occupies most of the lower scale, with the remaining one-eighth expanded into the upper scale. For comparison purposes the Jack Hills zircon were formed in the dark-brown Hadean period at the very beginning of the Pre-cambrian era, and the chalk cliffs of Dover were formed in the light green Cretaceous peiod above, only about 100 million years ago.
Incidentally this is an American chart, and in the UK the two blue periods between the Permian period and the Devonian, are called the Carboniferous period, which is when coal was formed.

But where are the oldest rocks in Britain?

The oldest rocks, the Lewisian gneiss of the Pre-Cambrian era, date from at least 2.7 billion years old – close to two-thirds of the age of the planet – and can be found at the surface in the far north-west of mainland Scotland and on the Hebridean islands. This rock is thought to underlie much of the Britain Isles although boreholes have only penetrated the first few kilometres. The main outcrops of Lewisian gneiss are on the islands of the Outer Hebrides, including Lewis, from which the formation takes its name, but the oldest of these rocks, are on the mainland around Scourie and Laxford Bridge, small villages halfway between Ullapool and Durness.

(more…)

Advertisements

Read Full Post »

furthest point, ruadh stac beag, fisherfield forest, wester ross, scotland

The ‘furthest point’ is in the centre of this map, to the left of Ruadh Stac Beag.
© 2013 Ordnance Survey

What is the furthest point from a tarmaced public road in mainland Britain? There may be other contenders for remoteness, but the Ordnance Survey has determined this point as a peat bog on the western hillside of Ruadh Stac Beag in Wester Ross in Scotland, amongst the burns (‘allt’ in Gaelic) that come from Lochan a Bhraghad. The point is at a height of about 610m (2,000 feet) and the grid reference is NH 0202 7700.

It is 10.43 km (6.48 miles) in a straight line from the nearest road, the A832 near the village of Kinlochewe. But up here in the boggy  mountainous wilderness of the Fisherfield Forest of Wester Ross, that doesn’t mean very much.

furthest point, wester ross, scotland

The ‘furthest point’ is marked by the blue spot in the centre of this map of Wester Ross, Scotland,
© 2013 Ordnance Survey

The shortest distance by a path, where there is one, is from Kinlochewe, the nearest settlement, and it is 24.2 km (15 miles). There are a number of deer-season only hunting lodges and abandoned houses, and an out of season bothy, Shenavall, to the north of the ‘furthest point’ near Loch na Sealga and below An Teallach (1,062m), but that is all. There is a nearer settlement at Letterewe on the side of Loch Maree to the south-east, but that is on a private estate.

There are no photographs of the location as far as I know but the nearest photograph, below right, is of Lochan a’ Bhraghad, a small lochan close by. For what it’s worth, the ‘furthest point’ is about 500m away over the slight hill on the right side of the picture.

lochan a' bhraghad, ruadh stac mor, wester ross, scotland

Lochan a’ Bhraghad north east of Ruadh Stac Mor.
© Stuart Meek/Creative Commons Licence

In 2002, the Daily Telegraph sent one of its reporters, Colin Cottell, to this remote spot. He rang the Ordnance Survey to check before setting out. ‘Less than seven miles? Hardly worth getting out of my sleeping bag for. Or so I imagined’. His report is here.

The Fisherfield Forest, and the Dundonnell Forest to the north, is sometimes nicknamed The Great Wilderness because the area is entirely devoid of permanent settlements. Although termed a forest, the area has very few trees, though it was a pine forest 200 years ago.

fisherfield forest, ruadh stac beag, wester ross, scotland

In the midst of the Fisherfield Forest, this is a view down Gleann na Muice Beag to the north of Ruadh Stac Beag and about 1km from the ‘furthest point’.
© Roger McLachlan/Creative Commons Licence

Three estates cover most of the area which is maintained primarily for deer stalking: Dundonnell Estate covers 134 km² in the northwest part of the forest, the Eilean Darach estate covers 262 km² in the northeast, and majority of the area, including all the southern and central sections, forms the 323 km² Letterewe estate.

Other places of interest in Britain:

Lowest land in Britain

Read Full Post »

PointofViewHe who neglects what is done for what ought to be done sooner effects his ruin than his preservation.’  Machiavelli – The Prince – 1532

In response to the demands of the Scottish Parliament (controlled by the majority Scottish Nationalist Party) the UK Government has agreed to hold a referendum in Scotland on the question of Scotland’s independence from the UK. This is due to be held in 2014. Already the ‘NO’ camp and the ‘YES’ camp have been set up fronted by prominent politicians and personalities to campaign for their case in the lead up to the vote in 2014.

Map of the United Kingdom of Great Britain & Northern Ireland

Map of the United Kingdom of Great Britain & Northern Ireland

However, the debate around Scottish independence has been increasingly bothering me. It’s not that I have strong feelings either way about Scottish independence but it’s the way we’re going about it that bugs me.

Whether we live in England, Scotland, Wales or Northern Ireland, we are all citizens of the United Kingdom, our nation state. As such we all elect our members of parliament from local constituencies throughout the UK and we all travel with UK passports when we venture beyond our island shores. We know that the UK is made up of four distinct nations, three of which have devolved government with their own parliament or assemblies composed of their own elected members, with the exception of England which kind of gets by without any of these legislatures.

Flag of Scotland, also known as the Saltire or the St Andrew's Cross

This road sign on the A1 road near Lamberton marks the border between England and Scotland. The sign’s design comes from the Flag of Scotland or the Saltire, a diagonal white cross on a blue background. The saltire stems from Parliament of Scotland having decreed in 1385 that Scottish soldiers shall wear a white Saint Andrew’s Cross on their person.

This network of governance seems to me to be at least some kind of bond that unites us all as part of the UK. Now I could mention the Crown and the Royal family but really that’s an entirely separate issue of interest and, for me, great concern and I shall leave that for another time.The point that troubles me here is that while I can accept the people of one or more of our existing nations can decide that they would like to break away from the UK and become independent, it surely doesn’t stop there. Don’t we all have a right to have a say on the continuing status and perhaps existence of the UK? Don’t we all have a stake in the sanctity of our nation state?

In my mind there should be a clear process to follow that respects the views of all UK citizens, or at least the majority of them. Simply speaking such a process would look something like this.

Stage 1.  The people of an existing nation and their elected representatives campaign for and get a majority in favour of independence.

Stage 2. A ballot is held of all peoples in the nation concerned to test the degree of support for independence.   If a majority votes in favour then,

(more…)

Read Full Post »