Saturday, 27 August 2011

I've moved to

I've lost a hyphen but gained a nice new blog, your source for postings on interesting geological things.
Please come on over.
My first post is a sexy blend of Geological reminiscence and innuendo, with added cummingtonite.

Wednesday, 26 January 2011

Where on Google Earth #258

With WoGE #257 Reynardo kindly picked a lovely spot where I went on holiday in 2009, Lyme Regis in Dorset, England.

I've selected an area where you have to travel a bit further to get a decent cream tea...

North is up, Schott rule applies; Happy Hunting!

PS, want to view some of my non-WoGE blogging?

Historic Geological Maps: WoGE #210 revisited

It seems that Irish Geological mapping is available in the same way as the British mapping, but my quick study of their website hasn't found an easy way to show it in Google Earth.

However I've found a nice resource: historical Geological maps of Ireland. A nice website provides a way of viewing both historic maps and memoirs. They are mostly 19th Century, when Ireland was part of the British Empire. The maps themselves seem to be hosted by the British Geological Survey as I guess they didn't hand them over to the new Irish state in the 1920's.

These seem to be a great resource for historians of Geology and also of Empire. The very way Irish place names on maps are spelt reflects the fact that English speaking outsiders were making the maps, garbling the local Gaelic names in the process. I plan to write a bit more about modern attempts to right this in a future post.

I have a very trivial use for these historic maps, which is to show a Geological map view of WoGE #210.

This makes me smile every time. The point of Geological maps is to show the detailed pattern of different rock types, with a kaleidoscope of different colours. The point of the Aran Isles is that there is one rock type that has barely moved since it was laid down, so there is one colour and very little to say. My theory is that the dip measurements were only added to prove that the guy making the map had actually been there and not just mapped it from the mainland, using binoculars.

Just to show that there has been progress in the last 100 years, I've put in a screen-shot from the current Irish Geological Survey's mapping. There are now two colours on the map of the Aran Isles.

Wednesday, 29 December 2010

High definition Geological maps: where on Google Earth #223 revisited

I was very interested to discover that the British Geological Survey has made its superb maps publically available at the 1:50k scale. I know much less than I ought about the technicalities of all this, but I have found a link here which shows the data in Google Earth. I've edited it a little but it basically works out of the box. Obviously it only shows data from Britain...

One obvious omission is a key. Now I know the paper maps well enough to get meaning out of the images, but not all of you are so fortunate. Can anyone more knowledgeable than me tell me how to display the map key in Google Earth?

So, how better to show what I am going on about than to show you the WoGE images from Britain alongside their Geological maps?

WoGE #223 showed a syncline in Carboniferous sandstones/shales alongside obvious quarries in white limestone. The pattern is very clear in the map:

Monday, 29 November 2010

Where on Google Earth #229

I was lucky enough that Felix posted his hint (WoGE #228) just before my lunch-hour, which stopped my futile search for diamond mines (don't ask me why).

Find the location of the picture on GoogleEarth (latitude/longitude) and describe the geology of the place (I have a particular feature in mind). There is no Schott rule, as I think it may be hard to find, but I'm prepared to be proved wrong...

If you do not know what this is all about read this.

Felix has won!
My take on the Geology below.

The ghostly wiggly lines are called roddons (see Wikipedia entry). They are indeed silt/mud surrounded by darker peat and represent an old (but not very old) set of drainage channels over the area.

Since they were formed, the area has been drained (hence the regular shaped fields and drainage ditches). Through a process of drying out and other things the peat has shrunk but the silt channels have not. This means they remain as raised areas and are sometimes the site of villages or roads. The whole area is now below sea-level.

Note the regular fields: these areas were 'enclosed' c. 0.3ka which forms a landscape more like the Netherlands than the rest of England. Also note that the range of photos in the bottom left don't show them; they are subtle features not visible under a healthy crop of vegetation.

A final whimsical note, a less interesting section in Wikipedia debates whether roddon should be spelt rodham, which is the US Secretary of State's middle name (or is it maiden name?). Given her daughter has the same name as a part of London, I wonder if there is a traditional of geographical names in her family.

Sunday, 14 November 2010

Where on Google Earth #223

By way of a contrast with WoGE 222, which was a fine and detailed view of a desert, I've produced a wide view of a reasonably rainy place.

Find the spot on GoogleEarth (latitude/longitude) and describe the geology.

I really don't think this will be hard, so the Schott rule is definitely in place, if you've never won before, now is your chance. If you've won before, wait an hour for each solution before you can post.

Tuesday, 20 July 2010

Where On Google Earth 210

I thought I would create a blog to host this rather than impose on Lost Geologist. I invoke the Schott Rule (former winners have to wait until posting for 1 hour for each WoGE they got right) but things seem rather slow at the moment, perhaps you are all in the field.
As a hint, the islands in the image are in salt water, so that is only 356,000km of coastline to check ;->

The rules of Where on Google Earth are that to win you post in a comment the location of the image, together with some information on its geological interest. The prize is the right to produce the next one.