Tuesday 31 May 2016

Loess in Britain II Airport Story

Once upon a time there was a plan to build a great airport in the Thames estuary. This was to be the main London airport, replacing rather than supplementing Heathrow LHR. This was to be the only airport built on loess(?) -that is a disputable statement for several reasons; there might be other loess grounded airports (in Timaru maybe) and in fact the proposed airport was only partially on loess ground. A lot of other geotechnically challenging sediments were involved. But it was to be the biggest project in Britain to involve loess (if one ignores the centuries of exploitation of the loess deposits nearby for the purposes of brick manufacture).
All this was happening in the 1970s and the project was soon cancelled: too expensive, too ambitious, too radical, it was a very un-British project- full of style and brio and imagination and foresight; it was quickly cancelled- but not before the British Geological Survey had been deployed to do a careful study of the region. This produced the best and most thorough study of loess in Britain- which was eventually published:

Northmore, K.J., Bell, F.G., Culshaw, M.G.  1996.  The engineering properties and behaviour of the brickearth of south Essex.  Quarterly Journal of Engineering Geology 29, 147-161.

It took 20 years for the material to be published (quite quick by BGS standards). The initial work was largely done by young, recently graduated engineering geology MSc students from the University of Leeds. They worked well and enthusiastically as young geologists, and as grizzled veterans saw their great works published. In this study thicknesses of loess of up to 8m were reported which makes south Essex an interesting loess region. Of course in the early 2000s the plan was resurrected, and(for the reasons cited above) will be rejected. Actually there is loess material involved at the Heathrow site- as will be discussed later in the 'Loess in Britain' blog sequence.



 

Saturday 28 May 2016

Loess in Britain I

If you search Google for 'Loess in Britain' the response is not great- the first entry is Lill & Smalley 1978, and this appears as entries 3 & 4 as well. It seems strange that this could to be the most significant paper on loess in Britain, there must have been some loess research in the last 40 years.

Lill, G.O., Smalley, I.J.   1978.  Distribution of loess in Britain.  Proceedings of the Geologists Association 89, 57-65

Actually entry no.2 is a bit more up to date, the Jefferson et al 2003 paper in Mercian Geologist; and this paper contains a good idea, a way of approaching the study of loess in southern Britain. We assume that loess material arrives in Britain from the east and spreads across the southern counties as a thin deposit. We are on the edge of the action so it is a thin deposit. After deposition this material is moved about and eventually forms a series of small deposits..

Jefferson, I., Smalley, I.J., Northmore, K.  2003.  Consequences of a modest loess fall over southern and midland England.  Mercian Geologist 15, 199-208.

 

Tuesday 24 May 2016

Bee-eaters and Loess in Australia

Parts 3 & 4 of the Loess and Bee-eaters story are now available in Quaternary International 399.  The distribution of the rainbow bird in Australia looks like a good example of the birds following the dust.