London underground

Dr Richard Ghail, of Imperial College London, and others have discovered that the structure of the London Clay is not the simple syncline it had been pictured as until around 2004 – the maps of the British Geological Survey (BGS) showed hardly any faulting. But evidence of a continental collision some 300 million years ago, the Variscan orogeny, still shows up today as SE–NW ‘strike-slip’ fault patterns in southern Britain, and Dr Ghail’s research has shown that the London Clay is riddled with them; where this creates voids, groundwater can flow through them. In the Lambeth Group of sediments, which lie below the Clay, he has also found that oxygen-hungry iron compounds – a potential hazard for tunnellers.  He’d like to use his research techniques on data from future missions to Venus, a previous focus of his work. (Note: readers are advised to remind themselves of the tune of “The Teddy Bears’ Picnic”.)

If you dig into the London Clay, you’re sure of a big surprise –
If you are tunnelling London Clay, it really would be wise
To tap into the specialist knowledge of Richard Ghail of Imperial College
’Cos, underground, the geology is no picnic.

Every geologist who’s been good is sure of a treat today:
There’s lots of marvellous strike-slip faults in the wonderful London Clay:
Beneath the city it’s not very pretty and water flows where nobody knows,
And that’s because the BGS never mapped it.

Picnic time for Richard G
Is finding unknown faults where everyone thought there weren’t any.
Spot them, plot them on the maps, see how they match Variscan orogeny!
See him gaily gad about, for he is mad about tectonic geology.
At six o’clock his ICL students will write up what he’s said,
Because they all want an MSc!

If you dig into the Lambeth Group, you really should beware –
If you disturb the Lambeth Group, you’d better not breathe the air,
For Doctor Ghail has found green rust eats oxygen; and so you must
Be careful, for it certainly is no picnic.

Picnic time for Richard G
Is Venus, which, it seems, has plate tectonics like Earth’s today.
Watch him, catch him unawares, and see his research getting underway.
See him gaily gad about, for he is mad about Venusian geology.
He’d really like to climb on a rocket and do his work in space –
He’d be an orbiting PhD!

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