THAMES: 12) The Gap in the Chalk

A hundred million years ago, England didn’t exist.

 

Nor for all but the latest sliver of the ninety-nine million years that followed, for that matter.

 

What about the land they now called England? That existed, in a manner of speaking. But it had no humans yet, and so no names based on imaginary lines on maps or in minds. It also sat about in tropical latitudes some thousand miles from where it is now. It had dinosaurs. When it wasn’t underwater – which much of the time it was.

 

And while it was underwater, it had something else: extremely tiny planktons which, when they died, left behind extremely tiny calcium carbonate shells. There were a lot of them. More than forty million years’ worth in fact. And that’s why these extremely tiny creatures are among the most extremely important things to the people of what is now southern England.

 

They’re standing on them.

  

This stuff. Chalk.

Standing on them physically, but also mentally. The English like standing on these planktons’ contributions. It makes them feel English. Be it rolling downs like the Chiltern Hills or the soaring cliffs of Dover and Beachy Head, chalk is a nigh-obligatory feature in the green-and-pleasant landscapes of their national imagination.

 

The low ridge of the Chilterns, gliding down to the gap where the river runs through the chalk.

The cliffs are ironic. Within that imagination their chalk is a barrier, a natural wall against the inferior barbarian hordes on the European mainland. In reality the chalk does the opposite. Its province of deposits does not separate but connects England, France, Belgium and the Netherlands over a timespan for much of which the island of Britain was no island at all but a European peninsula. The Dover cliffs are not a wall, but a bridge beneath the Channel to the Alabaster Coast of Normandy. It’s the same chalk.

 

Chalk – that is the concern of today’s length of river. It is through the outer arms of this Cretaceous (literally, chalky) realm that the river cuts down to Reading and the comparatively recent sands and clays of the London Basin. And having followed the water up that basin, it is time to cross into a more ancient land: the Jurassic reaches of Oxford, and in their midst, the river’s origins in Cotswold limestone.

 

The view upstream from the Pangbourne-Whitchurch toll bridge, from where we set out today.

The river created this passage itself. Later it would prove important to the human immigrants by funnelling their boats, roads and railways through its narrow corridor. And so the corridor sprouted a pair of villages: Goring on one side, Streatley on the other. From the former comes their present name for this gap in the chalk: the Goring Gap.

 

The river a little downstream of the Goring Gap. For all the chalk’s geological significance you can only draw it out so far for dramatic effect because its hills aren’t actually all that high. There’ll be no breathtaking scenes of the Thames gushing through precipitous canyons. There’ll be plenty of grass though. And cows.

 

Start: Whitchurch Bridge (nearest station: Pangbourne)

End: Goring Bridge (nearest station: Goring and Streatley)

Length: 6.4km/4 miles

Location: Oxfordshire – South Oxfordshire

 

Topics: Whitchurch, Hartslock Wood, Gatehampton, Goring, and the geology of the Thames

 

THAMES: 11) Middle Margins

Today is more or less this.

 

After the town at the centre of things, we come to an in-betweeny space where not much seems to happen. There are fields. Ducks. Overhead cables. It’s quiet back here.

 

Geese on the banks of Rivermead Park, West Reading.

The river near Pangbourne. Railways, pylons and other infrastructure crisscross this backstage space for Reading and its surrounding settlements.

And yet, Reading’s upstream outskirts herald a significant transition in the course of the river.

 

The central Thames thus far has been a procession of castles and palaces, mansions and monasteries, elite schools and sports facilities and sprawling land-grabs by the monied obscene. The Privilege Forts of the English south line up along their valley of imagination: a furnace-belt of willows and glistening water, insulated from its country’s sordid realities by its fortress-walls of inherited wealth as it roars in the manufacture of narratives of high-caste white Englishness.

 

As we have seen, the hammering from these foundries is loud and relentless. Theirs are the stories they want the whole nation to hear.

 

And then, on the far side of Reading – they fade.

 

The upper-middle Thames dispenses with the battlements, searchlights and megaphones. In their place unfurl rolling lowlands, spread with farms and dotted with small villages through which the river comes gliding. Some of these settlements are historic, ancient even, while their surroundings continue to supply the green-and-pleasant backdrop to the English national reverie. Yet now the volume is dialled right down. These settlements merely speak their stories, rather than shout them – except, of course, for one of the loftiest Privilege Forts of all, which waits at the end of this sequence in a certain city known as Oxford.

 

But there is a more important transition beneath that. Literally.

Oxford sits in a basin whose clay is geologically distinct from that of the lower valley. To push north on this island is as to delve deeper in time. Where London’s surface clay is young – that is, Cenozoic, about 50 million years old – Oxford’s goes back some 100 million years further to the Late Jurassic period. And through the space and time in between runs an outer arm of the great network of Late Cretaceous chalk deposits (from c.65-95 million years ago) which stretch across southern England and northwest Europe – and whose separation, of course, is wholly imaginary.

 

One segment of that arm is well familiar by now. The chalk ridge of the Chiltern Hills has overlooked the north bank all the way from Marlow.

This chalk has dramatically reshaped both the landscape itself and its imagery in English culture, and among those effects have been significant changes to the river’s course. There was a time the Thames pushed straight east into the North Sea. But finding its way blocked during the glaciations of the most recent ice age, it cut a gap through the relatively permeable chalk and has since skewed down through the London Basin instead.

 

It is through this gap that we now pursue it, with a better look at this realest of deep-history in the next section. For today the goal is the foot of that gap, where the river emerges between the villages of Pangbourne and Whitchurch.

 

Thames Water HQ, with its sinister spiral stairs in transparent tubes, hulks over the river at Reading Bridge where today’s progress begins.

 

Start: Reading Bridge (nearest station: Reading)

End: Whitchurch Bridge (nearest station: Pangbourne)

Length: 11.2km/7 miles

Location: Oxfordshire – South Oxfordshire; Berkshire – Borough of Reading, West Berkshire District

 

Topics: West Reading suburbs, Purley, Pangbourne – shifting satellite settlements on the edge-of-centre