49 – The Problem with Chalk and Flint
Whilst the rest of the Coastal Clan battled with a virus, I went back down to the south coast to meet Mark, our friend and Guest Walker. We had been trying to get together to walk over Beachy Head and the Seven Sisters for weeks. Our diaries finally coincided. The main Coastal Clan had in fact already completed this stretch, but their being ill presented a good opportunity for me to revisit.
Mark and I parked in Birling Gap and set off. It was a little bit bracing.
At the end of the Sisters we dropped down into Cuckmere Haven, circling round on ourselves to see the cliffs. The cliff faces are chiefly noticeable for the fact that they are big and white, but in fact they are worth a closer look. They took millions of years to form, but are now at the end of their life. Soon they will fall into the sea. Surely, therefore, they are deserving of a few minutes of time.
They have thin dark lines in them, running horizontally across their faces.
These dark lines are flint. Whilst the chalk in the cliffs was made from the calcium-rich skeletons of trillions of plankton, called coccoliths, the flint is different. It is not calcium-rich at all, but formed primarily from silica. It comes from quite a different source altogether.
The flint deposits here are believed to have come from marine sponges, as well as from silica-rich plankton called diatoms and radiolarians. As plankton with calcium-rich skeletons died and literally rained down onto the seabed, forming a white ooze of sediment, they were joined by these marine sponges and silica-rich material. The silica then formed into pockets of ooze within the ooze, eventually dehydrating and hardening into quartz crystals that form the flint.
The question, though, is why the silica concentrated in the way it did, forming flint “nodules”. The answer to that question is that nobody really knows. What is known is that the formation occurs during diagenesis, the name given to the process during which rock forms from sediment. During diagenesis the silica is mobile enough to concentrate. Perhaps is concentrates in a burrow in the ooze, made by a another animal. Nobody knows for sure.
The chalk and flint was formed here during the Late Cretaceous Period, 60-90 million years ago. How many years, therefore, might have passed between each flint band in this chalk?
These bands are known as “flint horizons”. If the flint was formed by silica concentrating around burrows, then this would suggest that there was a pause in chalk deposition, because for an animal to burrow into the ground, and indeed leave a burrow in tact, some form of earthy base must have formed. Then, later, the silica would have had time to penetrate the burrows and concentrate enough to form the flint.
This is not the only theory. One alternative theory (by way of illustration) is that the Milankovitch Cycle is to blame. Milankovitch Theory deals with the oscillating changes in the orbital cycle of the Earth (stick with me here). It is measured in thousands of years, and affects climatic patterns. Every 20,000 years, for example, the rotational axis of the Earth changes. Would that, then, account for a change in the way sediment settles and allow flint horizons to form? One problem with this is that Milankovitch Cycles are driven by changes to the Earth’s ice volume, and during the Cretaceous Period there were no ice caps at either pole.
Hmmmmm.
So what could it be? Were there pauses in the precipitation of calcium-rich coccoliths to allow siliceous planktonic micro-organisms to concentrate during diagenesis? Or did Milankovitch oscillations in axial tilt determine climatic changes by orbital forcing, thereby causing layers in the upper-chalk formations of the Late Cretaceous Period?
The best thing, I find, is to have a whisky and look at the pretty patterns in the cliffs.
Points on this part of the walk (copy and paste the co-ordinates into Google Earth):
- The Cliffs at Cuckmere Haven: N 50° 45.430 E 000° 09.330
Walk #49 Statistics:
- Date of Walk: 14 April 2013
- Walk #49 total distance covered: 11.16 miles
- Coast of Britain Walk Total Distance Covered: 401.83 miles
- CLICK HERE FOR LINK TO INTERACTIVE MAP!!!
The Coastal Path in Paris – The Louvre
We were in Paris for just over two days. You can’t do Paris in two days.
We spent about three hours at the Louvre. You can’t do the Louvre in three hours. In fact, you can’t really do the Louvre in two days. Perhaps you could do it in two weeks. It is immense. The entrance pyramid pokes up out of the ground like the tip of an iceberg, hiding a huge complex below. Down you go, only to surface in various wings. All of the buildings in this photo are part of the Louvre.
Our children wanted to see the Mona Lisa. We headed off, through the vast halls and passages. We were watched by the sacrifice, suffering, martyrdom and murder of hundreds of years we sped through, barely giving anything a second glance. I felt a deep-pitted guilt in my stomach, as I always do when visiting an art gallery. There is simply not enough time to give every painting the time it deserves. The gallery halls were absolutely vast and some seemed to be never-ending. One, I estimated, was a quarter of a mile in length.
As we passed through rooms we sometimes stopped in our tracks. The ceilings were absolutely stunning.
Eventually, we got to our destination. There she was: the Mona Lisa. I thought we would have to queue to see her, but there are no queues. The kids pushed to the front of the throng of people and stared at the painting from behind a rope, set back by a couple of meters. Space enough to see her, but not enough to get to really know her.
As well as introducing ourselves to the Mona Lisa, we said hello to the Venus de Milo and Lady Macbeth. Saints saved their last looks for us as they died; children cried out in horror as their fathers were slaughtered by soldiers. Frontiersmen defended themselves from wild wolves, and the cold blue ice of Scandinavian landscapes was braved by explorers. We could have spent days in this one place (we nearly did, getting lost looking for the Egyptian exhibits), but a two day city break allows for little more than a taster.
The Louvre sits on the north bank of the Seine. We caught the Batobus back to our hotel.
Location of the Louvre (copy and paste the co-ordinates into Google Earth): N 48° 51.660 E 002° 20.150
The Coastal Path in Paris – Walking
We walked wherever we could in Paris, although we also used the wonderful Metro and RER trains. On our second day, we left our hotel and stopped at the Statue of Liberty – a smaller replica of the statue in New York Harbour. It is a quarter of the size of the original and stands at the southern end of the Île aux Cygnes, an island on the Seine. The statue stands next to a bridge crossing the island. I couldn’t help notice the irony that homeless people were living under this bridge, right next to this quarter-sized symbol of freedom.
We crossed the river to the right bank, and walked up to the Flamme de la Liberté, a full sized replica of the torch carried by the New York Statue of Liberty. It was placed here in 1987 to celebrate 100 years of the International Herald Tribune, but is now more associated with the death of Diana, Princess of Wales. It sits at one end of the tunnel where she died. There were photographs, flowers and messages at the site.
We cut away from the Seine at this point and headed over to the Arc de Triomphe, although one of our party was feeling a little tired and needed a Parisian foot massage on the way.
This provided energy enough to make it to a cafe for lunch. We walked off the tourist track, stopping at a cafe I don’t know where. We had to converse in French. We ate with workmen; locals; anyone but tourists. It felt good – as if we were seeing some of the real Paris and not just the tourist gloss. We paid our bill, left and worked our way up to the Arc de Triomphe. Our intention was then to walk over to Sacré Coeur, a distance of only two to three miles or so, but time was getting on and feet were getting tired again, so we took the Metro. Sacré Coeur was busy, and the smog was back, impeding the views which might otherwise be afforded from its dome.
We decided not to enter, but instead went to the Place du Tertre, just to the west. Portrait painters and caricature artists tried to sell us their services with varying degrees of politeness. Most were friendly and pleasant. One was not. “What’s your problem? Time or money?” he asked. The way he asked it conveyed an absolute certainty that he was going to have a smart response to whichever answer we gave. In fact, our problem was neither time nor money. It was him (but I didn’t tell him that). We ended up getting a coffee and watching people sit for their portraits. Perhaps it was a bad day, but none of the portraits looked very much like their subjects. One particular artist seemed to be sketching Scarlett Johansson. His poor subject (who looked nothing like her) sat patiently, blind to what was being sketched out and waiting for her likeness to be revealed.
We left before the grand unveiling. To this day I wonder what she thought, and whether the painting now hangs on her wall. If you ever happen to be bidding on eBay for an original picture of Scarlett Johansson, cancel your bid if the picture shows her wearing a green scarf and the artist has a French looking name. It’s not her. Trust me.
Points on this walk (copy and paste the co-ordinates into Google Earth):
- Statue of Liberty: N 48° 51.001 E 002° 16.782
- Flamme de la Liberté: N 48° 51.851 E 002° 18.053
- Arc de Triomphe: N 48° 52.429 E 002° 17.700
- Sacré Coeur: N 48° 53.199 E 002° 20.584
- Place du Tertre: N 48° 53.193 E 002° 20.450
The Coastal Path in Paris – The Arc de Triomphe
I wasn’t sure what to expect from the Arc de Triomphe. We could see it from the Eiffel Tower on our first day. More than anything else it looked rather large, dwarfing the buildings around it. There is quite a lot in Paris that looks rather large.
The Arc de Triomphe was commissioned in 1806. It took some 30 years to complete. It stands as a monument to those who fought and died for France during the Napoleonic Wars. The names of generals and military victories are inscribed on its walls.
We walked up the right bank of the Seine to get there. At one point a man walking in front of us stooped down and picked up a gold ring he saw lying on the pavement. He looked at us in a strange way as we walked on. About 100 yards later another man walking towards us suddenly stooped down - wow! Another gold ring lying on the pavement! This man tried to engage us in conversation about it. I tried to disengage us, astonished that two separate con artists would try to scam us with the same trick within the space of 100 yards. Were these people completely stupid? No, I realised, it is the tourists who are completely stupid, and clearly tricking them is big business here. This was not, by any means, the last we would see of the Parisian scammers.
As well as being quite large, the Arc de Triomphe is also rather grand. There is quite a lot in Paris that looks rather grand.
The building is well known for its friezes. Ornately sculpted figures gazed down at us as we circled round.
Underneath it lies the Tomb of the Unknown Soldier, interred here in 1921.
It is possible to climb up to the roof of the Arc de Triomphe. The queue was short and the views were as good as they were from the Eiffel Tower. Twelve main roads all converge at the Arc de Triomphe. They radiated away from our vantage point, giving us a fantastic perspective that cannot be enjoyed from elsewhere.
Location of the Arc de Triomphe (copy and paste the co-ordinates into Google Earth): N 48° 52.429 E 002° 17.700
The Coastal Path in Paris – The Eiffel Tower
“What? You’ve never been to Paris?” asked our incredulous friends. We were tired of hearing this. There was only one thing for it - a Eurostar booking later and we were on our way. I suppose it is only natural that during our first trip we were out-and-out tourists, visiting only picture-postcard places. First stop was the Eiffel Tower. It dominates the Paris skyline from pretty much everywhere. It is an iconic symbol, instantaneously recognised all around the world. Yet although we had seen it on screen and paper a thousand times, the real thing still held a certain amazement.
We arrived in the afternoon, dumped our bags at the hotel and walked straight there. We stood underneath and marvelled at its sheer structural scale.
We queued up for about 45 minutes, buying our tickets to walk up to the second level. From here it is possible to get a lift up to the very top, but we were told there was a further 45 minute wait. It was already late in the day and we decided against it. As we walked up we realised just how much metal has gone into the Tower’s construction.
As we climbed the steps, metal lifts whirred up and down metal rails, pulled by metal cables which were powered by metal wheels. Metal spotlights watched the proceedings.
Lift after lift went up and down.
We got up to the second level. Despite the haze, there were impressive views from all sides.
The Champ de Mars to the southeast…
To our north the Arc de Triomphe stood fighting for breath against the smog.
At the second level the wait was not, in fact, anything like 45 minutes. It was more like five to ten. We wondered if there was anywhere to buy tickets to get to the top, but there was not. What had once been a ticket office was boarded up. We could either go back down and queue up again, or accept that on this trip we would not reach the top. We accepted it was not to be. All we could do was look up to the pinnacle and wonder what its views would be like.
We went back down and straight into a bistro we had seen earlier. After a very good meal served by a very friendly waiter, we left. Night had fallen. The Eiffel Tower was lit up, with a revolving light shining piercing beams from the very top.
It just so happened that we left the bistro a few minutes before 8 o’clock. We did not realise it, but we were in for a treat. Precisely on the hour we heard some excited cheering coming from the balcony of a nearby building. We turned, and there was the Eiffel Tower, covered in a shower of twinkling white lights. What a spectacular display! Apparently this only lasts a few minutes each hour, but it is truly worth positioning yourself for the occasion. We went back to the hotel very happy with our first day of Parisian tourism.
Location of The Eiffel Tower (copy and paste the co-ordinates into Google Earth): N 48° 51.500 E 002° 17.680
48f – Hope Gap to Seaford
We walked away from Hope Gap, up the ice age valley and onto the cliffs that would take us over to Seaford. Ahead of us and slightly inland, we saw a strange looking structure. What was it? The map told us we were walking next to a golf course. Was it some new-fangled driving range?
In fact this was some VOR Air Traffic Control radio equipment. This modern piece of equipment was sat right next to the walls of an ancient Iron Age fort. These walls are now little more than earth-covered mounds, but they are marked on the map and easy to spot if you look out for them. This fort was originally quite a way inland, but coastal erosion now means that the cliffs have caught up with it. Half of it has fallen into the sea.
Over the cliffs we went, and then down the approach to Seaford. There were some interesting furrows in the grass here. They were mini striations, guiding us into the town.
We carried on. At one point, just as we descended into the town itself, we witnessed a sombre ceremony, as three people quietly turned a container into the wind and scattered the ashes of a loved one. We turned and took one last look back to the cliffs, then carried on forward and down into the car park at the eastern extremity of the town.
Points on this part of the walk (copy and paste the co-ordinates into Google Earth):
- VOR Air Traffic Control Radio Equipment: N 50° 45.640 E 000° 07.315
- Iron Age Fort East Wall: N 50° 45.600 E 000° 07.195
- Iron Age Fort West Wall: N 50° 45.680 E 000° 06.955
- Furrows in the Grass: N 50° 45.703 E 000° 06.890
- Seaford Car Park: N 50° 45.885 E 000° 06.495
Walk #48 Statistics (of which this post forms the last part):
- Date of Walk: 1 April 2013
- Walk #48 total distance covered: 7.82 miles
- Coast of Britain Walk Total Distance Covered: 390.67 miles
- CLICK HERE FOR LINK TO INTERACTIVE MAP!!!
48e – Exceat Bridge to Hope Gap
Once we crossed Exceat Bridge, we walked down the west bank of the Cuckmere River and back to the coast. At the mouth of the river we passed the Coastguard Cottages. In a field just behind them stands a lonely memorial. It remembers an unknown number of Canadian soldiers who died here in 1940. The Canadians had arrived in the Cuckmere Valley and pitched their tents in this field. Although they were warned by locals that the Germans flew over frequently, using the valley for navigation purposes, they ignored these warnings. The Messerschmitts came two days later. They flew up the valley, sptted the encampment, and so banked hard and flew back down again, raking the tents with fire and dropping their bombs. All of the men billeted in the tents were killed. The commanding officer who had ignored the warnings of the locals was shaving in one of the cottages. He was killed instantly when a shell went through the wall on which his mirror was fixed.
As we left the field and started making our way up the cliffs, a fishing vessel came into view. A sole fisherman was at work, kept company by a flock of gulls, obviously hoping to share his catch.
We carried on, reaching Hope Gap. Like the Seven Sisters, Hope Gap is a valley which was formed in the last ice age. Its steep banks have been sheared by coastal erosion, leaving a dramatic edge to them.
At Hope Gap it is possible to go down a set of steps onto the chalk platform and rocks below. From here there is a good view back to the Seven Sisters (not all of them are quite in view). The brown coloured substance at the top of the small cliff in the foreground is loess, soil which was blown here by the Arctic winds of the ice ages.
The walk up the valley at Hope Gap was stunning. Again and again we would turn back to gaze at the Seven Sisters.
Points on this part of the walk (copy and paste the co-ordinates into Google Earth):
- Exceat Bridge: N 50° 46.424 E 000° 08.770
- Cuckmere Valley Memorial: N 50° 45.565 E 000° 08.667
- Hope Gap: N 50° 45.385 E 000° 08.340
Walk #48 Statistics (of which this post forms the fifth part):
- Date of Walk: 1 April 2013
- Walk #48 total distance covered: 7.82 miles
- Coast of Britain Walk Total Distance Covered: 390.67 miles
- CLICK HERE FOR LINK TO INTERACTIVE MAP!!!
