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Seven intrepid members assembled at the Pickwick Quarry in the Wiltshire village of Corsham. We were met by David Pollard, the owner. David re-opened the quarry in 1999 after it had closed as a tourist attraction (I believe that the Branch visited the quarry at that time). The quarry is now operated under license by the AMEC company. Recently stone from the quarry has been used in the new extension to Buckingham Palace.

David started with a safety briefing and checked we were equipped with torches, hard hats and boots. He then gave us a brief overview of the mine and the underlying geology. All too soon it was time to descend into the darkness.

The actual entrance to the quarry is a steeply sloping adit up which the stone blocks are winched. This is flanked by the 159 steps used by the quarrymen.

Although we visited on a Saturday, the quarry was still being worked, albeit at a reduced level. Nevertheless, two stone cutting machines were in use, plus a fearsome looking articulated loader was roaring around the tunnels.

David, accompanied by his son, led us through the working part of the quarry and explained the process by which the stone is extracted. The mechanics of this method has not changed since the beginning of underground quarrying. A series of horizontal cuts is sawn in the working face, followed by a series of vertical cuts to divide the face into blocks. These blocks are then broken out of the face and hauled away.

The quarry was in production from about 1810 until the 1960's. During the Second World War, the quarry was used to store ammunition. Signs of this occupation can still be seen in the older parts of the quarry. These parts are not being worked but are being maintained for their historical interest. Among other features we saw a wonderful wood and iron stacking crane.

After we had made our way to the surface, David Pollard led us to Box Quarry. This quarry was in use from 1830 until 1960. It has now become the very attractive garden of a private house built on the spoil heap. Originally open cast, the quarry developed extensive underground workings after operations threatened to undermine a road.

After lunch at the "Quarryman's Arms”, it was to time to convey our thanks to David for an extremely interesting day and as it was still early afternoon the group decided to pay a short visit to Avebury to look at the sarsen stones (and to finish with a cream tea!)

At 10 am on Sunday 30th June, eight fugitives from the World Cup Football Final gathered in the car park at Newlands Corner, a high point on the North Downs, near Guildford in Surrey. The purpose of this meeting was to follow the 5 mile (8 km) Trail as detailed in the excellent and highly recommended Surrey RIGS Group booklet, initiated and organised by our leader, Iain Fletcher.This is on sale for just £1.50 at the Newlands Corner Visitor's Centre.

On still autumn mornings, when mist shrouds the Weald and the tops of the highest hills appear like dark and distant islands, it is easy to stand on this spot and imagine that you are gazing out across a vast mysterious ocean. On this summer's day, however, the neat farmland and wooded ridges were clearly visible, stretching peacefully away towards the South Downs, with barely a building in sight. Considering the small size of the county of Surrey, it has a surprisingly wide variety of scenery, with large areas of uncultivated heath, common and woodland. We were about to discover part of the explanation for this diversity.

To help us visualise the scene during the Mesozoic Era, Iain showed us copies of pictures painted by Karen Carr. Cretaceous Undersea and Coastal Environments are available on www.Karencarr.com/gallery.html. Wondrous animals ruled the world for millions of years but sadly, many became extinct. Fortunately, some left their fossilised remains to challenge and enchant a different species which evolved and rose to power much more recently, in ' the blink of an eye ' on a geological time scale.

Here we were, standing on a seemingly solid and immovable chalk escarpment, 170m above sea level, which was made mostly from countless billions of skeletons of microscopic planktonic algae which lived in a warm ocean roughly between 100 and 80 million years ago. It took them 50 years to build just 1mm of chalk and they succeeded in constructing a layer hundreds of metres thick.

To add to this astonishing phenomenon, the chalk no longer lies horizontal, as originally deposited, but here at an angle dipping northwards at approximately 35 degrees. Responsible for this realignment was the collision of the African and European plates which resulted in the closure of the Tethys Ocean and the Alpine Orogeny between 30 and 20 million years ago. The awesome pressure advanced across the European land mass and on into what is now the south of England, forcing the sediments up into an anticline about 150 km long and 50 km wide, with its long axis orientated east to west.

Since then the forces of erosion, accelerated by periglacial conditions during ice ages, have removed and recycled the top of this impressive structure, more correctly described, as Diana Clements pointed out, as an anticlinorium, as it contains many smaller folds. The remaining edges of this dome are now known confusingly as the North and South Downs. (I think they should be called Ups!) Between these rows of gentle hills, ancient sediments, which underpin the present countryside, have been revealed.

I took a very deep breath as we began our ' underwater ' journey back through the past 120 million years! Iain gave us all a sketch map of the area on which we were instructed to mark the geological features and boundaries as we followed the Trail. As can be imagined, these became the subject of considerable discussion.

The Trail started, somewhat ignominiously, about 100m behind the only public toilets on the route! At Stop 1 we puzzled over an unexpected exposure of rust coloured sandy clay soil containing pebbles and flints. These originated in the Upper Chalk but here they had been deposited on the top of it. It seems that this formation, very similar to the nearby Netley Heath deposit, was sediment from rivers which once flowed across this area from the south, which must have been higher about 1.5 million years ago.

Reappearing from the undergrowth behind the toilets ( ! ), we returned to the car park and walked slowly down the hill, searching for the end of the sandy clay and the beginning of the Upper Chalk. This was difficult as it was covered by short Downland wild flowers and grass. We all chose a position and drew the first line across our maps.

Stop 2 was the Viewpoint and information board where Iain did some arm waving, indicating clues in the vegetation which suggested different strata. Walking diagonally downhill, it was obvious that we were crossing the Upper Chalk which contained bands of tabular flint. The path was covered in broken and nodular flints, probably washed out by rain water as it dissolved the softer chalk.

Flint is fascinating and its formation is not completely understood. Possibly, at various intervals, climatic or other changes in conditions caused pauses in the deposition of the Upper Chalk. These promoted the development of flint using silica from the dissolved spicules of types of sponge which were prolific in the chalk sea. It is often found in fantastic, convoluted shapes (burrow infills) or even superficially resembling animals or parts of the human body! Some nodules contain fossilised remains of siliceous sponges or other sea creatures such as echinoids or brachiopods. It is extremely hard and has a characteristic conchoidal fracture. Its uses by humans to make tools, weapons and for building are well known.

Now longer grass, bushes and trees grew each side of the track and we were delighted to see some delicate and beautiful Common Spotted Orchids (Dactylorhiza fuchsii). A little further on, when we began to smell Stop 3 ( ! ), we noticed that there were no more flints in the chalk, so a second line was drawn across our maps to mark the top of the Middle Chalk.

Stop 3 was somewhat fragrant but, thankfully, fairly dry! Here we found Albury Downs Chalk Pit, now used to store farm sewage sludge before it is spread on the fields. By contrast, the exposed chalk was pure and white and it contained fragments of a bivalve called Inoceramus. The obvious cracks in the chalk face looked like bedding planes but they were faults and some had slickensides. Iain pointed out a thin band of marly calcareous clay dipping into the hillside at an angle of about 30 degrees. It has been suggested that particles in this darker band are volcanic in origin.

Escaping from the odour, we continued a short distance down the track until we noticed that the chalk had become darker in colour due to the presence of clay or mud. A third line was drawn to mark the top of the Lower Chalk, sometimes referred to as marl. Further on we found slabs of hard Upper Greensand in the bank on the right. It was slightly grey in colour, calcareous and contained glauconite. To the naked eye it looked neither sandy nor green, apart from the algae growing on the outer surfaces. Another line was drawn and we complained that we needed a larger map! Looking across fields on the left, Iain said that the line of the hedge marked the junction between the Upper Greensand and the Gault Clay. Exposures were hard to find because of the vegetation so we took his word for it and added yet another line to our collections!

Now the Trail gradually flattened out as we approached Stop 4. Ducking under bushes, left deliberately to conceal the entrance, we suddenly found ourselves in a place with an audible 'wow' factor. The abandoned Water Lane Sand Pit is quite small but it has high vertical sides shaded by ferns, trees and bushes, giving the place a rather spooky atmosphere. The clean, bright orange, marine, Folkestone Sand was laid down about 114 million years ago. The vivid colour was staining due to the oxidation or 'rusting' of the green, iron-rich mineral, glauconite. On the south side, bedding planes sloped down to the left, indicating underwater sand dunes and currents moving from right to left, towards the east.

Scattered on the ground were curiously shaped chunks of very hard, heavy, dark brown, iron-cemented sandstone, known locally as Carstone. These had fallen from contorted veins or lenses near the top of the exposure. Some pieces were lumpy or flat and rectangular while others were long and curved, resembling guttering. Carstone was highly valued in this area, not as a source of iron but as a durable building stone. Nobody seems to know quite how or why these rocks were formed.

Emerging from the gloom into bright sunlight, the path became wider and the valley opened out. The Bargate Stone was not exposed here and we passed quickly into the Hythe Sand which was more friable and fertile. On the left was the first house we had seen on the Trail and odd sized and shaped pieces of Carstone had been used instead of bricks in the walls. To add to the attractive appearance, little chips of Carstone had been pushed into the mortar at irregular intervals between the blocks. This was called galletting. Iain suggested that, in addition to being decorative, they acted as spacers to support the blocks while the slow-drying mortar, made with Folkestone Sand, solidified.

We crossed the road and walked along the pavement and over a culvert through which trickled the Tilling Bourne stream. Approaching the village of Albury, we paused to admire some pretty cottage gardens and more houses with galletted Carstone or Bargate Stone walls. We found a place where sandstone building blocks were deeply eroded but the little chips of Carstone remained poking out of the mortar in between. The Drummond Arms was a welcome sight and we sat in the garden and enjoyed a refreshing glass of beer and admired Iain's collection of fossils found in the chalk on previous occasions. Here were some he had prepared earlier!

After lunch we headed south again, walking up the steep-sided Blackheath Lane. Sunken tracks are characteristic of the Hythe Formation because it is soft and washes away in the rain. On the right we found an exposure of Hythe Sand which had a 'pepper and salt' texture. The darker grains were glauconite of marine origin and the lighter ones were quartz. Suddenly it occurred to us that the bedding planes were dipping slightly to the south, which meant that we had just crossed the fold axis of the local Peasmarsh anticline. Iain showed us how to mark this east-west axis on our maps.

After the excitement had died down, we continued up the hill to Stop 5 where we studied a good exposure of the Bargate Beds on the left of the track. The southward dip appeared steeper than it really was because of current bedding. Iain said that the dips wedge out to the south. Bargate Stone is mostly confined to Surrey and Sussex with a little in Hampshire. It is an oolitic sandstone cemented with recycled limestone and it is valued as a building stone, for example at Charterhouse School. Through a lens, minute ooliths or ooids could be seen. The theory was that these tiny spheres had been eroded out of Jurassic rocks. Fossils have also been found that originated in the Oxford Clay, a long way to the north, then transported by rivers and deposited here on the site of an ancient delta.

We turned left (east) near the top of the hill and took the sandy bridleway. Here there was a dramatic change in the scenery as now we were walking on infertile acidic Folkestone Sand which had been planted with conifers. On the path I found a very worn but unmistakable flint echinoid fossil (Conulus) which must have been transported over a long time and distance from the Upper Chalk where it lived and ploughed through the soft mud on the sea floor about 85 million years ago.

After about 500m we turned left (north) again and entered a narrow pathway going down the hill. We stopped to inspect a small exposure of the Bargate Member beneath the roots of a tree. Here it was non-calcareous, yellow, fine to coarse sand with current bedding dipping south at 13 degrees. The sides of the track became steeper so we recognised that we were once again entering the Hythe Formation. There was a surprising layer of chalk on the path which must have been brought here by people to reinforce the surface.

Stop 6 was next to a large exposure of fine brown Hythe Sand with current bedding dipping north at a low angle. We had crossed the hidden axis once again but in the opposite direction. Iain drew our attention to little round light-coloured spots which were infilled worm burrows. Some darker layers contained small grains of glauconite.

A short walk along the main road past Albury Estate houses with their extraordinarily ornate Pugin chimneys, and an old VR post box, brought us to a path up the hill on the left. This led to a forbidding metal gate through which we peered for a glimpse of the working Albury Sand Quarry in the Folkestone Formation (Stop 7). In spite of reassurances and plastic liners, I was not convinced of the safety of using this as a landfill site. We were disturbed by the amount of methane gas burning off and venting from an enormous upright metal tube.

Moving quickly on, we walked downhill (east) along the A25 road and crossed over to Stop 8 at the Sherbourne and Silent Pools, originally dug out hundreds of years ago to make reservoirs of fresh water. These were supplied by streams flowing from beneath the chalk. Sherbourne Pool lay mainly on Gault Clay with Upper Greensand at its northern end. The deep clear water in the Silent Pool above had a bluish tinge and there was an exposure of creamy coloured Lower Chalk beside the path at the stream end. It dipped north at 25 degrees. More lines joined all the others on our maps.

Climbing the steep hill beyond the pools on the way to the final Stop, we stopped briefly to look at a small exposure of white rubbly Middle Chalk with fragments of Inoceramids. A little further on we found the marker post 9 near a brick Second World War 'pill box' built on the base of an old lime kiln. In the past, every farm in this area had its own lime kiln to burn local chalk and convert it into lime. This was spread on the clay and sandy fields to fertilise and break up the soil. Just think of all those toasted fossils!

We gazed over the fence at the view back down the slope with a new awareness and understanding of the connections between the scenery and geology, and identified the rock sequence with the help of our maps.The path back to Newlands Corner passed over the flinty Upper Chalk once more and on to the crest of the scarp slope where we found more Netley-Heath type sand and clay with flints and gravel.

Thanks to the patient and expert guidance of Iain Fletcher, we had observed and absorbed an incredible amount of geology in one very enlightening and enjoyable day. On 30th June, 2002, Brazil's football team won The World Cup but we gained something of much greater and enduring value.

Joanne Cassidy.