Wednesday, 29 July 2009

Into the Devil's Hole


The Devil’s Hole (name changed) is a working quarry situated fairly close to the A1 heading north not too far from St.Neots. It is a shallow quarry in comparison with some others in the area because it is only the top 4 metres or so that are quarried.

These 4 metres of materials are sands and gravels laid down during the Pleistocene (Early Devensian) around 75,000 years ago and were subsequently scoured by glaciers during the last glacial period. Below these layers is a channel of Oxford clay dating back to the Jurassic, but this is not extracted here. Only the sand and gravel is extracted and this is why the quarry is shallow.

As you were no doubt aware, the Summer of 2007 had proven to be extraordinarily wet but in early July, after a week of rain, I arrived at the Devil’s Hole in bright breezy conditions with only occasional banks of cloud to break up the sunshine.

As the quarry is still being worked, you have to sign in and then be escorted to the area where we could start looking for fossils. The quarry itself, although shallow as mentioned, actually covers a vast area and we were taken to a couple of recently excavated areas that lie parallel to each other and these were to be our hunting grounds for the day.

Both mini-quarries were similar in layout and it was a toss of a coin to decide which one to start with. The stratigraphy of the glacial units was instantly clear as were the spoil piles of Oxford clay that were created as the excavators hit the ancient sea bed once the bulk of the sand and gravel had been extracted.

I started with the clay looking for ammonites and any possible reptile remains and after previous trips in the Oxford clay, I was expecting abundant fossils from the off. I was wrong. There was very little exposed, just the odd gryphaea and poorly preserved belemnite. I was a bit bemused by this but carried on looking convinced that there would be something, somewhere.

But still fossils were hard to come by, and after a while I decided to get up close and personal with selective spoil heaps. Since I’ve been fossil hunting, one of the best ways to start finding fossils when I’ve been struggling is to get close to the ground and start carefully sifting through dirt (or clay in this point). Today would prove to be no exception.

After a few hours of close up intense scrutinisation, I eventually found a few nice pieces including three tiny pyratised ammonites which are just a wonderful golden colour. I located one complete ammonite (species to be determined) that will need to be stabilised, a couple of beautifully preserved brachiopods, a tiny gastropod and some other ammonite pieces.

Whilst having a break and something to eat, word filtered through that some bone had been recovered from the quarry next door. “Typical” I thought, as visions of Ichthyosaur or Plesiosaur bones came to mind. For the second time I was wrong. The bones were from mammals of the Pleistocene, animals that roamed England not too long ago.

After lunch, further investigation revealed that a partial rib had been recovered, a partial ulna from possibly a bison, and amazingly enough, a mammoth task. Although, by mammoth standards, the tusk was small (about 3 feet) the tip was superbly preserved. As I was going to look in this quarry during the afternoon anyway, I hastened to get there somewhat more urgently!


This quarry was a little harder to traverse - there was water everywhere. The spoil heaps were similar though although they were very much in parallel lines, more so than the quarry next door. There was a few of us in the quarry now and I suspected that the best fossils had already been removed.

However, I was more than pleased when, after only half hour in the quarry, the chap who had found the tusk located an excellently preserved mammoth tooth only 50 yards from where I was. Today was certainly his day alright but at least it proved that were still good finds to be had.

As the afternoon wore on, nothing else was found and I resigned myself to the fact that I was probably going to end up boneless for the day. Eventually though I resorted to type and picked a likely spoil heap, got on my knees and started to look closely.

A piece of white “wood” caught my eye, roughly half-moon shape, buried in the spoil with only about 25mm exposed. Closer inspection revealed the tell-tale porous cell structure of bone and, holding my breath, I started to carefully remove the spoil around the base and the wonderful rich enamel colour of fossil bone appeared and confirmed that I had indeed found something special.
But what was it? I couldn’t determine what it was at first. It was big and held fast and I was particularly careful in removing the spoil. After 10 minutes or so I managed to remove an exquisite neck vertebra.

Unofficially it has been identified to belonging to either a bison or woolly rhinoceros – an amazing find. After carefully wrapping up the specimen, I continued to look in the immediate area for any further remains of the animal but the day was drawing to a close and, in the time remaining, I knew that further finds were unlikely.

Shortly afterward, we gathered together to compare notes and specimens. It had been a remarkable day with some nice fossils recovered. Our escort then led us from the quarries and back to the office to sign out. They had looked after us all day and a big vote of thanks is very much deserved. Thanks – you know who you are!

The rain had held off all day and I headed south for home. This was a first visit to the Devil’s Hole and I hope to return in the future, although this particular quarry is getting increasingly difficult to access, like so many these days, and opportunities are sure to be limited.

Footnote

And here it is. This is an exquisitely preserved cervical vertebra from a wooly rhinoceros. Compared to some preparatory operations that are currently in progress, this was a relatively simple process. What matrix that there was was easily removed, and after a fairly standard clean up operation, the entire bone has been stabilised with B72.




The problem with sub-fossil bone of course is that I'm not absolutely certain that this consolidant will do the correct job, but it will do for now. There are those that prefer PVA for this form of bone or maybe PEG 4000. I'm hoping to get the definitive answer at SVP in Bristol during September since this form of bone preservation will be getting some deserved attention.

Monday, 27 July 2009

PC Hell-o

Well, I have my computer back. There is no need to go into detail other than to say that when I mess things up, I can do it with some aplomb. The good news out of all of this is that I've met a real gentleman of the computer world who has spent no considerable amount of his own time putting things right. A big thank you Kris and a special mention of thanks go to my fellow preparator Mark who put me on to him in the first place.

As for the computer itself, well it would appear that the fix is one of those that is hard to quantify. It may last ten hours, ten weeks or ten years - there is just no way of knowing. But Kris has set the system up with a few fail-safe options and with the addition of an external hard drive I can rest easy knowing that all my data is at least safe.

So since reliability is obviously going to be a problem (and I hate that feeling of wondering if it is going to crash at any time), then I have no option but to invest in a new system in the near future. I suppose it was due anyway since I've had the current set-up since 2003 - ancient by today's standards. I'll time the purchase to coincide with the release of Windows 7, a quantum leap better than Vista by all accounts. Mind you, from a personal point of view, it will have to go some to beat XP - by far the most stable OS since Windows was launched many moons ago.

So next up is another field diary entry - computer permitting!

Tuesday, 21 July 2009

PC Hell

I'm posting from my work computer. Why? Well, since I have had my computer, I have managed all the hardware and software upgrades myself. Indeed, so completely pain free have the procedures been that any problems that arose have been methodically and systematically dealt with. Until now.....
A little while ago, the CD-ROM/writer stopped working, so I took the opportunity to purchase a new DVD-ROM/writer as an upgrade. At first everything went as well as could be expected. Yet again all would be fine. Well not this time.
To cut a long story short, my PC is now undergoing serious surgery by somebody who DOES know what they are doing. Suffice to say that the BIOS is corrupt, the OS needs re-installing etc etc. Why did I bother? I'm not sure that there is a moral to all this but one thing I know for sure - don't get cocky with your computer because when it does bite you the treatment is likely to be expensive! I'll be back soon (I hope).

Tuesday, 14 July 2009

Quarry Closure

I was saddened to hear this week that another brick works closed its doors for the last time in June, another victim of the recession. From a humanitarian point of view, it is again distressing that 61 people have lost their jobs and now find themselves competing for too few or non-existent jobs. Being in the manufacturing industry myself, I can totally relate to the situation and can say that we too are struggling to get through this tough period and I know I can speak for all my work colleagues in being apprehensive about the future. Certainly there are continuing hard times to come.

This particular works got its clay from the Cuckoo's Hole quarry, one of the most important Wealden sites in the south. This quarry shows beds in the lower part of the Weald Clay Group including beds B.G.S 3 and 3a (the Oakhurst Sand) and is from the Lower Cretaceous, Hauterivian, about 135 million years old. There has been some excellent material recovered over the years including insects, fish, crocodile and dinosaur remains.

I was only able to start prospecting there last year so this has come as real blow, not only from a personal point of view, but also in the bigger scheme of all things palaeo. The site itself is at the centre of many heated discussions just now as to what to use it for. Most controversial is the possibility of siting a waste incinerator there although this has come under the most fierce criticism.

But as for the quarry itself I have, as yet, no detail. It does have some protection since it is a designated SSSI (Site of Special Scientific Interest) which has it registered as "...an outstanding site with great potential for palaeontological and sedimentological research". As soon as I get some more detail as to the future of the quarry I'll let you know.

Incidentally, in the not too distant future, I'll publish my account of that first field trip at the Cuckoo's Hole and I'll also provide more in-depth palaeontological and geological data. I pray that it can be saved because, although only I've been there just the once, it's one of those places that feels right and it obviously has some impressive fossils to reveal.

Footnote

Cuckoo's Hole is a pseudonym. For most of the quarries that I work in, I never reveal its true name unless it is the public domain. This is to protect them since they are all vulnerable to illegal collecting which, regrettably, is becoming more and more prevalent. There have been many fossils, important to science, which have been removed this way and I will never knowingly give thieves (for this is what they are) any help in locating prime sites.

I will highlight any name changes as I go along. There are some of you who will know where I am referring to - most of you will not but I am adamant that I will do all I can to stop the unauthorised pillaging of these quarries, and I know that most of you will agree with these sentiments.

Wednesday, 8 July 2009

Return to Seatown


Seatown is situated on the Jurassic Coast in Dorset, not too far from the fossil hunting mecca of Lyme Regis. We first visited Seatown in May, 2005. I had always planned to visit this area before in the search for fossils but had been put off by the thought of hoards of tourists!

Eventually, though, the lure of complete ammonites and a sense of palaeontological history was enough to get me to Dorset. That first trip was a real eye opener. The weather had been atrocious that week and it rained heavily throughout the night before our trip on the Saturday.

I knew quite a bit about Seatown; I'd done my research. It was the best compromise location in the area since it was certain that fossils would be fairly abundant, maybe not complete ammonites but certainly plenty of bits. I've worked in various clay formations for some years now and know that quite often the best times to look in the clays are after heavy rainfall, but be prepared for very muddy boots!

By the end of the day, I felt we'd done quite well. A nice selection of both nautiloid and ammonite fossils graced our rucksack, including a few nigh-on complete ammonites. It helped that very few people were there and we had the beach virtually to ourselves. However, we didn't find any of the highly prized nodules that contain complete three-dimensional ammonites once prepped, and there were very few belemnites in evidence which I felt was strange (more on this later).

We left Seatown and then Dorset itself a couple of days later, but I knew then that I wanted to return and have another delve into Seatown's past. Early in 2007 we decided to return.

The Return



We returned to Dorset at the end of March 2007. This time the weather wasn't as "fossil-friendly" as previously but, on the other hand, it was just after the highest tide of the Spring and my hopes were high of at least enjoying similar fortune to that of our previous visit.

Low tide was mid-afternoon and we timed our arrival for lunchtime. It was a beautiful day, the sun was out and the cold northerly wind was blowing way over our heads. Again there were only a few people there as we made our way to the fossiliferous beds of the blue lias.

However, this time the situation was somewhat different. There was only one reasonable cliff fall which yielded a few nice pieces, but very little else. On our previous visit the clay cliffs were literally crumbling and falling before our eyes, but without the heavy rain they remained in fairly good shape.

On the other hand, the scouring tide had really cleaned up the exposed beds and in some sections we were walking on very flat stone, almost table-like. It was here that there was a marked difference from our last trip.

Exposed in extremely large numbers were belemnites and some were large for this particular locality. Previously they had been conspicuous by their absence and those that were found were tiny. This time we only collected one or two but the fact that they were present in numbers was surprising.

We continued our search but ammonites were in short supply, so we headed around the point at Seatown and proceeded to look for the elusive ammonite nodules. Despite our best efforts we struggled to find anything - a partial nodule with a partially exposed ammonite was all we could manage.



We turned back at low tide and headed towards the car, stopping to look as we went but without a lot to show for our efforts. Perhaps the most interesting fossils recovered were about half a dozen fully pyritized ammonites about 15mm across. I haven't quite made up my mind whether they are complete ammonites or whether they are the central coils of bigger specimens.

Either way, they are extraordinarily beautiful with an exceptional degree of preservation. It is easy to forget that they are 190 million years old (Lower Jurassic).

More people were scouring the beach by then and we returned to the car for a drink. At that point I knew that, whereas I would probably not visit Seatown again, at least for fossils, I definitely wanted to return to the Jurassic Coast and try again at another location, Charmouth for example.

Seatown is a great place to look for fossils, but please be aware of the tides. It is easy to get cut off if you are not careful. Also be aware that the cliffs are continually crumbling, especially in wet weather, so keep a good distance in these conditions.

Tuesday, 7 July 2009

Wyoming Geo Museum Closes

While I was away I was sorry to hear that, despite a considerable public outcry, the Wyoming Geological Museum has indeed closed its doors for the last time. Like so many people I find myself extremely disappointed by this conclusion, all to save 80,000 dollars as well, not a huge amount in the greater scheme of things.
You can read a little more here at ReBecca's blog. I guess I'm not that surprised but we must be ready for further battles to come. At least we are all a little wiser now and maybe go into the next scenario better prepared. Thanks to all of you who helped.

Monday, 6 July 2009

Back from the West....

It was very remiss of me not to mention that I would be on vacation for the last ten days but I'm back now. We've been to Cornwall, somewhere I haven't been to since I was little, and I do mean little!
We had a great time and the weather was near enough perfect, which is quite the statement since the rest of the country has been putting up with a rather oppressive heatwave. There was nothing during our holiday that was dinosaurian, paleontological or geological for that matter although I did do a little light reading to keep my engine ticking over.
Anyway, here is an image of the Cornish headland from Tintagel castle which is, according to legend, the birthplace of King Arthur. It does give you an idea of the sheer beauty of the area and the perfect weather that we had during our time there.
I'll put up another field diary entry soon. Until then, enjoy!