Wednesday, 16 February 2011

Return to the Bluff

The summer of 2010 was a lean time for field trips. Gaining access into new quarries continued to be nigh on impossible and although Quarry 4 was visited every now and then, there was still nothing of note to be found. There was no doubt that times were getting hard.

September arrived and it was time to return to the Bluff. Yet again I knew that it would be tough but equally I felt it was important to go and keep my eye in, so to speak. The weather was absolutely spot on for prospecting. There had been a little rain earlier in the week and the temperature was comfortable with an overcast sky, sunny intervals and the odd chance of a shower.

Again, having signed in, I made my way to the quarry to begin prospecting almost immediately. The quarry continues to look bleak and not very inviting since there had obviously been no new excavations for a long time now. At least the lake had receded well after a fairly warm Summer and it was easier to get around the quarry.

First look, as always, was the reptile beds and I made my way along the flanks of the outcrop, carefully prospecting as I went. Eventually I came to a spot that keeps popping out the odd bone fragment every now and then and soon found yet another piece of bone. This was a little bigger than the norm and had a nice shiny patina but it was too scrappy to be diagnostic.

Interestingly, this bone was also of a brown colouration whereas the other material from this spot is normally jet black. This one small area, about 5 metres square, is the only area over the last two years that bone continues to appear. With no sign that the quarry is to reopen any time soon I decided to return to this spot a little later and do some scraping of my own to increase the possibility of more bone showing up.

It was at this point that I was introduced to David Brockhurst, an extremely knowledgeable and likeable man who is key to gaining access to a couple of extremely interesting quarrys known as Shawdon (name changed). The northern quarry demonstrates exposures of the Wadhurst Clay and is extremely prolific. I do not exaggerate when I say that Shawdon is probably the most productive mainland site for UK dinosaurs in the country.

I’ve seen some fantastic examples and both preservation and variety of taxa is impressive. Ornithischians include Iguanodon, Polacanthus and Hylaeosaurus. Theropods are represented by Baryonyx, allosauroids and dromaeosaurs. Additionally there are pterosaurs, crocodiles, turtles and a wealth of other vertebrate material and it all adds up to somewhere that’s just a bit special.

Associated Iguanodon caudals from Shawdon. Photo by Peter Holloway.

Dromaeosaurid tooth from Shawdon. Photo by Peter Holloway

Shawdon, however, is very heavily protected and rightly so. Visits to the site are strictly regulated and are few and far between and although I have been attempting to gain entry for a while now, these things cannot be rushed. Still it was good to meet Dave and I felt we hit it off alright so we will see how it goes.

Incidentally, Dave obviously new what he was doing because he soon uncovered a nice vertebral centrum and, not long after that, an extremely rare pterosaur phalanx.

Soon after I crossed over the road and continued the search at the same level. This particular zone has sporadically yielded crocodilian material and I was lucky enough to find another croc tooth. Although a little worse for wear and having the tip missing, it was a chunky tooth and quite heavily striated.

A little further on I came to a newly exposed area of clay and shales. It seems that some material has been excavated to enable access to the pumps and lines that keep the lake at a manageable depth. Despite the brickworks being mothballed, it was good to see that the staff were keeping the flood water under control – presumably so that the quarry could be worked immediately if required.

I looked through the newly scraped area but found nothing. This wasn’t too much of a surprise since it was in the lower beds and vertebrate material is seldom found here. After a while I decided to cross the quarry floor and head to the fish beds. There have been fish scales, verts and other bones found here over the years.

However, this area hasn’t been worked for many years and finds have declined recently – so much so that I found nothing at all earlier in the year. Unfortunately, this was the case again – not even a solitary scale could be found. It was at this point I thought it was time to take some proactive action and utilize a methodology that I had learnt from Quarry 4.

At Quarry 4 there is a small section of clay situated just above the Kellaways that yields many fine lepidotid scales. Once those that are exposed are collected, the exposure is lightly raked up and the surface broken to enable the rain to soak in and break up the matrix. This works a treat and on the next trip there are always more scales that have weathered out and are ready for collecting.

The grey fish shales - in the centre of this image.

So I spent some time breaking up the surface of the fish beds, especially those areas that have produced in the past. Quite a large area was prepared and it will be interesting to return in the spring to see if this produces or not. It certainly won’t hurt, that’s for sure.

Leaving the fish beds, I crossed over to the northern exposures and prospected there. As I approached another bone producing site, the weather deteriorated and started to rain but this wasn’t too bad and gave the clay and shales a dampening down which I find always helps to highlight fossils. But the north bank didn’t produce either. Finding material at the bluff continues to get harder and harder.

Eventually I moved back to the bone producing reptile beds in the south east of the quarry and decided to put to use the same Quarry 4 technique here as well and raked up the bone producing exposure, hoping to encourage more weathering for the following year. I was pleased with the effort put in and covered a decent area and am hopeful that this tactic may pay off.

I continued to prospect for a while afterward, carefully going over older ground before moving to the top of the quarry and checking out the old spoil heaps. Intriguingly, there had been some fresh movement of spoil for reasons unknown, and this gave me the opportunity to look at some new exposures but, alas, nothing turned up and I decided to call it a day.

It will be interesting to see if the prepared areas turn up any new material. Hopefully another winter may reveal some new bits and pieces and I hope that the crust of compacted clay may actually be broken up this time – I sure as hell hope it doesn’t get any worse!


Post a Comment