Wednesday, 15 December 2010

Quarry 4 Produces


July arrived and I was due to head south again but the news that the Cuckoo’s Hole quarry was closed knocked the stuffing out of me a little bit and I was very disappointed not to able to visit. I could have visited the Bluff as well but, for me, it wasn’t time yet.

So, at short notice, I called Mark to see if he was up for a trip to Quarry 4 on the same day that I would have headed south. Luckily for me, he was and we met up on the Sunday morning at 9AM ready for the hunt. Yet again you could see that another big section of clay had been removed and we walked briskly, eager to start prospecting.

As we approached the back of the quarry, the shell/reptile beds were fully exposed and there were great masses of concretions that were showing on the surface. About thirty yards from the back of the quarry, a long spoil heap had been drawn up by the excavators and this, unusually, was not contaminated by old bricks and there was plenty of new clay to look over. I would save this section for later.

We both began with the ancient sea floor, carefully walking, looking at the nodules and every exposed sections of clay in between. There were two or three really big belemnites that had, unfortunately, been crushed by the excavators and a few Gryphaea of unusually large size fully exposed on the surface but these were ignored. Bigger prey was the order of the day.

After a while, Mark brought to my attention a nodule that had obviously had something entombed within. Careful scraping with picks and brushes revealed the remains of a fish in the block. We could clearly make some spines, presumably part of the dorsal fin, an operculum, a tooth and lots of other bits and pieces. Neither of us are heavily into fish and the exposed remains were obviously too fragmentary to even guess at identification.

Image courtesy of Mark Graham © 2010
But the block was certainly a prime candidate for preparation and it was obvious that the block contained a lot more unexposed bone and looked certain to be a good specimen. We decided to take the block out and first of all consolidated the exposed bone and then proceeded to remove the clay from around the block and leave the concretion sitting proud of the surface. We then attempted to split the block at an appropriate spot. Easier said than done.

For future reference, let me tell you that concretions are very aptly named and, despite the use of extreme force with a variety of chisels and hammers, could hardly make inroads into it. Time was obviously an issue and it became apparent that we were hardly well equipped for this sort of excavation. I think we both understood a little more now and the reasons why concretions with bones in are often taken out whole. There appears to be no other option.

Mark decided to call Cliff Nicklin and see if the museum would be interested in the fish. Cliff agreed to arrange an inspection of the block and then the matter would be taken from there. Satisfied that we had done all that we could, we decided to move on and continued to prospect.

We carefully moved on and arrived at the previously cleared bed. Again, despite our keenest attentions we were coming up short. We took a break for lunch and then headed back to area where the fish was. Mark continued to scour the area and I, reverting to type, started at the beginning of the spoil heap and slowly moved along, often sitting in the middle of the heap and looking very closely.

As I looked into the clay I saw what I thought was a dead slug and immediately thought it was strange to find a slug hundreds of yards away from any vegetation and in the middle of a barren clay quarry. I went to poke it to see if it was dead and was surprised that it was rock solid! As I lifted it up I could see that it was distinctly marked and as I cleaned it off realised that I had a crushing tooth from a hybodont shark.

It was big at over 50mm in length and I later identified it as Asteracanthus ornatissimus. This was a really rare tooth and big – I was absolutely delighted. The preservation and markings on the tooth were beautiful. After showing Mark my prize I carried on surveying this very same spoil for more fossils. I wasn’t to be disappointed.


Astonishing detail in this close-up

Cliff has always said to me that, because everything in sight is clay grey, you have to look for shapes and I have been trying to tune in for some time now. I also knew that a lot of my better finds over the years have been when I get on my hands and knees and look at the sediment really closely. This combination of shapes and close up work was about to pay dividends.

I worked my way along the spoil heap slowly but surely. After about 20 yards I virtually laid my head on the side of the spoil and looked along its length. About 5 yards away I made out a distinct concave shape in the spoil that was obviously out of place, and, as I approached it, I knew what I was seeing. Sure enough, standing proud in the middle of the spoil, was a huge vertebra. It even had a large proportion of the processes intact, despite being rolled about goodness knows how many times by the excavators.


Spot the vert!

I was absolutely delighted. After all the blank trips, all the miles I’d driven and the steep learning curve at Quarry 4, here was my reward. The vertebra was massive and obviously from a very large pliosaur. Not only were the processes preserved but a section of rib had become detached and stuck to the centrum during fossilisation. Again I called Mark to show him my prize and then I wrapped my prize carefully and carefully placed it into the rucksack. We both scoured the immediate surroundings to see if there were any more remains to be found but nothing turned up.

As the day approached its end, it was good that we were, at last, coming to terms with the quarry. We carried on prospecting in the general area of the spoil heap but to no avail. Nothing else was found but that was to be expected and, in the circumstances, I didn’t want to appear greedy!

As we left the quarry, I was to return a couple of times later in 2009 but nothing of note was recovered. We also received word at this time that Quarry 4 was finally going to be closed during 2010 and was to be flooded and turned into a nature sanctuary. This was sad but it did mean that Quarry 5 was finally going to be opened and, as Winter approached, machinery was slowly being transferred to the new site.

Preliminary excavations begun and many tons of glacial sands and gravels were removed but the drag lines soon reached the clays and excavation began in earnest. At this point there was still one drag line working Quarry 4, although we didn’t know why. The reason why became clear to us during the next few months.

2010 was approaching fast and there were changes ahead but we all looked forward to the New Year but first we had the ravages of one of the worst winters in years to contend with.

1 comments:

Anonymous said...

lovely dorsal that. Interesting to see that it's uncrushed. Can you give us the dimensions and weight please? Is one of the paired foramina visible on the other side?

best wishes

Paul

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