Tuesday, 10 June 2014

From the Toarcian to the Callovian Pt.2

The following day we decided to approach the bay from the south which was essentially the other side of the rock fall. Simon had already climbed up and around the fall to check out the other side to see if it looked fossiliferous. Simon was surprisingly quick and agile as he skipped over some extremely rough and acute terrain and never looked in danger of having an accident.
We had waited on the north side of the fall while he scouted and, after about ten minutes, he quickly reappeared and reported that the exposures looked similar to what we were looking through and suggested that there were almost certainly fossils to be found. This was good enough for us and seemed the sensible thing to do in light of their limited time in the north east.
And so, the next day, we dropped down a steep hill to the cove, about a mile south of our original bay, and prepared to head north. We believed that it would probably be a 30 to 45 minute walk along the coast to reach the desired spot although we would naturally look for fossils as we went since this whole coastline was remarkably rich in remains and decent specimens could crop out anywhere.
We had only just rounded the corner of the first promontory when we came across an exposed wave cut platform and straight away we could see several compressed ammonites and a couple of belemnites. Just beyond this was a very apparent and recent cliff fall displaying a patch of pebbles, rocks and large sandstone blocks not unlike the rock fall we had encountered the previous day. Immediately we found some bits of ammonite amongst the pebbles but as we approached the fall we could see, unsurprisingly, that other collectors had already been here and the remnants of split nodules  was indicative that the best specimens were already long gone. Or were they?
Amazingly, amongst all the debris, Simon managed to extract a large nodule that appears to have two very intact ammonites along the same bedding plane that should, if luck is with us, prepare really well and will be a superb display piece in due course. This will be almost certainly be prepared in the laboratory back at the NHM and so will have the best care and attention – fingers crossed that the ammonites are indeed as well preserved as they appear to be.
However, this was a rare find and we were soon heading off north for our intended destination. We scoured the headland as we walked but fresh exposures were not obvious and there was a growing increase in the amount of large sandstone blocks and debris we had to clamber over. We arrived at the next promontory only to be greeted by a sea of boulders and crevices that made walking tough and unforgiving. To add to our woes, the wave cut platform that was now exposed by the receding tide was extensively covered by seaweed and even getting to it was problematic.
Undaunted we pushed on over this never ending jumble of rock, mudstone and weed and, to be honest, it was physically extremely tough as well as being hard mentally since you were constantly concentrating on each and every footstep. A misplaced footfall might possibly mean a sprained ankle or even a broken leg and the weed and slime that covered the rocks and mudstones made the situation somewhat treacherous.
We decided to get to the next headland and hopefully we would be at the exposures we were aiming for. Imagine our despair as we rounded the headland to be greeted by another extensive field of rocks and boulders as bad as the field we had just negotiated, with the next headland appearing to be some distance off. Although we agreed that it was indeed likely to be our target spot we decided to call it quits and head back. This decision was not taken lightly but we had to take into account the amount of time it would take to get there, time to look for fossils and then the tide would have turned and we could not afford to misjudge our return south – especially with the terrain being so hard to negotiate.
We headed back south and began the long trudge back to the cove with our heads down to ensure we made it in one piece. Eventually we got back to where Simon had found his superb ammonite nodule and spent a little bit of time searching for more fossils but to no avail. We returned to the car and quickly back to base since Simon and Mark had to leave for London almost immediately. Saying our farewells, I immediately made preparations for the following day.
The weather deteriorated during the evening and another heavy sea mist closed in. I went for a walk along the top of the Lias cliffs and peered through the gloom but you could hardly make anything out. Only the sound of the waves broke the silence and for a moment I felt as if I was living back in the Jurassic. The great sea dragons abounded in the sea below me and pterosaurs flew all around me in the dense sea mist – the world must have been a truly awesome spectacle back in the Mesozoic.
The following day I descended down the cliffs, headed south and returned to the spot where the three of us had done well a couple of days previously. The sea mist was still pervading the atmosphere and you could not see probably a hundred metres either way but this just increased the sense of anticipation and, best of all, I had the entire cove to myself.
This time I decided to concentrate on this one area and spend a considerable amount of time on my hands and knees looking at every nook and cranny I could find. I would also check out some of the gullies and dips in the mudstone platform itself since they acted as collection points and there were many different rocks and stones that were trapped in all kinds of cavities.
Immediately this process began to pay dividends and I found a couple of nice ammonite nodules fairly quickly. When I extended the search onto the platform and began perusing the crevices for fossils I very quickly had one of those “wow” moments. As I peered around a boulder and looked down, there in a gully, just about sitting proud of the water was a wonderful pyritised ammonite glistening in the half light. It was almost as if somebody had placed it there waiting for me to find it and I took a couple of photographs of it in situ before gathering my prize.
Only fossil hunters understand the sheer buzz you get when you find such a fossil. That is not to decry the achievement of finding the vast majority of fossils but rather to celebrate that electric joy you get when you find a stunningly complete specimen, the glossy sheen of an immaculate tooth or, indeed, a gorgeous pyritised ammonite – there is no other feeling quite like it.
The platform gullies and crevices ended up being rather productive and, because they do not receive the attention that the foreshore generally receives, the fossils were often well preserved. Eventually the platform became decidedly weed covered and finding fossils problematic so I returned to the foreshore to continue looking amongst the gravels, rocks and boulders.
Throughout the rest of the session I recovered fossils including a couple of nodules that should contain complete ammonites. I know I often say this but getting onto your hands and knees and getting into spots that can seldom be seen from the standing or stooping position continues to pay dividends. One such very obvious boulder contained an ammonite nodule that must have been missed on countless occasions only because it was slightly exposed at the base and I only spotted it because I had my head stuck to the sand. Fortunately I managed to extract it safely and is another waiting for preparation.
Another fossil which I spotted in this fashion was a superb bivalve – the only example I found during the whole week. This too was secreted in a crevice and took some nifty chisel work to persuade its release from its ancient tomb. I really like this fossil and was thankful that I managed to find it. However, the elusive vertebrate fossils remained just that – elusive.
This is almost certainly due, in part, that you become focussed on finding ammonites and looking for nodules so you almost certainly miss other fossils. This is often the case in formations such as the Oxford Clay in which the sheer mass of ammonites and belemnites often preoccupies your line of vision and makes it difficult to differentiate other fossils – “noise” I call it.
However, I have no doubt that I was not missing much vertebrate material, if any, since I am very familiar with these kinds of fossils although I am nowhere near as familiar with these exposures as someone able to visit them on a regular basis. Regular prospecting at any site makes a tremendous difference to your find to visit ratio as you learn more and more about the exposures and the fossils they contain.
Gradually the mist dissipated and the sun began to shine and the day became a little warmer. I covered a very significant section of foreshore and amassed some very nice fossils indeed and I admit to being a little surprised that I was still able to glean a couple of nice ammonites quite higher up in the succession than expected.
Satiated for the day I made the long trek and climb out of the cove and did I know that I had had a good day as the weight of fossils on my back began to tell – the back pack seemed to gain more weight with every step up the steep trail. Eventually I made it back to base and took a look at my haul before washing them off and they made for a visually stunning display as they glistened with water. Soon it would be time for the next trip and I needed to decide on the location and eagerly began planning ahead.


Post a Comment