Recently I was able to get up to one of our sites in Ontario with collectors Kevin and Matt after some aborted attempts due to weather. Malcolm is due to join us next week for a 2-day trip.
There is an incredible amount of work to do to get this site up to productive par. Winter saw the collapse of the upper erosion-resistant shelf, and as it tumbled it took a lot of overburden down with it, burying all of last year's benches.
This is what the site looked like in January when I paid a short visit during a temporary thaw. To give a sense of scale (since I failed to do that in my haste taking this shot), those blocks are about 3-4 feet high. Up behind were the benches we had been steadily making last season, now buried.
Last season was very good at our site once some of us were able to get down to one of the productive trilobite layers, and it was fairly common that a day's digging would mean going home with 2 or more full specimens. It was the result of many hands working those benches, expanding them, and getting at a layer that pulses here and there, pinching in and out.
We arrived in the morning with our arsenal of tools, prepared to do a lot of site preparation work - shovels, picks, the entire spectrum of hammers.
A picture of Kevin.
At this point, Kevin and Matt had been able to open the bench back up a bit more after Malcolm had done some work the previous week. The problem is that we have lost our layer, and it is still uncertain if what is below our feet here is already exhausted (likely is), and so there is little choice but to bite deep into the cliff and work our way down. This is not as easy as it sounds: for every foot deep we need to expose, there are about 6 or more feet of overburden and shale blocks to remove - and this increases the deeper you need to bite into the slope.
The other challenge is that a lot of these blocks are interlocking at various angles, and they need to be "unlocked" by removing key pieces as you follow a fault, some of which go on for a long time. It is not uncommon to think the fault will end only to find it wander in far and intersect with another fault that needs to be worked first, and maybe another one that jumps ahead in the sequence. What may look like a simple unlock of a slab and removal becomes complicated and even more labour intensive in a hurry.
Matt and Kevin up at our bench.
We put in a solid six hours of work to expand this, and we are not anywhere close to exposing enough to get this site productive again. As you can see above, there are three "hollows" that each of us worked. I worked the middle one where Kevin is sitting, spending all day on just one stubborn slab that was interlocked in four places and would simply not let go as there was no point at which it could be dug in and levered out.
Some weathering will need to take place. We constantly bumped up against layers that where the matrix was dense and would simply shatter into shards rather than come out large and clean, leaving a messed up jagged face. If our tools cannot find a place to bite deep and gain purchase, the shale just chips off diagonally across the splitting plane. That set up for an agonizing game of inches, always in the hopes that we could find that right piece to unlock the shale puzzle.
Fossils from these upper layers were of poorer quality, mostly. Very turbid, agitated deposition environments that gave up a lot of bits, or were otherwise just stuffed with brachiopods (which become a bit of a nuisance quickly). A few very thin nautiloids were spotted, but none of those nicely plump pyritized and ribbed ones. There were zero ammonoids apart from some traces of living chambers, which told me we were not quite yet at the layer we needed to be as those are heralds of coming close to the trilobite layer. Pyritized worm burrows, brachs, and trilo-bits dominated the rocks. We're still too high up in the strata, so we are still trying to dig in, and then down.
We'll know when we hit that trilobite layer as they tend to congregate together. The general rule is if you find one complete, take it home and probe the matrix for more.
As for the site itself, it is still going to take a few more long days to get it ready for the season. The tricky part is in planning the day so that we don't do all the excavation work in exposing the layer, have to leave at the end of the day, and someone else simply exhausting it without having done the grunt work required. But this site is nowhere near the point where that is in danger of happening. We also reason that we are coming close to this particular exposure having one last good season in it before it becomes untenable to work it anymore as we are losing the slope, and would probably have to work down 20+ feet of rock from the top to create new benches.
Each of us came away with 3 or so potential full ones, mostly damaged. These are the isolated full ones you can expect to encounter in the bits and pieces layers, and their preservation is generally quite poor (and they are flaky and delicate to begin with). Here is one of mine missing the the left part of the cephalon and the anterior portion of the glabella. A prep practice piece, or fodder for reconstruction parts.
In all, the trip was all about site preparation, not so much fossil finding. That will come, but only after we put in quite a few more days of heavy digging, hammering, and hauling. It was fantastic to work alongside Kevin and Matt, as they are a great and hilarious bunch of guys. When we trudged back to the cars at the end of the day, Kevin set me up with an Isotelus "mafritzae" that he expertly prepared. Kevin prepares and sells trilobites almost exclusively to high end clients, and this trilobite here - as top shelf as it is - is hardly representative of the gorgeous pieces he finds and prepares.