My first hunt at Liesberg, Switzerland, on October 24th

[pachy-pleuro-whatnot-odon]

Last sunday October 24th I decided to visit the old Andil clay quarry at Liesberg in Switzerland, just over two hours driving from where I live, to see what fossils I might find there. Now a nature reserve where collecting is tolerated as long as the natural parts are not disturbed, the deposits at this quarry, mined for cement production between 1934 and 1980, date to the Upper Callovian and Lower to Middle Oxfordian (source). It is thus stratigraphically - though not petrologically - comparable to the geology of Vaches Noires in Normandy, with which I'm much more familiar, albeit with the interesting variation that the bedding planes at this site have been uplifted and verticalised. The latter makes for an unusual experience working the mudstone layers in the middle of the quarry, and means that the oldest layers are to be found along the quarry's south wall (to the left if facing the quarry's back wall), whereas the youngest layers - most notably the Liesberg-layer, which geological limestone composition and embedded fauna of shells, sea urchins and crinoids is strikingly comparable to the Middle Oxfordian Coral Raq at Vaches Noires - are to be found on the north wall (to your right).

 

A situational satellite map from Google Maps

 

A commercial example of a beautiful Kosmoceras annulatum ammonite found in the quarry's Callovian layers

 

Seen from the parking spot at the quarry entrance near the top of the mountain

 

The buildings of the old quarry when you walk down from the parking spot to the quarry along a road with restricted access

 

 

Entrance to the quarry with an informational sign explaining the geological significance of the locality, as well as tells you not to get your hopes up, as most fossils you're likely to find will be steinkern-fossils

 

 

Spill heaps along the north wall, with the back wall in the distance, and a sign explaining the importance of the locality as a nature reserve

 

 

The path to the back wall of the quarry can be extremely muddy, and searching for fossils along the quarry's steep slopes is an activity undertaken at your own risk

 

 

 

Due to circumstances I arrived quite late in the day and only had a number of hours to search. However, I quickly concluded that the south wall (Callovian layers) and even the mudstone in the middle of the quarry (Lower Oxfordian) were not particularly fossiliferous, with a couple of hours of work only resulting in a corroded pyritised ammonite and a tiny fossil that may either be a crustacean or part of a sea urchin spine (if you know, please let me know). I did not find any fossils on the south wall, although the information sign at the entrance to the quarry had already forewarned that most of the fossils encountered would be steinkern fossils. I later picked up from a discussion between a solitary fossil hunter and another group of collectors, however, that this solitary hunter had found an ammonite towards the top of the Callovian slope two weeks earlier and had returned to collect it, only to find it gone. He hadn't found any new specimens, however. Interestingly, while the quarry was quite calm with only one or two other collectors for most of my time there, by the time I got ready to leave (around 17:30), the place all of a sudden became abuzz with groups of other fossil hunters.

 

 

Vertical bedding planes at the quarry and the two finds I made in the Renggeri clays: a heavily corroded pyritised ammonite and an unidentified fossil that may be either a bit of crinoid, or may be crustacean?

 

 

 

Following my lack of results (did I give up too early?) in the older layers of the quarry, one of my fellow fossil hunters suggested I check the quarry's northern slopes/spoil heaps, as there were plenty of smaller fossils to be found there. And, indeed, as soon as I stepped on these slopes I was able to pick up spine after sea urchin spine, stems and branches or crinoids, serpulids and even the occasional shell. The slopes were steep and it was hard to find a foothold, but at least I didn't have to return home empty handed.

 

Looking back through the quarry from the spill heaps along the north wall

 

 

Can you spot the fossils amongst the limestone blocks from (presumably) the Liesberg-layer?

 

Looking at the south wall from the spill heaps

 

Beautiful lighting when returning back to the car towards the end of the day

 

 

Here are some of my finds of that day.

 

 

Paracidaris florigemma echinoid/sea urchin spines; much more common and of better quality than I've found at Vaches Noires

 

 

Millecrinus horridus crinoid/sea lily stem (left) and arm (right) segments

 

 

Millecrinus horridus holdfast/root system (a special find for me) that I entered into Find of the Month contest

 

 

Serpulid worm tubes (left) and evidence for parasitism on crinoids (right)

 

 

Echinoids/sea urchins: a partial in matrix on the left and crushed and silicified specimens on the right

 

 

Shells, from left to right: fragment of trigoniidae indet. (?Myophorella sp.), Galliennithyris galliennei brachiopod and a piece of an unidentified clam

 

Section of horn coral

[bthemoose]

Nice report! I especially like the urchin spines.

[Tidgy's Dad]

Thanks for sharing, very interesting report and nice finds. 

[pachy-pleuro-whatnot-odon]

7 hours ago, bthemoose said:

Nice report! I especially like the urchin spines.

 

Thanks! Yeah, I like them a lot too. They're actually what made the trip somewhat worthwhile for me still in the end... 

[Manticocerasman]

nice report, to bad you didn't find anny ammonites.

Are there also Oolitic limestones in that location?

[pachy-pleuro-whatnot-odon]

33 minutes ago, Manticocerasman said:

nice report, to bad you didn't find anny ammonites.

Are there also Oolitic limestones in that location?

 

Thanks! Yeah, I'd also hoped to find at least some ammonites there, so I'm wondering whether there's a trick to finding them. If I figure it out before moving away from here, I might give the site another try...

 

As to your question about whether the limestone there is oolitic, I'm afraid I haven't quite developed the eye for that yet. If the oolites are obvious - as they are at Bouxwiller, for example - it's not a problem for me to identify them. But I've seen certain examples of oolitic limestone on the internet where I really wouldn't have guessed it being such. This is the case for the limestone at Liesberg as well (and most of the limestone I've encountered at Vaches Noires, to be honest - at least insofar as memory serves me), where the limestone seems generally smooth but with microfossil inclusions - but no obvious oolites. I've checked the few bits of matrix that I took along, such as the one adhering to my best urchin find, and I could spot only two possible oolites. So to the best of my knowledge, I'd say "no, the limestone is not oolitic".

[Ludwigia]

18 minutes ago, pachy-pleuro-whatnot-odon said:

I'd also hoped to find at least some ammonites there, so I'm wondering whether there's a trick to finding them.

 

I don't really think so. I believe it's more a matter of luck. I went there also once a few years ago and had a similar experience to yours. Had an enjoyable day there, but didn't really find all that much.

[pachy-pleuro-whatnot-odon]

3 minutes ago, Ludwigia said:

I don't really think so. I believe it's more a matter of luck. I went there also once a few years ago and had a similar experience to yours. Had an enjoyable day there, but didn't really find all that much.

 

As you say, could be just a matter of luck. But if you look at what @Kasia managed to pull out of the clay there (even if quite a number of years ago by now already), that's quite a different experience from the one I've just had

 

 

[RuMert]

Nice report and smart arrangement of pics:) Nice echinoids and spines, we don't have such good preservation here (maybe sometimes in Callovian I'm not very familiar with). Tests finds are exceptional and no such thick spines

[Ludwigia]

2 minutes ago, pachy-pleuro-whatnot-odon said:

 

As you say, could be just a matter of luck. But if you look at what @Kasia managed to pull out of the clay there (even if quite a number of years ago by now already), that's quite a different experience from the one I've just had

 

 

 

I guess she got lucky

[Manticocerasman]

32 minutes ago, pachy-pleuro-whatnot-odon said:

 

As to your question about whether the limestone there is oolitic, I'm afraid I haven't quite developed the eye for that yet. If the oolites are obvious - as they are at Bouxwiller, for example - it's not a problem for me to identify them. But I've seen certain examples of oolitic limestone on the internet where I really wouldn't have guessed it being such. This is the case for the limestone at Liesberg as well (and most of the limestone I've encountered at Vaches Noires, to be honest - at least insofar as memory serves me), where the limestone seems generally smooth but with microfossil inclusions - but no obvious oolites. I've checked the few bits of matrix that I took along, such as the one adhering to my best urchin find, and I could spot only two possible oolites. So to the best of my knowledge, I'd say "no, the limestone is not oolitic".

I  asked because of my experience in "The Vache noires" , there is oolitic limstone there and well preserved ammonites were often found in it. so if it was also present on your site it might have been a good idea to try to look in those layers for ammonites.

 

[pachy-pleuro-whatnot-odon]

18 minutes ago, Manticocerasman said:

I  asked because of my experience in "The Vache noires" , there is oolitic limstone there and well preserved ammonites were often found in it. so if it was also present on your site it might have been a good idea to try to look in those layers for ammonites.

 

While I'm aware that Vaches Noires has layers of oolitic limestone, I've mostly searched the clays and marls the two times I've been there now. As such, I don't have a lot of experience with the limestone layers at this site. But it's certainly a good tip to keep in mind next time I visit either Vaches Noires or Liesberg, even if the limestone at the latter site appears to be mostly calcitic. In any case, I'll keep on the lookout for it. Thank you!

 

By the way, it looks like it may generally be a good idea to take a sledge-hammer, next time I visit Liesberg, to crack open some of the limestone blocks on the northern slopes. Apparently they can contain rare crustacean remains:

 

 

[RJB]

For not finding much I have to say that is a great trip report.  I too like the urchin spines

 

RB

[pachy-pleuro-whatnot-odon]

In case any of you were wondering about the unidentified fossil mentioned in the report: turns out it's crustacean, probably part of a pincer...

 

Edited November 19, 2021 by pachy-pleuro-whatnot-odon

[Everhardus]

Nice report, shame you didn’t find any ammo’s. Better luck next time !!

[jpc]

Great report on a fun site.  The south wall, by the way, is the oolitic limestone layer.  I have found dozens of ammonites and some belemnites just looking through the rubble at the base of the wall.  Once when I was there a couple of German speakers were rapelling (=absailing in British) down the south wall to take the ammonite (big ones) directly out of the wall.  I think this is actually not allowed.   I was there 20 years ago before it became an amphibian sancgtuary slash nature reserve.  I think it is great what they have done there.

[pachy-pleuro-whatnot-odon]

6 hours ago, jpc said:

Great report on a fun site.  The south wall, by the way, is the oolitic limestone layer.  I have found dozens of ammonites and some belemnites just looking through the rubble at the base of the wall.  Once when I was there a couple of German speakers were rapelling (=absailing in British) down the south wall to take the ammonite (big ones) directly out of the wall.  I think this is actually not allowed.   I was there 20 years ago before it became an amphibian sancgtuary slash nature reserve.  I think it is great what they have done there.

 

Thanks, JP! Definitely something to take along next time I visit the site!

 

Actually, the rubble at the south wall is where I started my search. But as I didn't find any traces of fossils either in the rubble or the wall itself, I quickly decided to try my luck elsewhere. Later on other people tried the same strategy, with much the same result... But it's good to know that this should, at least in theory, be a viable approach.

 

I wonder, though, whether the site may not have become over-exploited in these past 20 years since you were there, as it's a small site (especially now most have be set aside for nature preservation) and there almost continuously were people there searching for fossils - even just regular tourists without any fossiling experience wanting to try their hand at it. And unlike coastal sites or active quarries, site erosion - and therefore renewal of fossils - at a place like this would be extremely slow, thus more prone to depletion?

 

I'm really trying to decide whether to give the site another go (which I probably should, as each site takes time to atune to). But it's rather far away, weekends until the end of the year are mostly booked, it's difficult to get away from the family in the weekend (young kids, poor wife ), and I can only use our current vignette into January, when I'm set to start a new job...! All this to say that if I try the site again, I'd be it to pay off... Last time was fun, and I got some nice fossils. But if I go again, I'd like to surpass my current finds - you can only have so much of the specimens I've currently brought back!

Edited November 20, 2021 by pachy-pleuro-whatnot-odon

[RuMert]

Sites usually need 2-3 trips to fully understand, then severe diminishing returns kick in. So I'd say, definitely visit it once more, but 1-2 other sites before that. Take wife&kids with you

[FranzBernhard]

3 hours ago, RuMert said:

Sites usually need 2-3 trips to fully understand

Nothing more correct than this! Maybe some pros may comment on this? Do they suffer from the same problem or get they everything at once? Well, they have a long list of observations to be made.

 

3 hours ago, RuMert said:

then severe diminishing returns kick in

It depends on the site, when it happens, but it happens...

Franz Bernhard

Edited November 20, 2021 by FranzBernhard