First Week of the Season

[Kane]

I was able to get out three times to three different local spots. Fairly underwhelming results, but it was nice to get back out in the field now that the snows have melted. The first two spots I had effectively tapped out last year, but it always pays to check in. The third one, featured here, was a new prospect. I had made a cursory visit last autumn, and then tried to jump the gun by going here at the end of February but the snows were still too deep. 

 

Exploring the Dundee Formation is admittedly a pretty niche focus. There is probably a good reason why it isn't the top destination for fossil collectors on account of lack of available outcrops, some very poor facies, and occasionally being brutally hard rock -- so much so that it is commonly used as armour stone for landscaping. 

 

Friday's prospect had quite literally hundreds of tons of locally quarried rock. Sadly, about 99% of it was not very gainful for trilobites, and was from a lower facies that is characterized by being a high energy packstone filled with crinoidal bits, broken brachiopods, and shreds of fenestrate byrozoans. 

 

[Kane]

That being said, the rocks are highly fossiliferous -- it is just that they aren't always the fossils that I'm looking for! Seen here are some typical Dundee rocks with crinoidal sections and abundant brachiopods. Some of the layers are nothing but brachiopods, but they might become monotonous even for the most die-hard brachiophile. 

[Kane]

Eventually I encountered the right source rock where trilobites are more frequent. The tell-tale sign of seeing a larger spirifer suggests some larger fauna will be present when splitting. I would not be surprised to bump into pygidia of Pseudodechenella sp. as they happen to occur in every horizon of the Dundee to greater or lesser extent, but almost always as fragments. 

 

The facies presented here is identical to that I collect in a nearby town. It is a sandy tidal matrix with abundant brachiopods and rostroconchs reaching impressive sizes, but also the occasional trilobite fragments.

[Kane]

And I mean very abundant. Some layers are almost entirely supported by brachs or rostroconchs. Sadly, only a small pocket of this pile contained this facies, so I tapped it out fairly quickly.

[Kane]

As I was preparing a trilobite faunal list for this location, the occasional trilo-bit was recorded in the field notebook. Here we see encircled in red bits of Coronura aspectans. The only thing I took home, however, was this single example of Odontocephalus sp. pygidium. 

[Kane]

Among rocks of a different facies, there can be Pseudodechenella fragments in a reefal mix. The camera doesn't quite capture the colour very well, but almost all the fossils in this type of rock are purple. The numerous entangled corals is reminiscent of Hungry Hollow strata, but not as diverse and interesting.

[RJB]

Always nice to get out into mother nature even if one does not bring much home. 

 

RB

[Ludwigia]

Nice to see that you're getting back to it again. At least you found a few trilobits.

[Kane]

Lastly, a disappointing example of a thoroughly weathered pygidium of Coronura aspectans, mostly showing in the negative while the positive is not as diagnostic. I wasn't going to take this one home. 

 

There is a healthy array of trilobites in the Dundee Formation, but in most cases they will only appear as fragments in what is regularly very tough limestone and dolostone. Birchard has identified six main facies, but that does not account for localized variety on account of various depths and depositional environments. I would definitely recommend the Dundee for the brach and coral lover as it rarely disappoints on that score. For trilobites? Well, it's a tough slog for slim pickings!

 

So, no great shakes on three days in the field, but it is early in the season.  A great excuse to get outside and warm up the tools. 

[Malcolmt]

One of these days they (she who must be obeyed) will let me out of the house

[Tidgy's Dad]

1 hour ago, Kane said:

 they might become monotonous even for the most die-hard brachiophile. 

 

Hmmmm. Wanna bet? 

 

Nice report, it's great you've been able to get out again, the finds will flow soon enough. 

[Tidgy's Dad]

1 hour ago, Malcolmt said:

One of these days they (she who must be obeyed) will let me out of the house

Maybe mine will let me back in. 

[Kane]

1 minute ago, Malcolmt said:

One of these days they (she who must be obeyed) will let me out of the house

I think they call that "obtaining hermission"  

Well, the one advantage is that I can confirm what spots are not worth the effort, which spares you a wasted day. Had this site been productive for the kinds of fossils we collect, you know I would have called you over to help reduce my fossil burden!  

[Kane]

2 minutes ago, Tidgy's Dad said:

Hmmmm. Wanna bet? 

 

Nice report, it's great you've been able to get out again, the finds will flow soon enough. 

One thing I forgot to photograph is this one horizon of tiny red and white brachs. The layer runs about 30-90 cm deep and it is nothing but this one brachiopod! They tend to be small and relatively smooth/featureless. I've been wrongly calling them Devonochonetes, but if I can remember to snap a picture next time I encounter them, I'm sure you'd nail it immediately!

[Nimravis]

Great trip report and I’m glad that you got out collecting.