Visit to "Riprap Hill"

[Kane]

Just going through the photo archive, and have a few more from the same area that I don't think I've posted here yet. A very pinkish brach coquina:

[Kane]

Serious oxidation:

[Kane]

This one includes a partial Eldredgeops cephalon I may have posted last year, if only because of its unusual size.

[Kane]

An update on this honey hole o' mine.

 

I've gone back to it several times since the collecting season started. Trying to identify which formations have been dumped there has been a challenge as everything is mixed together... And, every time I think I have a fix on where the rocks came from, I find some other species that causes me to revise my assumptions. No significant dumps have occurred in a few years, and now I suspect there have been numerous dumping events to form the hills.

 

When I first started poking around here in 2013, I was finding stuff that was typically Hamilton Gp and Dundee Fm. In the past year, I've found stuff that only occurs in the Bois Blanc, and the Amherstberg Fms. So, apart from finding Eldredgeops rana trilobites, I was plucking out as of this year a lot of Anchiopsis anchiops, and one pygidium of a Mannopyge halli. 

 

So far, so good. A fairly wide spread of Devonian age rocks. I can work with that. Until today.

 

This picture is just a few scattered brachs and one gastro I picked up. Fairly typical stuff for this site:

So, while picking over what I've picked over hundreds of times already, breaking what I've broken into tinier bits, I come across two pieces of black shale. And this piece came up. My eye was attracted to it because it looked like a trilobite fragment. However, the pleura was familiar to me - just not from this site:

[Kane]

I was in disbelief. What would an Ordovician trilobite be doing here? The nearest Ordovician sites are a good 200 km away. I would not think they would truck in fill from that distance. 

 

Well, I picked it up anyway as it really did look like a fragment of Pseudogygites. I flipped it over an saw a very tiny bit, barely bigger than a pinhead. I put it under the microscope and - behold - the cranidium of a Triarthrus. And so I can now confirm ever more possibilities at this site. And so I can also be ever more frustrated, confused, and surprised by my time there.  

[Plax]

is this glacial till? This would seem more likely than rocks trucked 200km. Sorry if this question has been addressed previously. The piece with the attached oyster that looks like exogyra still has me curious.

[Kane]

Hi @Plax - That is an entirely reasonable question. That being said, the materials have been deliberately trucked in to build the ski runs. I've watched some of the unused material in large mounds over the years go from bare, to weedy, to saplings taking root. The distance the material (seems to have) traveled doesn't seem terribly cost-effective, however!

 

Around here, it seems like glacial till all the way down! The area was inundated by a wide river (now just a modest snaking slash) after the last glaciation event 13,000 years, but it lay down up to 10 or so metres of till, dirt and sand. There are virtually no exposures in the city.

 

That one Jurassic coral piece was found in the adjoining woods near a residential area, so I suspect it was a garden piece tossed away.

[Kane]

Just another trip to my spot. Nothing fantastic, but a few trilo-bits. 

 

First up, a big coral because who can get enough of coral?  

Next up, the pygidium of a trilobite which *might* be Anchiopsis, but the fact that it is a bit worn makes it too tough to make out if there are those classic incised axial rings.  So I'll just say... "maybe?" About 8 mm across.

[Kane]

Another trilo-butt. It is quite pustular, and is mostly buried. I've tried to remove some of the matrix, but this stuff is a lot tougher than my Dremel can handle. What species? Not sure. It could be Eldredgeops for all I know - such is the nature of this mixed bag o' rocks that has stuff spanning a lot of different formations in a big jumble. 

And lastly, what *appears* to be a genal spine in the same rock. Much of the shell of it got stuck on the impression side.

[Wrangellian]

I like that big chunk of coral!

What is the size of that 'genal spine'? Seems quite 3D and thick-shelled for a trilo spine...

[Kane]

3 hours ago, Wrangellian said:

I like that big chunk of coral!

What is the size of that 'genal spine'? Seems quite 3D and thick-shelled for a trilo spine...

I had been meaning to take a picture of that coral hunk on several trips there. I keep leaving it there as there isn't much room for it in the house, and the garden has already got its own fossil reef going.  

 

The "spine" is just shy of 2 inches. The calcareous rind is pretty thick, which in itself probably rules out trilo. There are no evident striations running length- or cross-wise, but instead a kind of subdued lumpy texture which makes me think it might be a fragment of a brach. Apart from that, the matrix itself has slightly larger grain, suggesting sandstone, and has a few cornulites in it. The pygidium pictured above the "spine" object comes from the same type of rock - sandy-grained and tough, with no clear bedding planes as it breaks in chunks. Not the easiest medium I've worked with, but certainly not the toughest! 

[Wrangellian]

Too bad you can't find a place for that coral.. I'd take it if it wouldn't cost an arm and a leg to ship it over here.

Maybe you should post that hornlike thing in the ID section?

[Kane]

The season here draws to a close. I managed to get in what will perhaps be one last poke around the rocks at my hill/pit/woods. I managed around 35 visits this year, most times coming home empty-handed, and other times adding new trilobite species to my collection. In the course of the season, a little less is exposed due to the continual advancement of undergrowth. At the moment, the dry burdocks are dominant (as I pick them off my clothes!).

 

From a recent trip in late October, just a pair of colourful and plump Leptaena bookending another brach.

 

More Leptaena:

 

 

Giving these trilo-bits a home. Just cuz.

 

 

 

And, playing hooky from work today - or, taking a "sanity break," one very last trip to admire the colours.

 

One apparently large gastropod steinkern

 

A heavily oxidized brach in autumnal splendour:

 

 

The path that beckons you to walk it. This alone, to me, justifies putting work aside. Autumn is certainly the glorious, vibrant crowning of a year:

 

[FossilDAWG]

Nice fall color (or colour if you prefer)!  Down here we have a few trees that turn yellow or red, but this year it seems we are getting a lot of brown. 

 

Don

[Kane]

Just now, FossilDAWG said:

Nice fall color (or colour if you prefer)!  Down here we have a few trees that turn yellow or red, but this year it seems we are getting a lot of brown. 

 

Don

Actually, this cluster of trees is a bit of an exception as we've been experiencing a bit of disappointment on the full display this year. There are still a good number of trees almost still green, with some early birds leafless, and still a sad majority that turned albeit with lots of mottled patches of brown. I am not entirely sure why this is the case more so this year (temperature, rainfall?). This might be a more widespread phenomenon as I've heard similar from elsewhere. Perhaps our friends out on the eastern seaboard could tell us if the fall colours are a bit washed out this year or not.

[Shamalama]

24 minutes ago, Kane said:

 

 

 

This shell reminds me of a Douvillina inaequistriata like what I find in the Centerfield mbr. of the Ludlowville fm. and Hungry Hollow Mbr. of the Widder Fm.   

 

[FossilDAWG]

My guess is that it involves some sort of conflicting information between day length and temperature.  More specifically, short day length is not being accompanied by cold (even freezing) nighttime temperatures, so the trees are getting mixed signals that interfere with the production of colored anthocyanins or the scavenging of chlorophyll/proteins from the leaves.  That's just a guess though.

 

Don

[Peat Burns]

Nice Leptaena!

[Nimravis]

Nice finds and colors.

[PyritizeMe]

Last image reminds me of a platyceras , or some form of gastropod , just from the shape and the way the shell preservation tends to occur . I believe most of that stone is Dundee formation limestone.

[ynot]

Glad You could get out to enjoy the day, before the white blanket of winter sets in.

[Kane]

Thanks, all. As I said, no new surprises on this visit, but this site has been very kind to me this year, and it was lovely to be in my element.

16 hours ago, PyritizeMe said:

 I believe most of that stone is Dundee formation limestone.

Well, therein lies the rub. The imported fill comes from a wide variety of locations, and so I've pulled trilobites from the Bois Blanc Fm (Anchiopsis anchiops, Trypaulites erinus), Amherstburg Fm (Mannopyge halli), one example each on the same shale of Pseudogygites latimarginatus and Triarthrus sp. and even Eldredgeops rana that span more than one formation. The Dundee has no exposures in my area (nearest being over 30 minutes north in St Marys via their quarry) or the odd rock or two with glacial till along the Thames River. Dundee Fm rocks are present (yet not common as they are very deep under the till), but these particular ones pictured may not actually be from this formation (one of the clues is grain size, and some of the index fossils). 

[Fossildude19]

Even your fossils have fall colors up north!  

Nice finds for a short jaunt.   

 

[PyritizeMe]

7 hours ago, Kane said:

Thanks, all. As I said, no new surprises on this visit, but this site has been very kind to me this year, and it was lovely to be in my element.

Well, therein lies the rub. The imported fill comes from a wide variety of locations, and so I've pulled trilobites from the Bois Blanc Fm (Anchiopsis anchiops, Trypaulites erinus), Amherstburg Fm (Mannopyge halli), one example each on the same shale of Pseudogygites latimarginatus and Triarthrus sp. and even Eldredgeops rana that span more than one formation. The Dundee has no exposures in my area (nearest being over 30 minutes north in St Marys via their quarry) or the odd rock or two with glacial till along the Thames River. Dundee Fm rocks are present (yet not common as they are very deep under the till), but these particular ones pictured may not actually be from this formation (one of the clues is grain size, and some of the index fossils). 

Page 1 image 8-9 look like dundee , page 2 image 3,4,8 and probably more , but hard to say. Just going off memory but as we both know formations can take many shapes sizes and colors and consistencies.