Geological Time Question

[EscarpmentMary]

The weather is turning here in Ontario Canada, leaves are raked, stuff is stored safely away, waiting for the lake effect snow. Went for a walk along the lake and well couldn’t resist this rock.

Here is my question:  In geological time, what do you all think is the top and what is the bottom?

Is the limestone newer or older than the layered what I believe is silicate.

Every rock tells me a story, I see the impact of multi cell animals, and what I believe is the heavy tidal action of the Silurian sea because of heavy gravity interaction of earth and moon, cephalopods, bivalves, …….!!

 

 

[Coco]

@Tidgy's Dad

 

Brachiopods ?

 

Coco

[Tidgy's Dad]

Definitely brachiopods. 

Probably strophomenids.

I think Rafinesquina alternata. 

[Fossildude19]

This isn't an ID request, but a question.

I have edited the post to make that more clear, and bring the text to the top. 

[Ludwigia]

3 hours ago, EscarpmentMary said:

Here is my question:  In geological time, what do you all think is the top and what is the bottom?

 

If you mean around Owen Sound, then Silurian is younger than Ordovician, so it would normally be found at the top unless it's been tectonically uplifted and turned over, but I don't think that there are any such occurrences in your area. Along the coast in that area and to the east is mostly Ordovician. Silurian is more inland and to the west and north. Exactly where along the Lake (Georgian Bay?) did you take your walk and find these things?

[EscarpmentMary]

I really haven't posted in a while, sorry if I was not clear, the rock had been washed up out of the Owen Sound Bay so in fact I see the different layers but I think yes, Ordovician then Silurian and so would think the limestone layer would be on the bottom then the upper layers would be the silicate on top.  On the top however  is a beautiful imprint of a brachiopod  but limestone came first is what you are saying. I love your thought of the tectonic plate rolling on top of itself, I have never thought about that but this plate did start south of the equator. I have lived here along the west shore of Owen Sound Bay for 30 years, sitting along side of the Niagara Escarpment, every shovel of dirt, every walk along the shoreline reveals fossils of the ancient reef. it is amazing, The North American Aboriginal peoples creation story says North America is a turtle swimming the seas. I will post a picture after. If you look at the Owen Sound Bay and turn the map to line the bay up in an east, west axis, I have a hypothesis that the ancient tides coming from the west carved out this bay before the ancient glaciers from the north east., One thousand meter high walls of water crashing over the old reef and on down. This is all musings, it is nice to have a place for such things.  

[Top Trilo]

I believe the question points to this particular specimen. What layer is newest and what's oldest? I've often wondered the same thing on some of mine.

[EscarpmentMary]

[Kane]

Keep in mind that the lithology can differ significantly even within a geologic period pending sea level and available materials at deposition. So it is entirely possible to see, for example, alternating sequences of limestone, dolostone, and calcareous shales in the Silurian.

[EscarpmentMary]

The above photos show an actual representation of the creation story by an artist from the Saugeen Ojibwa Nation, I also posted the photo from Tobermory showing land formations that say ancient tidal action to me anyways, that photo was taken around the 1900’s. I just happened to have it in my photo files.