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Where Can I Find a KT Boundary Sample in BC?


JoshIsHereForScience

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JoshIsHereForScience

Hi everyone! I'm new to this site and topic but I am very interested!

I live in Vancouver, BC and I would love to find the KT boundary and take a small sample.

Is there anywhere within a few hours driving distance from Vancouver that the KT boundary is visible and accessible?

Thank you for the help!!

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Unless "a few hours" means 12-16 hours, I don't think Raggedy Man's link will help.

There are no sites anywhere near Vancouver where the contact has been found. It is conceivable that the highest formations of the Cretaceous Nanaimo Group on Vancouver Island/Gulf Islands/Hornby Island may get up into the Paleocene, but these upper beds are unfossiliferous conglomerates or coarse clastics and no identifiable Cretaceous/Paleocene boundary has ever been recognized. Basically, you have Campanian fossiliferous beds of the Northumberland Formation (on Hornby) and the Gabriola (on Saturna as I recall), succeeded by massive conglomerates of the Geoffrey Formation (no fossils). There are fossil-bearing Eocene rocks in the area, such as the Via Appia beds near Campbell River on Vancouver Island, but their relationship with the underlying Cretaceous is unclear as no contact is exposed. Basically most or all of the Maastrichtian, all of the Paleocene, and the lower Eocene are missing or perhaps are represented by unfossiliferous sandstone and conglomerate.

Don

Edited by FossilDAWG
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KT or more properly KPg could be any deposit in which Paleogene sits upon Cretaceous rocks for example Eocene on top of Campanian. If you want to sample the impact iridium layer you would need beginning Danian overlying end Maastrichtian .

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KT or more properly KPg could be any deposit in which Paleogene sits upon Cretaceous rocks for example Eocene on top of Campanian. If you want to sample the impact iridium layer you would need beginning Danian overlying end Maastrichtian .

All completely true of course. I assumed the OP was referring to a conformable contact, likely with the iridium layer. However, even if they were happy with an unconformable contact with the last 5 million years of the Cretaceous and the first 20 million years of the Paleogene missing, I am not aware of such an exposure anywhere in southwestern BC.

Somehow this discussion reminds me of some outcrops near Ottawa Ontario where middle Ordovician limestone sits on Proterozoic metamorphic rocks. It's remarkable to think that the contact between the two represents more than a billion years!

Don

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KT or more properly KPg could be any deposit in which Paleogene sits upon Cretaceous rocks for example Eocene on top of Campanian. If you want to sample the impact iridium layer you would need beginning Danian overlying end Maastrichtian .

I disagree... the reference to KT Boundary (see title of original post) means a steady deposit through the event...iridium or not. Eocene sitting on top of late Cret is not a KT boundary. It is just an unconformity.

And on a different note, once you start defining it by the presence of iridium, you are identifying the iridium layer, not the change in fauna, which is what defines the KT boundary. Of course the boundary is defined by marine microfossils, so you gotta have different definitions in terrestrial deposits. In North American terrestrial deposits the boundary is marked by the last dinosaur and the first Paleocene mammals. These are related to deposits in Europe where the marine and the terrestrial intertongue. This is where you can start looking for iridium layers, but before we knew about the iridium spike, the boundary was generally pretty vague.

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