The Buller Creek Devonian Reef

Hoodoos

Looking up at the hoodoos from North Buller Creek.

W

ent up Buller Creek recently, not to Buller Pass, North Buller Pass, Red Peak  or any other mountain. We trudged all the way up the north fork to look at rocks. For years, our geologist friend Gord had been urging us to visit this particular Devonian  reef, some of which are reservoirs for oil and gas, though not this one.

A few comments first. At the new bridge over Buller Creek we crossed the proposed  line of the High Rockies Trail at red pin flags. There’s also a connector from farther back along the trail. Looks terrible ground to run a trail along, all mossy and bumpy with deadfall. Farther on, the arnicas were in full flower among the black trees of the burn set a few years ago. The burn extends to treeline and eastwards at a higher level to the T-junction of Buller Pass and North Buller Pass trails. This definitely lessens the scenic attraction  of the waterfall and pool just before the junction.

Arnicas in the burn.

Arnicas in the burn.

Fall and pool below the junction (left) and fall in the north fork

Fall and pool below the junction (left) and fall in the north fork

Leaving the burn behind, we walked up North Buller Pass trail, and after passing the waterfall  headed up the scree of the left hillside to cliffs and oddly-shaped hoodoos of dark grey and  brown limestone of the late Devonian Cairn Formation. Close up, the rock is riddled with windows Gord says were likely pockets of organic material that naturally weathered out, a little different to the windows we usually see that have been eroded out by rain and frost. Spent a couple of hours lurching around on loose stuff between hoodoos admiring in situ examples of amphiporas which were invertebrates that grew in “thickets in quiet back-reef lagoons” when the future Alberta was located close to the equator and the climate was tropical. They are a form of Stromatoporoids, now known to belong to the sponge family.  It was interesting to learn that late in the Devonian, a catastrophe of some kind — the latest thought is that it was a meteorite strike — wiped out many of the invertebrates that perhaps perished from lack of oxygen in the water.

One last comment. The scree we were lurching around on was loaded with fossils—nearly every rock exhibited amphipora or corals.  But there is no need to climb that high; the fossiliferous scree extends down into the trees, even into the creekbed.

Take a look at the excellent book Alberta beneath our feet: The Story of Our Rocks and Fossils, editor Brian Hitchon, publisher Geoscience Publishing. The book is  out of print, but available at 9 libraries in Calgary.

Hoodoo

Hoodoo

Amphipora in situ.

Amphipora in situ.

Amphipora in scree

Amphipora in scree

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3 comments… add one
  • Gillean Daffern Aug 4, 2015, 9:01 pm

    Thanks Neil and Adam. I’ll have to get Gord to reply on this!!! Meanwhile I am adding more info from your email Adam, which I think people will be interested in.

    “ I worked a section above where you folks were back in 1980, but the Cairn on Buller is a real conundrum. It is not typical Cairn facies – like you see at Grassi Lakes, where it is essentially all stromatoporoid biostrome (reef). No. The Buller Cairn has an amazing amount of coral material in it … in just this one area. Corals usually grow in deeper water than stromatoporoids, so the paleo-enviroment here must have been quite different. WHY is the real question … probably a good MSc. thesis in the waiting.

  • Adam Hedinger Jul 31, 2015, 9:02 pm

    Completely agree with the comments made by Nigel Watts. In the first photo entitled “Amphipora in situ”
    what we have in the upper left hand corner is laminar (platy) stromatoporoids overlying robust branching corals. There may be some Amphipora debris in the lower right hand corner. In the photo entitled “Amphipora in scree” … these are robust branching corals.

  • Nigel Watts Jul 31, 2015, 1:26 pm

    I don’t think the large stem like fossils are Amphipora, to me they look like the colonial rugose coral of the Family Disphyllidae. The branching genus Disphyllum is the most diverse and common. Typically Amphipora consist of tubes and branches that are a few mm in diameter.

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