Saturday, 12 August 2023

MEMEKAY RIVER FOSSIL BOUNTY

Coroniceras sp. from Sayward, British Columbia
This yummy Lower Jurassic ammonite with the creamy dark chocolate colouring is from an all but inaccessible outcrop of the Upper Sinemurian, Bonanza Group,  Harbledownense Zone, Memekay River area, near Sayward, Vancouver Island, British Columbia, Canada. 

This area is home to the We Wai Kai and Wei Wai Kum First Nations and lands of the K'omoks whose culture thrives and reflects the natural rugged beauty of the central island region.

I passed through Sayward earlier this month on the way to northern Vancouver Island. 

It is rugged, remote and beautiful. Think trees and valleys for as far as the eye can see. Some of those hillsides on the horizon contain wonderful fossils, including this Coroniceras sp. with the truly marvellous keel.

By the time these ammonites were being buried in sediment, Wrangellia, the predominately volcanic terrane that now forms Vancouver Island and Haida Gwaii, had made its way to the northern mid-latitudes.

Within the basal part of the sequence, sedimentary beds are found interbedded with lapilli and crystal tuffs. Here you'll see maroon tuffaceous sandstone, orange-grey sandstone, granule sandstone and conglomerate. Within them we find ammonites nestled in with gastropods and pelecypods. 

While the fossiliferous outcrop is quite small, the Bonanza group is much larger, estimated to be at least 1000 metres thick. The site is quite small and in an active logging area, so the window to collect was limited. The drive up the mountain was thrilling as there had just been heavy rains and the road was washed out and narrowed until it was barely the width of our wheelbase and very, very steep. Closer to the top it narrowed to be just shy of the width of the vehicle — thrilling, to say the least. 

So scary that my passengers all got out as there was a high probability of going head-first over the edge. I was navigating by some handwritten field notes and a wee map on a paper napkin that should have read, "park at the bottom and hike up." 

Did we park at the bottom and hike up? No, we did not. 

The torrential rains of the Pacific Northwest had been working their magic on the hillside and slowly washing out the road until it slowly became more of a trail.

At the base of the hillside all looked well. Giddy for the fossils to come, we ventured off with a truck full of enthusiasm. Within 15 minutes of steep elevation gain, we had a wonderful view of the valley below. We were halfway up the mountain before I realized the error of my ways. The road twisted and turned then slowly narrowed to the width of my tires. Too narrow to turn around, so the only way was up. 

Graham Beard from Qualicum Beach was the fellow who showed me the site and drew the wee map for me. I cannot recall everyone on the trip, but Perry Poon was there — he shot a video of the drive up that he described as thrilling. I have never seen it but would like to one day — and so was Patricia Coutts with her lovely Doberman. 

She and I had just done a trip up to Goldbridge where the cliff we were on had turned into a landslide into a ravine so she was feeling understandably cautious about the power of Mother Nature. 

Picture the angle, the hood of my jeep riding high and hiding what remained of the road beneath and a lovely stick shift that made you roll backwards a wee bit with every move to put it into gear. So, without being able to see the very narrow path beneath, I had to just keep going. 

Both Perry and Patricia helped with filling in the potholes so my tires would have something to grip. 

I bent the frame on the jeep heading up and had some explaining to do when I returned it to the car rental place. 

As I recall, I wasn't in my ordinary vehicle but a rental because my car had been stolen the weekend before when I was away with John Fam and Dan Bowen collecting at Jurassic Point, an epic fossil site accessible only by boat on our wild west coast.

Fortuitous timing really, as they stole my car but I had unloaded my precious fossil collecting gear out of the trunk just days before.  

In the end, we found what we were looking for. Memekay yields a mix of ammonites, gastropods and bivalves. 

Many of them are poorly preserved. It was a hell of a ride but well worth the effort as we found some great fossils and with them more information on the palaeontology and geology of Vancouver Island. Just look at the keel on this beauty.

I would share the site information but it is now covered over with debris and inaccessible. One day, this whole region will be developed and the site will be opened up again. Until then, we'll have to enjoy what has been unearthed.