Showing posts with label trips. Show all posts
Showing posts with label trips. Show all posts

Sunday, April 28, 2024

UPPER CRETACEOUS MOTORCROSS SITE: VANCOUVER ISLAND

Steller's Jay, Cyanocitta stelleri
One of the classic Vancouver Island fossil localities is the Santonian-Maastrichtian, Upper Cretaceous Haslam Formation Motocross Pit near Brannen Lake, Nanaimo, British Columbia, Canada.

The quarry is no longer active as such though there is a busy little gravel quarry a little way down the road closer to Ammonite falls near Benson Creek Falls.

Today it is an active motocross site and remains one of the classic localities of the Nanaimo Group. We find well-preserved nautiloids and ammonites — Canadoceras, Pseudoschloenbachia, Epigoniceras — the bivalves — Inoceramus, Sphenoceramus— gastropods, and classic Nanaimo Group decapods — Hoploparia, Linuparus. We also find fossil fruit and seeds which tell the story of the terrestrial history of Vancouver Island.

Upper Cretaceous Haslam Formation Motocross Pit near Brannen Lake
It was John Fam, Vice-Chair, Vancouver Island Paleontological Society (VanPS), who originally told me about the locality. John is one of the most delightful and knowledgeable people you'd be well-blessed to meet.

While he lived on Vancouver Island, he was an active member of the VanPS back when I was Chair. Several of the best joint VIPS/VanPS paleontological expeditions were planned with or instigated by his passion for fossils. I tip my hat to him for his passion and shared love of all things paleo.

John grew up 15 minutes from the motocross locality and used to collect there a few times a week with his father. John has wonderful parents and since marrying his childhood sweetheart, the amazing Grace, those excellent genetics, curiosity and love of fossils are now being passed to a new generation. It's lovely to see John and Grace continuing tradition with two boys of their own.

I met John way back then and did an overnight at his parent's house the Friday before a weekend field trip to Jurassic Point. It was a joy to have him walk me through his collections and tell his stories from earlier years. After learning about the site from John, I headed up to the Motocross Pit with my Uncle Doug. He was a delightful man who grew up on the coast and had explored much of it but not the fossil site just 10-minutes from his home. It was wonderful to walk through time with him so many years ago and then again solo this past year with sadness in my belly that one of the best I've ever known has left this Earth.

Upper Cretaceous Haslam Formation Motocross Pit near Brannen Lake
There were some no trespassing signs up but no people around, so I walked the periphery looking for the bedrock of the Haslam.

The rocks we find here were laid down south of the equator as small, tropical islands. They rode across the Pacific heading north and slightly east over the past 80 million years to where we find them today.

Jim Haggart and Peter Ward have done much to increase our understanding of the molluscan fauna of the Nanaimo Group. Personally, both personify the charming Indiana Jones school of rugged manly palaeontologists you picture in popular film. Professionally, their singular contributions and collaborative efforts have helped shape our understanding of the correlation of Nanaimo Group fauna to those we find in the Gulf Islands of British Columbia and down in the San Juan Islands of Washington State.

Their work builds on the work of Usher (1952), Matsumoto (1959a, 1959b) and Mallory (1977). A healthy nod goes out to the work of Muller and Jeletzky (1970) for untangling the lithostratigraphic and biostratigraphic foundation for our knowledge of the Nanaimo Group.

Candoceras yokoyama, Photo: John Fam, VanPS
As I walked along the bedrock of the Haslam, a Steller's Jay, Cyanocitta stelleri, followed me from tree to tree making his guttural shook, shook, shook call. Instructive, he seemed to be encouraging me, timing his hoots to the beat of my hammer. Vancouver Island truly has glorious flora and fauna.

Fancy some additional reading? Check out a paper published in the Journal of Paleontology back in 1989 by Haggard and Ward on new Nanaimo Group Ammonites from British Columbia and Washington State.

In it, they look at the ammonite species Puzosia (Mesopuzosia) densicostata Matsumoto, Kitchinites (Neopuzosia) japonicus Spath, Anapachydiscus cf. A. nelchinensis Jones, Menuites cf. M. menu (Forbes), Submortoniceras chicoense (Trask), and Baculites cf. B. boulei Collignon are described from Santonian--Campanian strata of western Canada and northwestern United States.

Stratigraphic occurrences and ranges of the species are summarized and those taxa important for correlation with other areas in the north Pacific region and Late Cretaceous ammonite fauna of the Indo-Pacific region. Here's the link: https://www.jstor.org/stable/1305358?seq=1

Peter Ward is a prolific author, both of scientific papers and more popularized works. I highly recommend his book Gorgon: Paleontology, Obsession, and the Greatest Catastrophe in Earth's History. It is an engaging romp through a decade's research in South Africa's Karoo Desert.

Photo: Candoceras yokoyamai from Upper Cretaceous Haslam formation (Lower Campanian) near Nanaimo, British Columbia. One of the earliest fossils collected by John Fam (1993). Prepared using only a cold chisel and hammer. Photo & collection of John Fam, VIPS.

Wednesday, April 24, 2024

CHUCKANUT DRIVE: EOCENE TROPICAL PARADISE

A trip along Chuckanut Drive, in northwestern Washington is a chance to view incredible diversity from sea to sky.

An amazing array of plants and animals call this coastline home. 

For the fossil enthusiast, it is a chance to slip back in time and have a bird’s eye view of a tropical paradise preserved in the Eocene strata of various fossil sites. 

Snug up against the Pacific Ocean, this 6000m thick exposure yields a vast number of tropical and flowering plants that you might see in Mexico today. Easily accessible by car, this rich natural playground makes for an enjoyable daytrip just one hour south of the US Border.

Over vast expanses of time, powerful tectonic forces have massaged the western edge of the continent, smashing together a seemingly endless number of islands to produce what we now know as North America and the Pacific Northwest. Intuition tells us that the earth’s crust is a permanent, fixed outer shell – terra firma.

Aside from the rare event of an earthquake or the eruption of Mount St. Helen’s, our world seems unchanging, the landscape constant. In fact, it has been on the move for billions of years and continues to shift each day. As the earth’s core began cooling, some 4.5 billion years ago, plates, small bits of continental crust, have become larger and smaller as they are swept up in or swept under their neighboring plates. 

Large chunks of the ocean floor have been uplifted, shifted and now find themselves thousands of miles in the air, part of mountain chains far from the ocean today or carved by glacial ice into valleys and basins.

Two hundred million years ago, Washington was two large islands, bits of continent on the move westward, eventually bumping up against the North American continent and calling it home. Even with their new fixed address, the shifting continues; the more extreme movement has subsided laterally and continues vertically. 

The upthrusting of plates continues to move our mountain ranges skyward – the path of least resistance. This dynamic movement has created the landscape we see today and helped form the fossil record that tells much of Washington’s relatively recent history – the past 50 million years.

Chuckanut Drive is much younger than other parts of Washington. The fossils found there lived and died some 40-55 million years ago, very close to where they are now, but in a much warmer, swampy setting. The exposures of the Chuckanut Formation were once part of a vast river delta; imagine, if you will, the bayou country of the Lower Mississippi. The siltstones, sandstones, mudstones and conglomerates of the Chuckanut Formation were laid down about 40-54 million years ago during the Eocene epoch, a time of luxuriant plant growth in the subtropical flood plain that covered much of the Pacific Northwest.

This ancient wetland provided ideal conditions to preserve the many trees, shrubs & plants that thrived here. Plants are important in the fossil record because they are more abundant and can give us a lot of information about climate, temperature, the water cycle and humidity of the region. 

The Chuckanut flora is made up predominantly of plants whose modern relatives live in tropical areas such as Mexico and Central America. If you are interesting in viewing a tropical paradise in your own backyard, look no further than the Chuckanut. 

Images and tag lines: Glyptostrobus, the Chinese swamp cypress, is perhaps the most common plant found here. Also abundant are fossilized remains of the North American bald cypress, Taxodium; Metasequoia (dawn redwood), Lygodium (climbing fern), large Sabal (palm) and leaves from a variety of broad leaf angiosperm plants such as (witch hazel), Laurus (laurel), Ficus (fig) and Platanus (sycamore), and several other forms.

While less abundant, evidence of the animals that called this ancient swamp home are also found here. Rare bird, reptile, and mammal tracks have been immortalized in the outcrops of the Chuckanut Formation. Tracks of a type of archaic mammal of the Orders Pantodonta or Dinocerata (blunt foot herbivores), footprints from a small shorebird, and tracks from an early equid or webbed bird track give evidence to the vertebrates that inhabited the swamps, lakes and river ways of the Pacific Northwest 50 million years ago.

The movement of these celebrity vertebrates was captured in the soft mud on the banks of a river, one of the only depositional environments favorable for track preservation.

Friday, February 16, 2024

UPTHRUSTING PLATES: WASHINGTON GEOLOGY

Two hundred million years ago, Washington was two large islands, bits of the continent on the move westward, eventually bumping up against the North American continent and calling it home. The shifting continues, subtly changing the landscape like a breath. We only notice when pockets of resistance manifest as earthquakes, some newsworthy, some all but unnoticed. For now, the more extreme movement has subsided laterally and continues vertically, pushing California towards the North Pole. Hello Baja-BC.

The upthrusting of plates move our mountain ranges skyward – the path of least resistance. And it is this dynamic movement that's created the landscape we see today.

The 3,000 meters of the stratigraphic section of the Chuckanut Formation along Chuckanut Drive span an age range of just a few million years. The lower part is late Paleocene with a radiometric age of around 56 million years. The upper part of the section is early Eocene. The fossils found here lived and died very close to where they are now but in a much warmer, wetter, swampy setting. The exposures of the Chuckanut Formation were once part of a vast river delta; imagine, if you will, the bayou country of the Lower Mississippi. The siltstones, sandstones, mudstones and conglomerates of this formation were laid down during a time of luxuriant plant growth in the subtropical flood plain that covered much of the Pacific Northwest.

This ancient wetland provided ideal conditions to preserve the many trees, shrubs and plants that thrived here giving us a lot of information about climate, temperature, the water cycle and humidity of the region. The Chuckanut flora is made up predominantly of plants whose modern relatives live in tropical areas such as Mexico and Central America. While less abundant, evidence of the animals that called this ancient swamp home are also found here. Rare bird, reptile, and mammal tracks have been immortalized in the outcrops of the Chuckanut Formation.

Sumas Eocene Shorebird Trackway
Tracks of a type of archaic mammal of the Orders Pantodonta or Dinocerata (blunt foot herbivores), footprints from a small shorebird, and tracks from an early equid or webbed bird track give evidence to the vertebrates that inhabited the swamps, lakes and riverways of the Pacific Northwest 50 million years ago.

Fossil mammals and bird trackways from Washington State have caused great excitement over the past few years. Many new trackways have been discovered since the 2009 slides near Sumas. George Mustoe and team collected these important finds, bringing them to the Burke Museum in Washington State to study and make available for display.

The movement of these vertebrates was captured in the soft mud on the banks of an ancient river, one of the only depositional environments favourable for track preservation. The terrestrial paleontological record of Washington State at sites like Chuckanut and Racehorse Creek (U-Pb 53 Ma.) is primarily made up of plant material with some wonderfully enticing mammal, shorebird (seen here) and large Diatryma bird tracks on rare occasions.

Monday, October 3, 2022

FOSSIL HUNTING: NOT FOR THE FAINT OF HEART

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.

Monday, July 5, 2021

PTEROSAURS OF HORNBY ISLAND

If you could travel through time and go back to observe our ancient skies, you would see massive pterosaurs — huge, winged flying reptiles of the extinct order Pterosauria — cruising along with you. They soared our skies during most of the Mesozoic — from the late Triassic to the end of the Cretaceous (228 to 66 million years ago). 

By the end of the Cretaceous, they had grown to giants and one of their brethren, Quetzalcoatlus, a member of the family Azhdarchidae, boasts being the largest known flying animal that ever lived. They were the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger.

We divide their lineage into two major types: basal pterosaurs and pterodactyloids. Basal pterosaurs (also called 'non-pterodactyloid pterosaurs' or ‘rhamphorhynchoids’) were smaller animals with fully toothed jaws and long tails. Their wide wing membranes connected to their hind legs. This would have allowed them some manoeuvrability on the ground, but with an awkward sprawling posture. They were better climbers with flexible joint anatomy and strong claws. Basal pterosaurs preferred to dine on insects and small vertebrates.

Later pterosaurs (pterodactyloids) evolved many sizes, shapes, and lifestyles. Pterodactlyoids had narrower wings with free hind limbs, highly reduced tails, and long necks with large heads. On the ground, pterodactyloids walked better than their earlier counterparts, manoeuvring all four limbs smoothly with an upright posture. They walked standing plantigrade on the hind feet and folding the wing finger upward to walk on the three-fingered "hand." These later pterosaurs were more nimble. They could take off from the ground, run and wade and swim. Their jaws had horny beaks and some of these later groups lacked the teeth of earlier lineages. Some groups developed elaborate head crests that were likely used to attract mates' sexy-pterosaur style.

So can we or have we found pterosaurs on Hornby Island? The short answer is yes.

Collishaw Point, known locally as Boulder Point, Hornby Island
Hornby Island is a lovely lush, island in British Columbia's northern Gulf Islands. It was formed from sediments of the upper Nanaimo Group which are also widely exposed on adjacent Denman Island and the southern Gulf Islands.

Peter Mustard, a geologist from the Geologic Survey of Canada, did considerable work on the geology of the island. It has a total stratigraphic thickness of 1350 m of upper Nanaimo Group marine sandstone, conglomerate and shale. 

These are partially exposed in the Campanian to the lower Maastrichtian outcrops at Collishaw Point on the northwest side of Hornby Island. Four formations underlie the island from oldest to youngest, and from west to east: the Northumberland, Geoffrey, Spray and Gabriola.

During the upper Cretaceous, between ~90 to 65 Ma, sediments derived from the Coast Belt to the east and the Cascades to the southeast poured seaward to the west and northwest into what was the large ancestral Georgia Basin. This major forearc basin was situated between Vancouver Island and the mainland of British Columbia. The rocks you find here originated far to the south in Baja California and are the right age and type of sediment for a pterosaur find. But are we California dreaming?

Upper Cretaceous Nanaimo Group Fossil Concretion
Well, truth be told, we were with one of the potential pterosaur finds from Hornby. It wasn't just hopeful thinking that had the west coast in a paleo uproar many ago when Sharon Hubbard of the Vancouver Island Palaeontological Society found what looked very much like a pterosaur.

Right time period. Right location. And, we have found them here in the past.

Sandy McLachlan found the first definitive pterosaur, an azhdarchid, back in 2008.

But was Sharon's find a pterosaur?

Victoria Arbour, a Canadian evolutionary biologist and palaeontologist working as a Natural Sciences and Engineering Research Council of Canada postdoctoral fellow at the University of Toronto and Royal Ontario Museum, certainly thought so. 

While Arbour is an expert on ankylosaurs, our lumbering armoured dinosaurs friends, she has studied pterosaurs and participated in the naming of Gwawinapterus from Hornby Island. 

But here's the thing — bony material encased in stone and let to cement for millions of years can be tricky.

While this fossil find was initially described as a very late-surviving member of the pterosaur group Istiodactylidae, further examination cast doubt on the identification. Once more detail was revealed the remains were published as being those of a saurodontid fish, an ambush predator with very sharp serrated teeth and elongate, torpedo-like bodies that grew up to two meters. Not a pterosaur but still a massively exciting find. Arbour was very gracious at the renaming, taking it in stride. She has since gone on to name a partial ornithischian dinosaur from Sustut Basin, as well as the ankylosaurs Zuul, Zaraapelta, Crichtonpelta, and Ziapelta. But she may have another shot at a pterosaur.

Dan Bowen, Chair, VIPS. Photo: Deanna Steptoe Graham
In 2019, Dan Bowen, Chair of the Vancouver Island Palaeontological Society and a truly awesome possum, found some very interesting bones in concretion on Hornby. 

The concretion was nestled amongst the 72 million-year-old grey shales of the Northumberland Formation, Campanian to the lower Maastrichtian, part of the Cretaceous Nanaimo Group from Collishaw Point.

The site is known as Boulder Point to the locals and it has been a popular fossil destination for many years. It is the same site where Sharon made her find years earlier.

The concretion contains four articulated vertebrae that looked to be fish at first glance. Jay Hawley, a local fossil enthusiast was asked to prep the block to reveal more details. Once the matrix was largely removed the vertebrae inside were revealed to be bird bones, not fish and not another saurodontid as originally thought. Palaeontologist Victoria Arbour was called back in to put her keen lens on the discovery. 

You will appreciate that she took a good long look at the specimen and confirmed it to be a bird or a pterosaur. We still do not have confirmation on which it is as yet. The delicate bony material is very flattened with a very shallow u-shape on the bottom but will need additional study to confirm if the skies above California were once home to a great pterosaur who died, was fossilized then rode our tectonic plates to now call Hornby home. It is a great story and one that I am keen to follow.

References: To learn more about the azhdarchid remains found by Sandy McLachlan, check out the paper by Martin-Silverston et al. 2016.