Showing posts with label collecting. Show all posts
Showing posts with label collecting. Show all posts

Tuesday, May 14, 2024

ATURIA: MIOCENE NAUTILOID

Aturia angustata, Lower Miocene, WA
This lovely Lower Miocene nautiloid is Aturia angustata collected on the foreshore near Clallam Bay, Olympic Peninsula, northwestern Washington. 

Aturia is an extinct genus of Paleocene to Miocene nautiloid within Aturiidae, a monotypic family, established by Campman in 1857 for Aturia (Bronn, 1838), and is included in the superfamily Nautilaceae (Kümmel,  1964).

There are seven living nautiloid species in two genera: Nautilus pompilius, N. macromphalus, N. stenomphalus, N. belauensis, and the three new species being described from Samoa, Fiji, and Vanuatu (Ward et al.). We have specimens of fossil nautiloids dating to the Turonian of California, and possibly the Cenomanian of Australia. There has also been a discovery of what might be the only known fossil of Allonautilus (Ward and Saunders, 1997), from the Nanaimo Group of British Columbia, Canada.

Aturia in the Collection of Rick Ross, VIPS
The exquisite shell preservation of many Nanaimo nautilids has opened up a lens into paleotemperatures and accurate Nitrogen isotope analyses. 

Nautilus and all other known Cretaceous through Paleogene nautiloids were shallow water carnivores. We may see their shells as beautiful bits of art and science today, but they were seen in our ancient oceans as small yet mighty predators. Preferring to dine on shrimp, crab, fish and on occasion, a friendly cousin nautiloid to two.

Aturia lived in cooler water in the Cenozoic, preferring it over the warmer waters chosen by their cousins. Aturia, are commonly found as fossils from Eocene and Miocene outcrops. That record ends with their extinction in the late Miocene. This was a fierce little beast with jaws packed with piranha-like teeth. They grew at least twice that of the largest known Nautilus living today. 

Aturia is characterized by a smooth, highly involute, discoidal shell with a complex suture and subdorsal siphuncle. The shell of Aturia is rounded ventrally and flattened laterally; the dorsum is deeply impressed. The suture is one of the most complex within the subclass Nautiloidea. Of all the nautiloids, he may have been able to go deeper than his brethren.

Nautiloids are known for their simple suturing in comparison to their ammonite cousins. This simplicity of design limited their abilities in terms of withstanding the water pressure experienced when several atmospheres below the sea. Nautiloids were not able to compete with their ammonite cousins in this regard. 

Instead of elaborate and complex sutures capable of withstanding the pressures of the deep, nautiloids have simpler sutures that would have them enfold on themselves and crush at depth.  

Aturia angustata; Rick Ross Collection
It has a broad flattened ventral saddle, narrow pointed lateral lobes, broad rounded lateral saddles, broad lobes on the dorso-umbilical slopes, and a broad dorsal saddle divided by a deep, narrow median lobe. 

The siphuncle is moderate in size and located subdorsally in the adapical dorsal flexure of the septum. Based on the feeding and hunting behaviours of living nautiluses, Aturia most likely preyed upon small fish and crustaceans. 

I've found a few of these specimens along the beaches of Clallam Bay and nearby in a local clay quarry. I've also seen calcified and chalcedony — microcrystalline quartz — agatized beauties of this species collected from river sites within the Olympic Peninsula range. In the bottom photos, you can see Aturia from Washington state and one (on the stand on the left) from Oregon, USA. These beauties are in the collections of the deeply awesome Rick Ross, Vancouver Island Palaeontological Society.

References: Ward, P; Haggart, J; Ross, R; Trask, P; Beard, G; Nautilus and Allonautilus in the Nanaimo Group, and in the modern oceans; 12th British Columbia Paleontological Symposium, 2018, Courtenay, abstracts; 2018 p. 10-11

Friday, February 23, 2024

PISTA DE BAILE JURÁSICA

This busy slate grey dinosaur trackway from the Iberian Peninsula looks more like a dance floor than the thoroughfare it is. 

The numerous theropod dinosaur tracks — with a few enormous sauropod tracks thrown in for good measure — cover the entire surface. 
The local soil has a bit of rusty iron ore in it that highlights each print nicely when the soil is blown into the depressions the tracks left. 

The dinosaurs crossed this muddy area en masse sometime back in the Jurassic.

The Iberian Peninsula is the westernmost of the three major southern European peninsulas — the Iberian, Italian, and Balkan. It is bordered on the southeast and east by the Mediterranean Sea, and on the north, west, and southwest by the Atlantic Ocean. The Pyrenees mountains are situated along the northeast edge of the peninsula, where it adjoins the rest of Europe. Its southern tip is very close to the northwest coast of Africa, separated from it by the Strait of Gibraltar and the Mediterranean Sea.

The Iberian Peninsula contains rocks of every geological period from the Ediacaran to the recent, and almost every kind of rock is represented. To date, there are 127 localities of theropod fossil finds ranging from the Callovian-Oxfordian — Middle-Upper Jurassic — to the Maastrichtian (Upper Cretaceous), with most of the localities concentrated in the Kimmeridgian-Tithonian interval and the Barremian and Campanian stages. The stratigraphic distribution is interesting and suggests the existence of ecological and/or taphonomic biases and palaeogeographical events that warrant additional time and attention.

As well as theropods, we also find their plant-eating brethren. This was the part of the world where the last of the hadrosaurs, the duck-billed dinosaurs, lived then disappeared in the Latest Cretaceous K/T extinction event 65.5 million years ago.

The core of the Iberian Peninsula is made up of a Hercynian cratonic block known as the Iberian Massif. On the northeast, this is bounded by the Pyrenean fold belt, and on the southeast, it is bounded by the Baetic System. These twofold chains are part of the Alpine belt. To the west, the peninsula is delimited by the continental boundary formed by the magma-poor opening of the Atlantic Ocean. The Hercynian Foldbelt is mostly buried by Mesozoic and Tertiary cover rocks to the east but nevertheless outcrops through the Sistema Ibérico and the Catalan Mediterranean System. The photo you see here is care of the awesome Pedro Marrecas from Lisbon, Portugal. Hola, Pista de baile jurásica!

Pereda-Suberbiola, Xabier; Canudo, José Ignacio; Company, Julio; Cruzado-Caballero, Penélope; Ruiz-Omenaca, José Ignacio. "Hadrosauroid dinosaurs from the latest Cretaceous of the Iberian Peninsula" Journal of Vertebrate Paleontology 29(3): 946-951, 12 de septiembre de 2009.

Pereda-Suberbiola, Xabier; Canudo, José Ignacio; Cruzado-Caballero, Penélope; Barco, José Luis; López-Martínez, Nieves; Oms, Oriol; Ruíz-Omenaca, José Ignacio. Comptes Rendus Palevol 8(6): 559-572 septiembre de 2009.

Wednesday, October 5, 2022

TIME TRAVELLERS WANTED: EXPLORING HARRISON LAKE

Located three hours east of Vancouver, most folks head to Harrison Lake to enjoy its crisp waters, soak in the hot springs, camp or four-wheel-drive immersed in rugged scenery, or look for the elusive Sasquatch reported to live in the area. 

But there are some who come to Harrison Lake and miss the town entirely. Instead, they favour the upper west side of the lake and the fossiliferous bounty found here.

Indeed, this is the perfect location for local citizen scientists to strut their stuff. Harrison is a perfect family day trip, where you can discover wonderful marine fossil specimens as complete or partially crushed fossilized shells embedded in rock. 

It is truly amazing that we can find them at all. These beauties range in age from Jurassic to Cretaceous, with most being Lower Callovian, meaning the ammonites here swam our ancient oceans more than 160 million years ago. 

The area around Harrison Lake has been home to the Sts’ailes, a sovereign Coast Salish First Nation for thousands of years. Sts’ailes’ means, “the beating heart,” and it sums up this glorious wilderness perfectly. They describe their ancient home as Xa’xa Temexw or Sacred Earth. 

With the settling of Canada, Geologists began exploring the area in the 1880s, calling upon the Sts’ailes to help them look for coal and a route for the Canadian Pacific Railway. Coal was the aim, but happily, they also found fossils. Sacred Earth, indeed.  

Belemnite Fossils
In my favourite outcrops, you can find large, smooth inflated Jurassic ammonites along with their small grey and brown cousins. 

Further up the road, you will see Cretaceous cigar-shaped squid-like cephalopods called Belemnites, and the bivalve (clam) Buchia — gifts deposited by glaciers. Here are the most common.

Ammonites

Almost all of the ammonite specimens found near Harrison Lake are the toonie sized Cadoceras (Paracadoceras) tonniense with well-preserved outer whorls but flattened inner whorls. We find semi-squished elliptical specimens here, too. If you see a large, smooth, inflated grapefruit-sized ammonite, you are holding a rare prize — a Cadoceras comma ammonite, the macroconch or female of the species.  

Ammonites were predatory, squid-like creatures that lived inside coil-shaped shells. Like other cephalopods, ammonites had sharp, beak-like jaws inside a ring of squid-like tentacles that extended from their shells. They used these tentacles to snare prey — plankton, vegetation, fish and crustaceans — similar to the way a squid or octopus hunts today.

Within their shells, ammonites had a number of chambers called septa filled with gas or fluid, and they were interconnected through a wee air tube. By pushing air in or out, they were able to control their buoyancy. 

These small but mighty marine predators lived in the last chamber of their shell and continuously built new shell material as they grew. As they added each new chamber, they would move their squid-like body down to occupy the final outside chamber.

Interestingly, ammonites from Harrison Lake are quite similar to the ones found within the lower part of the Chinitna Formation near Cook Inlet, Alaska, and Jurassic Point, Kyuquot, on the west coast of Vancouver Island — some of the most beautiful places on Earth. 

Buchia (bivalve) Clams

The bivalve or clam Buchia are commonly found at Harrison Lake. You will see them cemented together en masse. . They populated Upper Jurassic–Lower Cretaceous waters like a team sport. When they thrived, they really thrived, building up large coquinas of material. Large boulders of Buchia cemented together en masse hitched a ride with the glaciers and were deposited around Harrison Lake. Some kept going and we find similar erratics or glacier-deposited boulders as far south as Washington state. 

Buchia is used as Index Fossils. Index fossils help us to figure out the age of the rock we are looking at because they are abundant, populate an area en masse, and then die out quickly. In other words, they make it easy to identify a geologic time span.

So what does this mean to you? Now, when you are out and about with friends and discover rocks with Buchia, or made entirely of Buchia, you can say, “Oh, this looks to be Upper Jurassic or Lower Cretaceous. Come take a look! We're likely the first to lay eyes on this little clam since dinosaurs roamed the Earth.” 

Fossil Collecting at Harrison Lake Fossil Field Trip — Getting there

This Harrison Lake site is a great day trip from Vancouver or the Fraser Valley. You will need a vehicle with good tires for travel on gravel roads. Search out the route ahead of time and share your trip plan with someone you trust. If you can pre-load the Google Earth map of the area, you will thank yourself. 

Heading east on from Vancouver, it will take you 1.5-2 hours to reach Harrison Mills. 

Access Forestry Road #17 at the northeast end of the parking lot from the Sasquatch Inn at 46001 Lougheed Hwy, Harrison Mills. From there, it will take about an hour to get to the site. Look for signs for the Chehalis River Fish Hatchery to get you started. 

Drive 30 km up Forestry Road #1, and stop just past Hale Creek at 49.5° N, 121.9° W (paleo-coordinates 42.5° N, 63.4° W) on the west side of Harrison Lake. You will see Long Island to your right. 

The first of the yummy fossil exposures are just north of Hale Creek on the west side of the road. Keep in mind that this is an active logging road, so watch your kids and pets carefully. Everyone should be wearing something bright so they can be easily spotted.

How to Spot the Fossils

The fossils here are easily collected—look in the bedrock and in the loose material that gathers in the ditches. Specimens will show up as either dark grey, grey-brown or black. Look for the large, dark-grey boulders the size of smart cars packed with Buchia. 

And while you are at it, be on the lookout for anything that looks like bone. This site is also ripe for marine reptiles—think plesiosaur, mosasaur and elasmosaur. As a citizen scientist and budding palaeontologist, you might just find something new!

What to Know Before You Go

Fill your gas tank and pack a tasty lunch. As with all trips into British Columbia's wild places, dress for the weather. You will need hiking boots, rain gear, gloves, eye protection, and a good geologic hammer and rock (cold) chisel. 

Wear bright clothing and keep your head covered. Slides are common, and you may start a few if you hike the cliffs. If you are with a group, those collecting below may want to consider hardhats in case of rockfall — chunks of rock the size of your fist up to the size of a grapefruit. They pack a punch. 

Bring a colourful towel or something to put your keepers on. Once you set rock down, it can be hard to find again given the terrain. I take the extra precaution of spraying the ends of my hammers and chisels with yellow fluorescent paint, as I have lost too many in the field. You will also want to bring a camera for the blocks of Buchia that are too big to carry home. 

Identifying Your Treasures

When you have finished for the day, compare your treasures to see which ones you would like to keep. In British Columbia, you are a steward of the fossil, which means they belong to the province, but you can keep them safe. You are not allowed to sell or ship them outside British Columbia without a permit. 

Once you get home, wash and identify your finds. Harrison Lake does not have a large variety of fossil fauna, so this should not be difficult. If your find is coiled and round, it is an ammonite. If it is long and straight, it is a belemnite. And if it looks like a wee fat baby oyster, it is Buchia. This is not always true, but mostly true.

What about collecting fossils in all seasons?. Everyone has a preference. I prefer not to collect in the snow, but I have done it. While sunny days are lovely, it can also be easier to see the specimens when the rock is wet. So, do we do this in the rain? Heck, yeah! 

In torrential rain? 

Yes — once you are hooked, but for your casual friends or the kiddos, the answer is likely no. Choose your battles. They may come with you, but a cold day getting soaked is no fun. 

In time, you will find your inner fossil geek — probably with your first find. And that's just the tip of the iceberg. First, it will be you, then your kids, your friends and then your neighbour. Once you start, it is easy to get hooked. Fossil addiction is real, and the only cure is to get out there and do it some more. You've got this!

References and further information:

A. J. Arthur, P. L. Smith, J. W. H. Monger and H. W. Tipper. 1993. Mesozoic stratigraphy and Jurassic palaeontology west of Harrison Lake, southwestern British Columbia. Geological Survey of Canada Bulletin 441:1-62

R. W. Imlay. 1953. Callovian (Jurassic) ammonites from the United States and Alaska Part 2. The Alaska Peninsula and Cook Inlet regions. United States Geological Survey Professional Paper 249-B:41-108

An overview of the tectonic history of the southern Coast Mountains, British Columbia; Monger, J W H; in, Field trips to Harrison Lake and Vancouver Island, British Columbia; Haggart, J W (ed.); Smith, P L (ed.). Canadian Paleontology Conference, Field Trip Guidebook 16, 2011 p. 1-11 (ESS Cont.# 20110248).


Thursday, April 14, 2022

SACRED EARTH: HARRISON LAKE

Located three hours east of Vancouver, most folks head to Harrison Lake to enjoy its crisp waters, soak in the hot springs, camp or four-wheel-drive immersed in rugged scenery, or look for the elusive Sasquatch reported to live in the area. 

But there are some who come to Harrison Lake and miss the town entirely. Instead, they favour the upper west side of the lake and the fossiliferous bounty found here.

Indeed, this is the perfect location for local citizen scientists to strut their stuff. Harrison is a perfect family day trip, where you can discover wonderful marine fossil specimens as complete or partially crushed fossilized shells embedded in rock. 

It is truly amazing that we can find them at all. These beauties range in age from Jurassic to Cretaceous, with most being Lower Callovian, meaning the ammonites here swam our ancient oceans more than 160 million years ago. 

The area around Harrison Lake has been home to the Sts’ailes, a sovereign Coast Salish First Nation for thousands of years. Sts’ailes’ means, “the beating heart,” and it sums up this glorious wilderness perfectly. They describe their ancient home as Xa’xa Temexw or Sacred Earth. 

With the settling of Canada, Geologists began exploring the area in the 1880s, calling upon the Sts’ailes to help them look for coal and a route for the Canadian Pacific Railway. Coal was the aim, but happily, they also found fossils. Sacred Earth, indeed.  

Belemnite Fossils
In my favourite outcrops, you can find large, smooth inflated Jurassic ammonites along with their small grey and brown cousins. 

Further up the road, you will see Cretaceous cigar-shaped squid-like cephalopods called Belemnites, and the bivalve (clam) Buchia — gifts deposited by glaciers. Here are the most common.

Ammonites

Almost all of the ammonite specimens found near Harrison Lake are the toonie sized Cadoceras (Paracadoceras) tonniense with well-preserved outer whorls but flattened inner whorls. We find semi-squished elliptical specimens here, too. If you see a large, smooth, inflated grapefruit-sized ammonite, you are holding a rare prize — a Cadoceras comma ammonite, the macroconch or female of the species.  

Ammonites were predatory, squid-like creatures that lived inside coil-shaped shells. Like other cephalopods, ammonites had sharp, beak-like jaws inside a ring of squid-like tentacles that extended from their shells. They used these tentacles to snare prey — plankton, vegetation, fish and crustaceans — similar to the way a squid or octopus hunts today.

Within their shells, ammonites had a number of chambers called septa filled with gas or fluid, and they were interconnected through a wee air tube. By pushing air in or out, they were able to control their buoyancy. 

These small but mighty marine predators lived in the last chamber of their shell and continuously built new shell material as they grew. As they added each new chamber, they would move their squid-like body down to occupy the final outside chamber.

Interestingly, ammonites from Harrison Lake are quite similar to the ones found within the lower part of the Chinitna Formation near Cook Inlet, Alaska, and Jurassic Point, Kyuquot, on the west coast of Vancouver Island — some of the most beautiful places on Earth. 

Buchia (bivalve) Clams

The bivalve or clam Buchia are commonly found at Harrison Lake. You will see them cemented together en masse. . They populated Upper Jurassic–Lower Cretaceous waters like a team sport. When they thrived, they really thrived, building up large coquinas of material. Large boulders of Buchia cemented together en masse hitched a ride with the glaciers and were deposited around Harrison Lake. Some kept going and we find similar erratics or glacier-deposited boulders as far south as Washington state. 

Buchia is used as Index Fossils. Index fossils help us to figure out the age of the rock we are looking at because they are abundant, populate an area en masse, and then die out quickly. In other words, they make it easy to identify a geologic time span.

So what does this mean to you? Now, when you are out and about with friends and discover rocks with Buchia, or made entirely of Buchia, you can say, “Oh, this looks to be Upper Jurassic or Lower Cretaceous. Come take a look! We're likely the first to lay eyes on this little clam since dinosaurs roamed the Earth.” 

Fossil Collecting at Harrison Lake Fossil Field Trip — Getting there

This Harrison Lake site is a great day trip from Vancouver or the Fraser Valley. You will need a vehicle with good tires for travel on gravel roads. Search out the route ahead of time and share your trip plan with someone you trust. If you can pre-load the Google Earth map of the area, you will thank yourself. 

Heading east on from Vancouver, it will take you 1.5-2 hours to reach Harrison Mills. 

Access Forestry Road #17 at the northeast end of the parking lot from the Sasquatch Inn at 46001 Lougheed Hwy, Harrison Mills. From there, it will take about an hour to get to the site. Look for signs for the Chehalis River Fish Hatchery to get you started. 

Drive 30 km up Forestry Road #1, and stop just past Hale Creek at 49.5° N, 121.9° W (paleo-coordinates 42.5° N, 63.4° W) on the west side of Harrison Lake. You will see Long Island to your right. 

The first of the yummy fossil exposures are just north of Hale Creek on the west side of the road. Keep in mind that this is an active logging road, so watch your kids and pets carefully. Everyone should be wearing something bright so they can be easily spotted.

How to Spot the Fossils

The fossils here are easily collected—look in the bedrock and in the loose material that gathers in the ditches. Specimens will show up as either dark grey, grey-brown or black. Look for the large, dark-grey boulders the size of smart cars packed with Buchia. 

And while you are at it, be on the lookout for anything that looks like bone. This site is also ripe for marine reptiles—think plesiosaur, mosasaur and elasmosaur. As a citizen scientist and budding palaeontologist, you might just find something new!

What to Know Before You Go

Fill your gas tank and pack a tasty lunch. As with all trips into British Columbia's wild places, dress for the weather. You will need hiking boots, rain gear, gloves, eye protection, and a good geologic hammer and rock (cold) chisel. 

Wear bright clothing and keep your head covered. Slides are common, and you may start a few if you hike the cliffs. If you are with a group, those collecting below may want to consider hardhats in case of rockfall — chunks of rock the size of your fist up to the size of a grapefruit. They pack a punch. 

Bring a colourful towel or something to put your keepers on. Once you set rock down, it can be hard to find again given the terrain. I take the extra precaution of spraying the ends of my hammers and chisels with yellow fluorescent paint, as I have lost too many in the field. You will also want to bring a camera for the blocks of Buchia that are too big to carry home. 

Identifying Your Treasures

When you have finished for the day, compare your treasures to see which ones you would like to keep. In British Columbia, you are a steward of the fossil, which means they belong to the province, but you can keep them safe. You are not allowed to sell or ship them outside British Columbia without a permit. 

Once you get home, wash and identify your finds. Harrison Lake does not have a large variety of fossil fauna, so this should not be difficult. If your find is coiled and round, it is an ammonite. If it is long and straight, it is a belemnite. And if it looks like a wee fat baby oyster, it is Buchia. This is not always true, but mostly true.

What about collecting fossils in all seasons?. Everyone has a preference. I prefer not to collect in the snow, but I have done it. While sunny days are lovely, it can also be easier to see the specimens when the rock is wet. So, do we do this in the rain? Heck, yeah! 

In torrential rain? 

Yes — once you are hooked, but for your casual friends or the kiddos, the answer is likely no. Choose your battles. They may come with you, but a cold day getting soaked is no fun. 

In time, you will find your inner fossil geek — probably with your first find. And that's just the tip of the iceberg. First, it will be you, then your kids, your friends and then your neighbour. Once you start, it is easy to get hooked. Fossil addiction is real, and the only cure is to get out there and do it some more. You've got this!

References and further information:

A. J. Arthur, P. L. Smith, J. W. H. Monger and H. W. Tipper. 1993. Mesozoic stratigraphy and Jurassic palaeontology west of Harrison Lake, southwestern British Columbia. Geological Survey of Canada Bulletin 441:1-62

R. W. Imlay. 1953. Callovian (Jurassic) ammonites from the United States and Alaska Part 2. The Alaska Peninsula and Cook Inlet regions. United States Geological Survey Professional Paper 249-B:41-108

An overview of the tectonic history of the southern Coast Mountains, British Columbia; Monger, J W H; in, Field trips to Harrison Lake and Vancouver Island, British Columbia; Haggart, J W (ed.); Smith, P L (ed.). Canadian Paleontology Conference, Field Trip Guidebook 16, 2011 p. 1-11 (ESS Cont.# 20110248).


Friday, March 4, 2022

HORNBY ISLAND: A WEALTH OF NEW FOSSIL FINDS

Pachydiscus suchiaensis ID: 18-08-CP-002
Hornby is a glorious place to collect. It is family and dog friendly. You need to dress for beach collecting preferably with rubber boots, eye protection and clothing for both sun and rain. 

I like to bring a 5-gallon bucket or hard plastic bottomed backpack for my finds. Whatever you bring is going to get wet, muddy and laced with sand. 

As well as a rock hammer, I bring a 2-4 pound sledgehammer and rock pick for collecting and cracking open the concretions here. If you are lucky, when you split them you see a fossil hidden within. 

While that is not always the case, the rewards are well-worth. One such beauty from a glorious day of collecting on Hornby is the beautiful ammonite you see here.

It is nestled amongst the seaweed and modern oysters clinging to the grey shales of the Northumberland Formation is the Upper Cretaceous (Campanian) ammonite Pachydiscus suchiaensis. This is one of my favourite species and is treasured both for its beauty and the fossil site it hails from. 

This darling was found in situ in the 72 million-year-old sediments at Collishaw Point on the northwest side of Hornby Island, southwestern British Columbia.

The island is beautiful in its own right and the fossils from here often keep some of their original shell or nacre which makes them quite fetching. This fellow is found amongst gastropods, shark teeth, fossil crabs, baculites and other bivalve fossils. 

Many of the fossils found at this locality are found in concretions rolled smooth by time and tide. The concretions you find on the beach are generally round or oval in shape and are made up of hard, compacted sedimentary rock. 

These past few years, many new and wonderful specimens have been unearthed — particularly by members of the Vancouver Island Palaeontological Society (VIPS). 

Two particular finds are jaw-droppers — a Diploceras (think one-metre long paperclip, except it is a heteromorph ammonite) longer than your arm and Actinosepia gladius — internal hard body part found in many cephalopods — of a Vampyropod, a member of the proposed group Vampyropoda — equivalent to the superorder Octopodiformes — which includes vampire squid and octopus. 

Not all of these beauties come out in one piece and as well as amazing collecting skill, the VIPS boasts some of the best Fossil Preparators in British Columbia. A nod of respect to both Jason Hawley and Rick Ross in this regard. Rick is a skilled collector and found a rather nice and rare pachydiscid ammonite at Hornby this past year that I had never seen before. It has been a good year for collecting at Collishaw Point. Another notable find was the decapod, Archaeopus vancouverensis (Woodward 1896), found by Adam Melzak this past summer. If you are looking to get out and about, fossil collecting on Hornby Island is the perfect day trip or weekend getaway.

Where to View the Fossils:

The Courtenay Museum, Qualicum Museum and Pacific Museum of the Earth have delightful collections of specimens from the Upper Cretaceous of Hornby Island. This lovely heteromorph ammonite, Nostoceras hornbyense (Whiteaves, 1895) is a classic. The photo below is courtesy of John Fam, Vice-Chair of the Vancouver Paleontological Society (VIPS) on a recent visit to poke through the collections at the Pacific Museum of the Earth. 

It is a classic example of the heteromorph specimens found at Hornby. Bob Copeman found the best Nostoceras hornbyense I have ever seen from these outcrops. Lucky for you, a replica of that specimen has been made is available to be purchased from the VIPS. Always a nice addition to the collection — especially if you keep a teaching collection where specimens need to be handled by younger, rougher hands.

Nostoceras hornbyense (Whiteaves, 1895)
The main topographic feature on Hornby Island is an arcuate mountain of the resistant cliff-forming Geoffrey formation. Near Shingle Spit about half a mile from the coast is Mt. Geoffrey 920-foot peak; from there the mountain gradually drops in elevation to the southeast and to the north.  

It is 700-feet of conglomerate in a homocline striking N 20° W and dipping to the northeast at a shallow angle of about 6°. 

The apex of the arcuate mountain belt points to the southwest. The coast of Hornby is probably a rising shoreline, as indicated by the almost perpendicular cliffs along its periphery. A hundred (100) foot cliffs of Lambert shale extends from Shingle Spit to Phipps Point, while from the latter to Boulder Point, the cliffs are not as steep and are covered in many places by vegetation.

Behind the mountain and almost enclosed by it is the fertile, green Strachan Valley. On the large peninsula which extends in a southeast direction from the north of the island towards St. John’s Point, the Hornby Formation outcrops form the cliffs on the east side of Tribune Bay. The highest of these is about 200 feet. The argillaceous Lambert and Spray formations form the subdued lowlands of the island.

Monday, January 17, 2022

FOSSIL DETECTIVES WANTED: HARRISON LAKE

Located three hours east of Vancouver, most folks head to Harrison Lake to enjoy its crisp waters, soak in the hot springs, camp or four-wheel-drive immersed in rugged scenery, or look for the elusive Sasquatch reported to live in the area. 

But there are some who come to Harrison Lake and miss the town entirely. Instead, they favour the upper west side of the lake and the fossiliferous bounty found here.

Indeed, this is the perfect location for local citizen scientists to strut their stuff. Harrison is a perfect family day trip, where you can discover wonderful marine fossil specimens as complete or partially crushed fossilized shells embedded in rock. 

It is truly amazing that we can find them at all. These beauties range in age from Jurassic to Cretaceous, with most being Lower Callovian, meaning the ammonites here swam our ancient oceans more than 160 million years ago. 

The area around Harrison Lake has been home to the Sts’ailes, a sovereign Coast Salish First Nation for thousands of years. Sts’ailes’ means, “the beating heart,” and it sums up this glorious wilderness perfectly. They describe their ancient home as Xa’xa Temexw or Sacred Earth. 

With the settling of Canada, Geologists began exploring the area in the 1880s, calling upon the Sts’ailes to help them look for coal and a route for the Canadian Pacific Railway. Coal was the aim, but happily, they also found fossils. Sacred Earth, indeed.  

Belemnite Fossils
In my favourite outcrops, you can find large, smooth inflated Jurassic ammonites along with their small grey and brown cousins. 

Further up the road, you will see Cretaceous cigar-shaped squid-like cephalopods called Belemnites, and the bivalve (clam) Buchia — gifts deposited by glaciers. Here are the most common.

Ammonites

Almost all of the ammonite specimens found near Harrison Lake are the toonie sized Cadoceras (Paracadoceras) tonniense with well-preserved outer whorls but flattened inner whorls. We find semi-squished elliptical specimens here, too. If you see a large, smooth, inflated grapefruit-sized ammonite, you are holding a rare prize — a Cadoceras comma ammonite, the macroconch or female of the species.  

Ammonites were predatory, squid-like creatures that lived inside coil-shaped shells. Like other cephalopods, ammonites had sharp, beak-like jaws inside a ring of squid-like tentacles that extended from their shells. They used these tentacles to snare prey — plankton, vegetation, fish and crustaceans — similar to the way a squid or octopus hunts today.

Within their shells, ammonites had a number of chambers called septa filled with gas or fluid, and they were interconnected through a wee air tube. By pushing air in or out, they were able to control their buoyancy. 

These small but mighty marine predators lived in the last chamber of their shell and continuously built new shell material as they grew. As they added each new chamber, they would move their squid-like body down to occupy the final outside chamber.

Interestingly, ammonites from Harrison Lake are quite similar to the ones found within the lower part of the Chinitna Formation near Cook Inlet, Alaska, and Jurassic Point, Kyuquot, on the west coast of Vancouver Island — some of the most beautiful places on Earth. 

Buchia (bivalve) Clams

The bivalve or clam Buchia are commonly found at Harrison Lake. You will see them cemented together en masse. . They populated Upper Jurassic–Lower Cretaceous waters like a team sport. When they thrived, they really thrived, building up large coquinas of material. Large boulders of Buchia cemented together en masse hitched a ride with the glaciers and were deposited around Harrison Lake. Some kept going and we find similar erratics or glacier-deposited boulders as far south as Washington state. 

Buchia is used as Index Fossils. Index fossils help us to figure out the age of the rock we are looking at because they are abundant, populate an area en masse, and then die out quickly. In other words, they make it easy to identify a geologic time span.

So what does this mean to you? Now, when you are out and about with friends and discover rocks with Buchia, or made entirely of Buchia, you can say, “Oh, this looks to be Upper Jurassic or Lower Cretaceous. Come take a look! We're likely the first to lay eyes on this little clam since dinosaurs roamed the Earth.” 

You will impress the pants off them — very high-five worthy.

Fossil Collecting at Harrison Lake Fossil Field Trip — Getting there

This Harrison Lake site is a great day trip from Vancouver or the Fraser Valley. You will need a vehicle with good tires for travel on gravel roads. Search out the route ahead of time and share your trip plan with someone you trust. If you can pre-load the Google Earth map of the area, you will thank yourself. 

Heading east on from Vancouver, it will take you 1.5-2 hours to reach Harrison Mills. 

Access Forestry Road #17 at the northeast end of the parking lot from the Sasquatch Inn at 46001 Lougheed Hwy, Harrison Mills. From there, it will take about an hour to get to the site. Look for signs for the Chehalis River Fish Hatchery to get you started. 

Drive 30 km up Forestry Road #1, and stop just past Hale Creek at 49.5° N, 121.9° W (paleo-coordinates 42.5° N, 63.4° W) on the west side of Harrison Lake. You will see Long Island to your right. 

The first of the yummy fossil exposures are just north of Hale Creek on the west side of the road. Keep in mind that this is an active logging road, so watch your kids and pets carefully. Everyone should be wearing something bright so they can be easily spotted.

How to Spot the Fossils

The fossils here are easily collected—look in the bedrock and in the loose material that gathers in the ditches. Specimens will show up as either dark grey, grey-brown or black. Look for the large, dark-grey boulders the size of smart cars packed with Buchia. 

And while you are at it, be on the lookout for anything that looks like bone. This site is also ripe for marine reptiles—think plesiosaur, mosasaur and elasmosaur. As a citizen scientist and budding palaeontologist, you might just find something new!

What to Know Before You Go

Fill your gas tank and pack a tasty lunch. As with all trips into British Columbia's wild places, dress for the weather. You will need hiking boots, rain gear, gloves, eye protection, and a good geologic hammer and rock (cold) chisel. 

Wear bright clothing and keep your head covered. Slides are common, and you may start a few if you hike the cliffs. If you are with a group, those collecting below may want to consider hardhats in case of rockfall — chunks of rock the size of your fist up to the size of a grapefruit. They pack a punch. 

Bring a colourful towel or something to put your keepers on. Once you set rock down, it can be hard to find again given the terrain. I take the extra precaution of spraying the ends of my hammers and chisels with yellow fluorescent paint, as I have lost too many in the field. You will also want to bring a camera for the blocks of Buchia that are too big to carry home. 

Identifying Your Treasures

When you have finished for the day, compare your treasures to see which ones you would like to keep. In British Columbia, you are a steward of the fossil, which means they belong to the province, but you can keep them safe. You are not allowed to sell or ship them outside British Columbia without a permit. 

Once you get home, wash and identify your finds. Harrison Lake does not have a large variety of fossil fauna, so this should not be difficult. If your find is coiled and round, it is an ammonite. If it is long and straight, it is a belemnite. And if it looks like a wee fat baby oyster, it is Buchia. This is not always true, but mostly true.

What about collecting fossils in all seasons?. Everyone has a preference. I prefer not to collect in the snow, but I have done it. While sunny days are lovely, it can also be easier to see the specimens when the rock is wet. So, do we do this in the rain? Heck, yeah! 

In torrential rain? 

Yes — once you are hooked, but for your casual friends or the kiddos, the answer is likely no. Choose your battles. They may come with you, but a cold day getting soaked is no fun. 

In time, you will find your inner fossil geek — probably with your first find. And that's just the tip of the iceberg. First, it will be you, then your kids, your friends and then your neighbour. Once you start, it is easy to get hooked. Fossil addiction is real, and the only cure is to get out there and do it some more. You've got this!

References and further information:

A. J. Arthur, P. L. Smith, J. W. H. Monger and H. W. Tipper. 1993. Mesozoic stratigraphy and Jurassic palaeontology west of Harrison Lake, southwestern British Columbia. Geological Survey of Canada Bulletin 441:1-62

R. W. Imlay. 1953. Callovian (Jurassic) ammonites from the United States and Alaska Part 2. The Alaska Peninsula and Cook Inlet regions. United States Geological Survey Professional Paper 249-B:41-108

An overview of the tectonic history of the southern Coast Mountains, British Columbia; Monger, J W H; in, Field trips to Harrison Lake and Vancouver Island, British Columbia; Haggart, J W (ed.); Smith, P L (ed.). Canadian Paleontology Conference, Field Trip Guidebook 16, 2011 p. 1-11 (ESS Cont.# 20110248).


Wednesday, October 20, 2021

HORNBY ISLAND FOSSIL COLLECTING

Pachydiscus suchiaensis ID: 18-08-CP-002
Hornby is a glorious place to collect. It is family and dog friendly. You need to dress for beach collecting preferably with rubber boots, eye protection and clothing for both sun and rain. 

I like to bring a 5-gallon bucket or hard plastic bottomed backpack for my finds. Whatever you bring is going to get wet, muddy and laced with sand. 

As well as a rock hammer, I bring a 2-4 pound sledgehammer and rock pick for collecting and cracking open the concretions here. If you are lucky, when you split them you see a fossil hidden within. 

While that is not always the case, the rewards are well-worth. One such beauty from a glorious day of collecting on Hornby is the beautiful ammonite you see here.

It is nestled amongst the seaweed and modern oysters clinging to the grey shales of the Northumberland Formation is the Upper Cretaceous (Campanian) ammonite Pachydiscus suchiaensis. This is one of my favourite species and is treasured both for its beauty and the fossil site it hails from. 

This darling was found in situ in the 72 million-year-old sediments at Collishaw Point on the northwest side of Hornby Island, southwestern British Columbia.

The island is beautiful in its own right and the fossils from here often keep some of their original shell or nacre which makes them quite fetching. This fellow is found amongst gastropods, shark teeth, fossil crabs, baculites and other bivalve fossils. 

Many of the fossils found at this locality are found in concretions rolled smooth by time and tide. The concretions you find on the beach are generally round or oval in shape and are made up of hard, compacted sedimentary rock. 

These past few years, many new and wonderful specimens have been unearthed — particularly by members of the Vancouver Island Palaeontological Society (VIPS). 

Two particular finds are jaw-droppers — a Diploceras (think one-metre long paperclip, except it is a heteromorph ammonite) longer than your arm and Actinosepia gladius — internal hard body part found in many cephalopods — of a Vampyropod, a member of the proposed group Vampyropoda — equivalent to the superorder Octopodiformes — which includes vampire squid and octopus. 

Not all of these beauties come out in one piece and as well as amazing collecting skill, the VIPS boasts some of the best Fossil Preparators in British Columbia. A nod of respect to both Jason Hawley and Rick Ross in this regard. Rick is a skilled collector and found a rather nice and rare pachydiscid ammonite at Hornby this past year that I had never seen before. It has been a good year for collecting at Collishaw Point. Another notable find was the decapod, Archaeopus vancouverensis (Woodward 1896), found by Adam Melzak this past summer. If you are looking to get out and about, fossil collecting on Hornby Island is the perfect day trip or weekend getaway.

Where to View the Fossils:

The Courtenay Museum, Qualicum Museum and Pacific Museum of the Earth have delightful collections of specimens from the Upper Cretaceous of Hornby Island. This lovely heteromorph ammonite, Nostoceras hornbyense (Whiteaves, 1895) is a classic. The photo below is courtesy of John Fam, Vice-Chair of the Vancouver Paleontological Society (VIPS) on a recent visit to poke through the collections at the Pacific Museum of the Earth. 

It is a classic example of the heteromorph specimens found at Hornby. Bob Copeman found the best Nostoceras hornbyense I have ever seen from these outcrops. Lucky for you, a replica of that specimen has been made is available to be purchased from the VIPS. Always a nice addition to the collection — especially if you keep a teaching collection where specimens need to be handled by younger, rougher hands.

Nostoceras hornbyense (Whiteaves, 1895)
The main topographic feature on Hornby Island is an arcuate mountain of the resistant cliff-forming Geoffrey formation. Near Shingle Spit about half a mile from the coast is Mt. Geoffrey 920-foot peak; from there the mountain gradually drops in elevation to the southeast and to the north.  

It is 700-feet of conglomerate in a homocline striking N 20° W and dipping to the northeast at a shallow angle of about 6°. 

The apex of the arcuate mountain belt points to the southwest. The coast of Hornby is probably a rising shoreline, as indicated by the almost perpendicular cliffs along its periphery. A hundred (100) foot cliffs of Lambert shale extends from Shingle Spit to Phipps Point, while from the latter to Boulder Point, the cliffs are not as steep and are covered in many places by vegetation.

Behind the mountain and almost enclosed by it is the fertile, green Strachan Valley. On the large peninsula which extends in a southeast direction from the north of the island towards St. John’s Point, the Hornby Formation outcrops form the cliffs on the east side of Tribune Bay. The highest of these is about 200 feet. The argillaceous Lambert and Spray formations form the subdued lowlands of the island.