Saturday 30 January 2010

STEPPING-STONE ISLANDS

Steeped in mist and mythology, the islands of Haida Gwaii abound in local lore that surrounds their beginnings. 

Today the Hecate Strait is a tempestuous 40-mile wide channel that separates the mist-shrouded archipelago of Haida Gwaii from the BC mainland. Haida oral tradition tells of a time when the strait was mostly dry, dotted here and there with lakes. 

During the last ice age, glaciers locked up so much water that the sea level was hundreds of feet lower than it is today. Soil samples from the sea floor of Hecate Strait contain wood, pollen, and other terrestrial plant materials that tell of a tundra-like environment. Whether or not the strait was ever completely dry during these times, it seems that it did at least contain a series of stepping-stone islands and bridges that remained free of ice. An ancient Haida tale, recorded in the late 1800s by a Hudson’s Bay Company trader, records the island's glacial history. 

Scannah-gan-nuncus, a boy who lived in the village now called Skidegate, had canoed up the Hunnah, a tributary to Skidegate Channel. Today, the Hunnah is a rocky creek, seldom deep enough to navigate. 

The Haida the legend accurately records that it used to be several times deeper. Tired from paddling upstream, Scannah-gan-nuncus landed to take a nap. “In those days at the place where he went ashore were large boulders in the bed of the stream, while on both sides of the river were many trees. While resting by the river, he heard a dreadful noise upstream. 

Looking to see what it was, he was surprised to behold all the stones in the river coming toward him. … all the trees were cracking and groaning … he went to see what was crushing the stones and breaking the trees. On reaching them, he found that a large body of ice was coming down, pushing everything before it.” Scannah-gan-nuncus’ experience with the glacier would have been familiar to the inhabitants of the islands. 

Today, the highest peaks are often bare of vegetation and snow-covered during most of the year, but back in the time of the glaciers, these same local mountains were the birthplace of advancing ice. 

Precipitation and a significant drop in temperature gave rise to the Queen Charlottes ice-sheet, a thick mass of flowing ice that ran tandem with the Cordilleran sheet in the Hecate Lowlands. Strolling around today, you can see where the glaciers left their mark on the Islands’ U-shape valleys, once a steep V-shape, now scoured into a smooth by glaciers that also deposited the erratic boulders can been seen sitting like out of place sentinels on the beach.

Thursday 28 January 2010

SALMON CHIEF: FOOD OF THE GODS

Salmon have permeated First Nations mythology and have been prized as an important food source for thousands of years.

For the Salish people of the Interior, salmon was the most important of the local fishing stock and salmon fishing season was a significant social event which warranted the nomination of a “Salmon Chief” who directed the construction of the hooks, weirs and traps and the distribution of the catch.

In the Interior of the province, archaeological evidence dates the use of salmon as a food source back 3,500 years. Sheri Burton and Catherine Carlson were able to isolate and amplify mitochondrial DNA from salmon remains from archaeological sites near Kamloops, and identified the species as Oncorhynchus nerka, or Sockeye salmon. No older salmon remains had been found in the Kamloops area until the 1970’s, when fossil salmon concretions were collected on the south shore of Kamloops Lake.

These concretions were originally dated as Miocene (24 – 5.5 million years old) by the Geological Survey of Canada, based on analysis of pollen grains found in the concretions. However, many local experts, including UBC geology professor W.R. Danner and the late geologists W.H. Mathews and Richard Hughes, suspected the remains were from the much more recent, Late Pleistocene epoch. But it was not until the early 1990s that Catherine Carlson and Ken Klein found definitive proof of this.

By good luck, the fish remains in the Kamloops Lake concretions had not been completely replaced by minerals – enough of the original organic bone collagen remained for radiocarbon dating. The corrected date is approximately 18,000 years. It is likely that erosion during the time of deposition had carried pollen down from Miocene layers in surrounding hills, to be deposited around the dead fish, causing the initial over-estimation of the age of the concretions.

An age of 18,000 plus years – sets the fossils firmly as the only salmonids of the Late Pleistocene in North America, a very significant find. The date also changed our ideas about the early climate of the Interior; the Thompson Valley could not have been covered by glacial ice for as long as originally thought.

It has long been accepted that the most recent series of ice ages began approximately 1.6 million years ago, beginning as ice accumulations at higher altitudes with the gradual cooling of the climate. Four times the ice advanced and receded, most recently melting away somewhere around 10,000 years ago. Ice retreated from southwestern British Columbia and the Puget Sound area around 15,000 years ago.

In the southern Interior, ice built up first in the northern Selkirk Mountains, then slowly flowed down into the valleys. Once the valleys were filled, the depth of the ice increased until it began to climb to the highlands and finally covered most of the Interior of British Columbia. Between ice advances, there were times when the Kamloops area was ice free and the climate warm and hospitable.

Glacial ice was believed to have initiated its most recent retreat from the South Thompson area around 11,000 to 12,000 years ago, but salmon remains from 18,000 years ago suggest that it may have actually began its northwest decline much earlier and indicating a much warmer climate in the Interior than archaeologists or geologists had originally estimated.

Eighteen thousand year-old salmon also challenge the archaeological notion that aboriginal people of the Interior have had access to salmon as a significant protein source for only a few thousand years. In the popular view, people living in the Okanagan and Thompson Valleys were felt to have moved to settlements that were semi-permanent about 4500 years ago.

By that time they would have had a seasonally regulated diet composed primarily of salmon and supplemented by local game - deer, elk, small mammals – and available shellfish, birds and plant foods. If salmon were present much earlier, it is possible that this pattern of food utilization may have arisen earlier than thought.

Richard Hughes had originally identified the fossilized Kamloops salmon as Oncorhynchus nerka or Sockeye salmon, the same species found in the 3,500 year old archaeological sites. But, using the carbon-13 isotope ratio, Klein and Carlson were able to determine that these salmon did not feed on protein from a marine source and relied solely on a freshwater diet.

In other words, they could not have spent part of their life in the ocean, as modern Sockeye salmon do. Based on the specimens’ smaller heads and stunted bodies, the longest measuring in at a pint-sized 11.5 cm, Klein and Carlson feel that the fossils are likely Kokanee, a modern landlocked variety of Sockeye.

Here two people very precious to me celebrate life's many gifts from land and sea at the 1994 Hunt Memorial Potlatch.

HALE CREEK FOSSIL FIELD TRIP

Tuesday 26 January 2010

Sunday 24 January 2010

Saturday 23 January 2010

Wednesday 20 January 2010

CHUCKANUT FOSSIL TRACKWAYS

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 including tracks of Diatryma, a massive flightless bird that reached up to 9 feet in height and made a living in the grasslands and swamps of the Eocene.

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.

WANNERIA DUNNAE

Wanneria dunnaeis an impressive trilobite from British Columbia's Eager Formation, and one of the more striking specimens found at the original research site of the lovely Lisa Bohach, a paleontologist now working out of Alberta.

The site has changed over the years, both physically and politically, but the one constant is the exquisite detail of the specimens. Both Wanneria dunnae and Ollenelus ricei are commonly found here. I had a eureka moment there a few years ago when ambling up the path to the main pit. The sun hit a wily would-be hiking track on a bit of shale at just the right angle. Closer inspection showed it to be a Tuzoia, one of the rare arthropods to come from the area.

Tuesday 19 January 2010

Tuesday 12 January 2010

MOONLIT PADDLE

CROCODILIAN UPSTARTS: THE CRUROTARSANS

Dinosaurs, long hailed as the rulers of the Triassic almost lost the title belt to a group of crocodilian upstarts, the crurotarsans. In a short lived battle for survival, geologically speaking, the two groups ran head-to-head for about thirty million years with the Crurotarsi butting their massive skulls and narrow snouts against their evolutionary opponent and ultimate successors, the dinosaurs.

The Crurotarsi or "cross-ankles" as they are affectionately known, are a group of archosaurs - formerly known as Pseudosuchians when paleontologist Paul Serono, the darling of National Geographic, renamed them for their node-based clade in 1991.

LIMESTONE AND SALT AIR: GORDES

Thursday 7 January 2010

CETACEA: HUMPBACK WHALE

Look at this lovely maternal bond between an adult Humpback whale female, Megaptera novaeangliae, and her young. Humpbacks are a species of baleen whale for whom I hold a special place in my heart. 

Baleens are whales who feed on plankton and other wee oceanic tasties that they consume through their baleens, a specialised filter of keratin that frames their mouths.

There are fifteen species of baleen whales. They inhabit all major oceans, in a wide band running from the Antarctic ice edge to 81°N latitude.

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, whales are known as g̱wa̱'ya̱m. Both the California grey and the Humpback whale live on the coast. Only a small number of individuals in First Nation society had the right to harpoon a whale. It was generally only the Chief who was bestowed this great honour. Humpback whales like to feed close to shore and enter the local inlets. Around Vancouver Island and along the coast of British Columbia, this made them a welcome food source as the long days of winter passed into Spring.

Humpback whales are rorquals, members of the Balaenopteridae family that includes the blue, fin, Bryde's, sei and minke whales. The rorquals are believed to have diverged from the other families of the suborder Mysticeti during the middle Miocene. 

While cetaceans were historically thought to have descended from mesonychids— which would place them outside the order Artiodactyla— molecular evidence supports them as a clade of even-toed ungulates — our dear Artiodactyla. Baleen whales split from toothed whales, the Odontoceti, around 34 million years ago.

Tuesday 5 January 2010

Saturday 2 January 2010

Friday 1 January 2010

Thursday 31 December 2009

ALPINE ADVENTURE FOSSIL FIELD TRIP

Camping at about 7,500 ft, we were treated to all four seasons and some great collecting.

Over the course of the week we collected some beautiful ammonites, several of which are new species, and saw a buck with a sexy set of horns, flocks of Franciscans and a majestic lone wolf.

The area is home to active research by UBC paleontologist, Louise Longridge, and boasts abundant fossil marine specimens and a chance to see the Triassic-Jurassic boundary, a rare treat.

Wednesday 16 December 2009

HAIDA GWAII: ISLANDS OF FIRE

Located as they are in Canada’s most active earthquake zone, the Queen Charlotte Islands have had their share of shake-ups and scourings. Many of the Islands’ hillsides are scarred by slides. But the rock beneath speaks of an even more violent past.

Very few people know that the rock in the Queen Charlottes holds the key to a catastrophic event from eons ago. We’ve heard tales and seen images of the cataclysmic damage caused by meteriorites smashing into the Earth’s surface.

Until recently, it was a meteorite impact that was blamed for the worldwide Triassic/Jurassic Mass Extinction. This wholesale dying out of species occurred some 200 million years ago. New evidence challenges the meteorite theory. Experts now believe that tectonic forces may have caused hundreds of volcanoes around the world to erupt simultaneously. The subsequent showers of volcanic ash would have altered the composition of the atmosphere dramatically and plunged the world into near total darkness for years until it settled from the sky.

The picture painted of the sun flickering fitfully through inky clouds, paling against the torrents of glowing lava, while everywhere life is smothered, poisoned, or starved, rivals the most apocalyptic imaginings of Hollywood or religion. We know from worldwide evidence that the extinction was dramatic and affected upwards of 70% of the world’s biota.

Perhaps counterintuitively, for one might think of water as a refuge from fire, smoke, and lava, it was marine lifeforms that suffered the most. This is particularly well documented in the rocks of the Queen Charlottes, especially at Kennecott Point and Kunga Island.

Radiolarian microfossils, tiny, siliceous, single-celled microrganisms, tell the tale. In the Upper Triassic rocks, which predate the extinction by about 10 million years, radiolarians are preserved in hundreds of forms. Just above them, in the early Jurassic rock layers laid down about the time of the great die-offs, only a fraction of the previous number of forms are represented. The more recent Jurassic rock shows a rebound of radiolarian diversity, though of course, in different forms, a diversity which continues to flourish and expand in today’s oceans.

Monday 16 November 2009

Sunday 15 November 2009

Wednesday 11 November 2009

Sunday 1 November 2009

Tuesday 27 October 2009

Thursday 15 October 2009

LUSH BOUNTY

The Bowron Lake Circuit is home to a variety of plant life. Large sections of the forest floor are carpeted in the green and white of dogwood, a prolific ground cover we are lucky enough to see in full bloom. Moss, mushrooms and small wild flowers grown on every available surface.

Thursday 8 October 2009

Wednesday 7 October 2009

Saturday 3 October 2009

Friday 2 October 2009

Thursday 1 October 2009

Monday 28 September 2009

Friday 25 September 2009

RADIALARIANS: TIMEKEEPERS OF ANCIENT SEAS

Radiolarian microfossils, tiny, siliceous, single-celled organisms, make for excellent timekeepers. Think of them as the world's smallest clocks. These wee fellows have been living in the world’s oceans for about 600 million years. Because they occur in continuous and well-dated sequences of rock, they act like a yardstick, helping geologists accurately date rock from around the globe.

Wednesday 23 September 2009

Monday 21 September 2009

MEGAFAUNA: EXTINCT GIANTS

Megafauna were part of a cohort of "giant" animals, species of large animals, reptiles, birds and mammals that went extinct during the Pleistocene as our rellies, the homeo sapien sapiens, were spreading out of Africa and southern Asia to populate the globe. Our rise marked the demise of many of the Earth's most interesting beasts. The term, 'megafauna' refers only to those species larger than forty-five kilograms. Many smaller animals who lived along side these giants also disappeared during the Pleistocene, but it is the largest of the lot who get the title and our attention.

While the fossil record shows that most of the megafauna from North and South America, northern Eurasia and Australia went extinct during this time, it is not the case for all large beasts. Blue Whales, hippopotamus and elephants are notable exceptions, surviving into modern times.

Were we to blame? The court is still out, but most scientists agree that we played a small role at least. Larger scale hunting, climate change, and spreading disease have all been fingered as the culprit for the loss, but, like most ancient mysteries, evidence is mixed and the truth is complicated. My vote is that their ultimate demise is a combination of the three.