Wednesday 18 February 2009

HAIDA GWAII : ISLANDS OF THE MIST

The islands have gone by many names. To the people who call the islands home, Haida Gwaii means “island of the people,” it is a shortened version of an earlier name, Haadala Gwaii-ai, or “taken out of concealment.” Back at the time of Nangkilslas, it was called Didakwaa Gwaii, or “shoreward country.” 

By any name, the islands are a place of beauty and spirit and enjoy a special place in both the natural and supernatural world.

Haida oral history traces the lineage of their families back to the ocean’s origins. Spear points from Huxley Island confirm a date of between 12,500 - 13,500 years ago. Their stories bear witness to the last the ice age, great floods, changes in sea levels and the arrival of the first tree – each binding them closer to the land and sea and enriching our understanding of this special place.

The islands form part of Wrangellia, an exotic terrane that includes parts of western British Columbia, Vancouver Island and Alaska. Today, the mist-shrouded archipelago of Haida Gwaii is separated from the British Columbia mainland by Hecate Strait, a 40-mile wide channel of tempestuous water.

Haida oral tradition tells of a time when the strait was mostly dry, dotted here and there with lakes. And indeed, 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.

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 an ice-sheet, a thick mass of flowing ice that ran tandem with the Cordilleran sheet in the Hecate Lowlands.

Looking around today, you can see where the glaciers left their mark. Many of the Islands’ valleys sport the tell-tale post-glaciation U-shape profile and picturesque erratic boulders can been seen sitting like sentinels on the beach, lone watchmen with an eye to the sea. While the glaciers on the Queen Charlottes were localized, to the east, what had once been and would again be the continental coast was pressed down beneath over a kilometer of ice — the Cordilleran ice sheet.

The melting of the glaciers, between 15,000 and 10,000 years ago, which coincides with the Siberian big-game hunters migrating inland on foot across the Bering Land Bridge, had two other significant effects on the level of sea and land. The first was the release of all the previously locked up water, causing a dramatic rise in sea levels. The second was the simultaneous rise of the continental edge and fall of the islands of Haida Gwaii.

This rise in sea levels transformed the westernmost highlands and mountains of ancient BC into the archipelago of Haida Gwaii and its inhabitants into the master seafarers of the West Coast.

The Hecate Strait served the Haida much as the English Channel served the British after the Norman Conquest: it was a formidable moat that discouraged attacks from the mother continent, but which they could cross at will to explore, trade, and pillage.

For many cultures, obtaining the stable food supply and permanent residences needed to develop advanced artisanship and specialized trades and crafts required becoming an agrarian society: clearing fields, planting crops, and/or raising livestock. But for the Haida, Mother Nature served as farmer, tending the tideland fields.

The enormous difference between high and low tide in Haida Gwaii – up to twenty-three vertical feet – means that twice a day, vast swathes of shellfish are unveiled, free for the taking. An ancient Haida saying is still often heard today, “When the tide is out, the table is set.” Archaeological evidence shows that by about five thousand years ago, gathering shellfish replaced hunting and fishing as their primary food source. The shellfish meat could be smoked, skewered on sticks, and stored for use in winter or for travel.

Over the centuries, the discarded shells accumulated in mounds many feet thick, called middens. The thickness of the middens and carbon dating the shells provide good timelines for human habitation. In addition, as described in the sidebar, chemicals leaching from the shells helped “embalm” bone and antler artefacts that would otherwise have decayed.

Freed from the need to chase game or till soil, the Haida, sometimes called the Vikings of the West Coast, developed their equivalent of the Norse Longship: the war canoe. Whereas any European wooden boat for more than a few people had to be pieced together from planks and ribs, the enormous red cedars of Haida Gwaii allowed carving one-piece dugout canoes up to seventy feet long.

Paddled by as many as thirty warriors – sails did not come into use until after contact with Europeans – these long, elegant craft ranged from Alaska to California, trading for or taking what they wanted. It’s interesting to note that equality in job opportunities is not such a recent notion. It was not unheard of for women to be part of Haida war parties, and they were apparently as much feared as their male shipmates. Naval battles on the ancient Northwest coast may not have rung with the echo of cannon or musket shots, but they would still have been fearsome and deadly. Rocks weighing up to fifty pounds, aptly named canoe breakers, were hurled at enemy boats in attempts to stave in their thin sidewalls. A rope running through a hole drilled in the canoe breaker allowed for its retrieval and reuse.

Presumably, rapidity in retrieval was called for to prevent the embarrassment of your enemy sinking you with your own rock. If canoe breakers were the analogue of cannon, the equivalent of the musket was the atlatl (pronouced"ott-lottle"). 

In any city park, you will see dog walkers using a long plastic device with a scoop to catapult balls for Rover’s retrieving pleasure. If you’ve used one of these, you’ve experienced how much faster and further you can hurl a ball with it than with your unaided arm. You might have thought of this as a cunning modern gadget, but in fact, it’s a variation on the ancient atlatl, or spear-thrower, in use for twenty-five thousand years. The spear or dart lay in a groove in the throwing stick as they were both held in one hand. As the user swung that hand overhead, he released the missile. The butt end of the spear lodged in a notch at the tip of the atlatl until it launched forward at fearsome speed.

In South America, the Spanish Conquistadors were unpleasantly surprised to find that atlatl darts could pierce their armoured breastplates. Indeed, it is the awesome effectiveness of such weapons that has led some scholars to suggest that the extinction in North America of many species of large animals – megafauna, in the scientific jargon – was caused by the encroachment of man.

Giant beavers, oversized ground sloths, and huge armadillo-like creatures all disappeared within a couple of thousand years — a mere heartbeat in geological terms. Other scholars hotly dispute that humans were solely responsible for these extinctions. Significantly however, the disagreement is based on arguments about what effects the changing environment had on these animals, about the timing of human arrival in America, the possible speed and methods of human immigration down the two continents, and whether and when viable ice-free corridors existed down the center of North America; no one appears to be arguing that ancient peoples were technologically incapable of killing such large beasts in enormous numbers.

We know that the islands housed grizzly bears some 13,600 years ago and while they no longer live in the region, we are still searching for clues as to their disappearance. We also find evidence in caves of deer bones dating back 12,600 years, suggesting a post-glacial arrival and a date well before the arrival of Europeans, who were originally credited with their arrival.

Why did some of the larger game on the lush islands thrive for a time and then vanish altogether? Rapid environmental and geographical changes combined with more efficient hunting methods form part of the answer.

We often think that exploiting a renewable food source to extinction, or at least to the point it can no longer feed us, is exclusively a problem of the modern age. Passenger pigeons across the continent, cod on the east coast, and the imperilled salmon on the west coast all come to mind. But the evidence suggests this may well have occurred many times in the past.

If, as the saying goes, “Those who forget the past are condemned to repeat it.” we would be wise to learn from the history of the early humans in North America. The Haida know the dangers of taking too much from any one place, leaving nothing for the next season. Logging has had a great impact on the salmon stock, particularly the Sockeye whose numbers have dwindled significantly.

The watershed that once protected the streams has been laid bare, allowing seasonal floods to run faster and higher, destroying spawning pools and clawing outside channels. Ain River, once bursting with salmon is now all but bare. A similar fate awaits the Copper River as most of the watershed surrounding it has been logged and the salmon feel the change – they are down to critically small numbers. They have a plan for the islands their lives and spirits are intertwined with. They know that their future and the fate of future generations run parallel with the health and lifeblood of the land beneath their feet and the oceans that crest their shores - Yah’guudang - respect for this place and for all living things.

They know that managing the wealth of logging with the health of their streams and river systems, especially the vital headwaters, is paramount to their future.

The arrival of cedar, called “Tsuuaay” by the Haida, had profound effects on the material culture of the Haida (Approx 4000 BC). Once they were able to build canoes to fish year-round (Halibut, Red Snapper, Ling Cod etc) and could access sea mammals, they no longer only depended on the salmon to return at certain times. The cedar bentwood box, a genius idea in food conservation and storage, allowed them to store food for the winter and reduced their dependence on hunting land mammals throughout the year wained.

The arrival of cedar marks a whole new stone tool tradition. The microblade is abandoned for larger ground tools, which are more appropriate for working with cedar.

Haida stories, songs, dances and crests are displayed through the ancient tradition of feasting and potlatching, where prestige is gained through the distribution of property. This generosity of spirit and sharing has carried on as they now share their lands with newcomers. Haida Gwaii, once the exclusive domain of the Haida people, is now home to many.

Homesteaders began to arrive in the…. Fishermen, others… Their stories have added another layer of richness to this moss-covered landscape.

Protective Shells: How Middens Preserve Bones:

Having food “packaging” accumulate in vast heaps around towns and villages is hardly a modern phenomenon. Many First Nations sites were inhabited continually for centuries. The discard shells and scraps of bone from their food formed enormous mounds called middens.

Left over time, these unwanted dinner scraps can transform through a quiet process of preservation. Time and pressure leach calcium carbonate from the seashells and help “embalm” bone and antler artifacts that would otherwise decay. Bone already contains calcium carbonate, as well as calcium phosphate, but it is also made of protein, cells and living tissue. Decaying bone acts as a sort of natural sponge that wicks in the calcium carbonate displaced from the shells. As protein decays inside the bone, it is replaced by the incoming calcium carbonate. This makes the bone harder and more durable, somewhat as plaster applied to the fabric of a cast makes the structure stiffer and more robust. In addition, the presence of shells can change corrosive acidic soil into more alkaline or neutral earth, which also helps to preserve the bone.


Rock n’ Roll: The Convoluted – And Disputed – Prehistory of Haida Gwaii


The Queen Charlotte Islands are at the western edge of the continental shelf and form part of Wrangellia, an exotic terrane of former island arcs, which also includes Vancouver Island, parts of western mainland British Columbia and southern Alaska. While we’ll see that there are two competing schools of thought on Wrangellia’s more recent history, both sides agree that many of the rocks, and the fossils they contain, were laid down somewhere near the equator. They had a long, arduous journey, first being pushed by advancing plates, then being uplifted, intruded, folded, and finally thrust up again. It’s reminiscent of how pastry is balled up, kneaded over and over, finally rolled out, then the process is repeated again.

This violent lifestory applies to most of the rock that makes up the Insular Belt, the outermost edge of the Cordillera. Once in their present location, the rocks that make up the mountains and valleys of this island group were glaciated and eroded to their present form. Despite this tumultuous past, the islands have arguably the best-preserved and most fossil-rich rocks in the Canadian Cordillera, dating from very recent to more than 200 million years old. On these details, there is a pretty broad consensus. On much else, including exactly where the Wrangellia terrane was born and how fast it moved to its present position, there is lively debate.

The two rival theories each rely on a different type of evidence: biogeographic or paleomagnetic. Volumes have been written on this complex argument. We’ll follow a single thread of the debate to get a sense of the science being marshalled on both sides. Biogeographic evidence compares the types of fossils found in rock with the historic ranges of the living creatures they were formed from, and sometimes with the ranges of comparable contemporary life forms.

Paleomagnetic dating uses the history of the Earth’s magnetic fields. It can give a rough estimate of how far north or south of the equator rock was formed. Palomagnetic data from Triassic rock of Wrangellia suggest that it was laid down somewhere in a band about two thousand miles wide, centered on the equator. The biogeographic work of geologist Dr. Tim Tozer on the fossil faunas of Haida Gwaii concurs with this. The fossils found in the Triassic rock of Wrangellia are equatorial or low latitude life forms quite different from those found today on the Continent at the latitude of the island.

This suggests those rocks were in the equatorial region during the Late Triassic, just over 200 million years ago. Further supporting this, Dr. Jim Haggart, a geologist at the Geologic Survey of Canada, who has worked extensively with the fossils of Haida Gwaii, notes that Lower Jurassic ammonite faunas found on Haida Gwaii are very similar to those found in the Eastern Pacific around South America and in the Mediterranean. The presence of these ammonites seems to indicate that the rock was still at or very near the equator during the Lower Jurassic epoch, which ended roughly 175 million years ago.

To this point in prehistory, the paleomagnetic and biogeographic evidence is in reasonable harmony (at least about how far south Wrangellia was created. There’s much debate about just where along the equator is was, but we’ll ignore that for simplicity’s sake.).It is as we move up through the rock column to younger layers that the two lines of evidence start to conflict. Around the beginning of the Middle Jurassic, the fossils found on the Queen Charlotte Islands, Vancouver Island and in southern Alaska start to be dominated by forms found in high latitudes. This suggests that by the time of the Middle Jurassic, about 165 million years ago, Wrangellia had already completed much of its journey northward. Similar biogeographic evidence from Cretaceous rocks supports this idea as the Cretaceous ammonite, bivalve and radiolarian faunas all appear to be high latitude as well.

In contrast, the paleomagnetic data from Wrangellian Cretaceous rocks on Vancouver, Hornby and Texada Islands initially suggested that they were formed while Wrangellia was still at low latitudes, roughly around present-day southern Baja Mexico. More recently, however, paleomagnetists have conceded that Wrangellia may have gotten as far north as central California by the Early Cretaceous. 

The paleomagnetists now maintain that the islands of Haida Gwaii arrived at their present-day position by the Lake Cretaceous or even earlier, around 60 million years ago. This revised dating still means these two groups do not see eye to eye on just when the islands arrived at their current position. However, the paleomagnetists face some major stumbling blocks:

They can’t locate many of the fault lines necessary to buttress their case. For example, rocks on either side of the valley at Churn Creek north of Lytton originated 2000 miles apart according to paleomagnetic calculations, but no fault line has yet been found running between the supposedly separately created sides.

The paleomagnetists assert that it’s just a matter of time before the required faults are unearthed — mere formalities they are happy to leave to the geologists. Needless to say, many geologists are unimpressed with having these burdens thrust upon them by “paleomagicians” unable to back-up their case. Both sides are able to find many faults in the opposing theory, if not in the Wrangellian terrane.So, are scientists discouraged by such vast gaps in their knowledge of the early Earth? On the contrary, they’re excited.

Paleogeology would be a very dull field if all that was left to do was to cross a few trivial Ts and dot a few insignificant Is. As it is, there are vast opportunities to have your name go down in history by making major contributions to our knowledge of Earth’s prehistory.

Paleomagnetic Dating

You probably remember a demo from science class where a sheet of paper is laid over a bar magnet, and iron filings are scattered lightly onto it. The filings line up with the fields generated by the magnet, in patterns that look rather like bottom-to-bottom fireworks bursts. Something similar occurs when rock is formed, whether by heat or by sedimentation:

Microscopic iron particles in the rock line up with the Earth’s magnetic fields as they are oriented at that time. But unlike the iron filings on the paper, which shift if the paper or the magnet is moved, iron particles in solidified rock remain frozen in their alignment unless the rock is reheated to 600°C or more.

This means that even when the Earth’s magnetic poles flip end for end – something they have done several hundred times during Earth’s history – the iron stays aligned as it was when the rock was formed. By comparing the residual magnetism in the rock with the known historical changes in the Earth’s magnetic fields, an age and birthplace for the rock can be easily be estimated — in theory.

The principle behind paleomanetic dating is easy to summerize: the practise is much more complicated. The intervals between pole reversals fluctuate wildly, from as little as one hundred thousand years to tens of millions of years. The time taken for the shifts to complete once started also varies, from a thousand to eight thousand years. Imagine trying to time events with a grandfather clock that had a pendulum which swung at intervals that could vary from one minute to many hours, while the period of the pendulum swing itself ranged randomly from one second to eight seconds, and you’ll get a sense of the complexity of paleomagnetic dating. While far from a perfect science, paleomagnetic dating provides valuable pieces of the puzzle of Earth’s past.

The Triassic/Jurassic Extinction: A Killer From Outer Space Or Inner Earth?

Located as they are in Canada’s most active earthquake zone, the islands of Haida Gwaii have had their share of shake-ups and scourings. Many of the Islands’ hillsides are scarred by slides (any specific examples?). But the rock beneath speaks of an even more violent past. Very few people know that the rocks here hold 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.

Queen Charlotte Radiolarians: Time Keepers of the World Wide Mesozoic:

Radiolarian microfossils – tiny, siliceous, single-celled organisms – tell the tale. These wee timekeepers have been living in the world’s oceans for about 600 million years. Because they occur in continuous and well-dated sequences of rock in the Queen Charlottes, these exquisitely beautiful microfossils act like a yardstick, helping geologists accurately date rock from around the globe.

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 younger Jurassic rock shows a rebound of radiolarian diversity (though of course, in different forms) - a diversity that continues to flourish and expand in today’s oceans. Inset: The islands of Haida Gwaii are most noted for their fossil ammonites, the coiled cousins to modern day nautilus. These perfectly preserved specimens tell of a deep water environment and warm tropical seas.

Dr. Mclearn, a geologist who has worked on the geology of Haida Gwaii published on the strata exposed at Maple Island was stratigraphically higher than the majority of Albian localities in Skidegate inlet. His findings show that the macrofossil fauna belonged to the Upper part of the Sandstone Member of the Haida formation.

The western end of the island contains numerous well-preserved inoceramids (Birostrina concentrica) and a few rare ammonites (Desmoceras bearskinese). The eastern shores house unusual ammonite fauna in the finer grained sandstones.

Most were in extremely hard concretions while others were loose in the shale. Species include Anagaudryceras sacya and Tetragonites subtimotheanus. A large whorl section of the rare Ammonoceratites crenucostatus was found in 2003.

Sidebar: Hoploparia sp. Paper with Torrey Nyborg (Loma Linda University) on the Rogueus sp. (Raninid crab) from Northwest Bay.

Photos: The ammonites, Desmoceras; Brewericeras; Douvelliceras, from Lower Cretaceous, Middle Albian, Haida Formation deposits

Sidebar: Evidence of human activity dating from 12,500 - 13,500 years ago. Section Cove finds including spear points, salmon remains and bear bones preserved in limestone.

Sidebar: Earliest presence of grizzly bears, 13,600 years ago, work of Rebecca Wigen

Photo: Shell coquina, with abundant Spisula praecursor clams, Late Miocene (~ 10 million years old, Skonun Formation)