||July/August 2007 issue||
A massive geological scar slicing diagonally across the Yukon, the Tintina Trench is
a rich and largely untouched wildlife corridor of staggering abundance
Photography by Patrice Halley with text by Andrew Findlay
Only if you were suspended in space could you fully
appreciate the geological scale of the Tintina Trench. It is painted on
the Yukon map like a crude brush stroke on a tattered canvas, running
nearly 1,000 kilometres from the Liard Plateau at the British
Columbia border to Alaska's Woodchopper Creek. Yet here on Earth,
northwestward through the trench toward the Yukon River, it is difficult
to fathom the fault line deep below that marks the edge of an
ancient North American continent.
A photo gallery tour of the Yukon's Tintina Trench, which slices diagonally across the territory from Alaska to British Columbia, tracing one of the world's major fault zones.
On a gusty summer afternoon, photographer Patrice Halley and
I wander up to the cloud-covered alpine tundra below Mount Mye,
in the Anvil Range. Cold mist rolls across the landscape as we perch
on the edge of a geological marvel that forms a wildlife corridor of
staggering abundance and also bears the imprint of human migration
and settlement dating back thousands of years. Thickets of willow,
the leaves already displaying rusty hues of autumn, become
fleeting images in the restless air. Under our feet is a thick carpet of
moss and lichen. Delicate coral-like shoots of sieve cup lichen and
grey reindeer lichen cushion our steps. Pausing atop a granite boulder,
we scan for a glimpse of Fannin's sheep, one of Tintina's wildlife
curiosities. I press my boot against the rock and ponder the history
concealed in the silent ground.
Between 120 million and 190 million years ago, the convergence of
tectonic plates forced land masses of igneous origin from the west to
attach to the much older rocks of North America - some 300 million
to 1.8 billion years old - as the continent merged with offshore volcanic
islands. In the same period, the land now occupied by Whitehorse
was submerged beneath a deep marine basin which gradually filled up
with sediments. About 100 million years ago, dinosaurs roamed the
freshly formed uplands in what is now the Yukon. About 60 million years
ago, after the sea drained away, plates on the south side of the trench
began a torturous 450-kilometre journey to the northwest. By the time this massive shift was over, rocks once located in northeastern
British Columbia had come to rest where the Pelly Mountains stand
today, across the trench from the Anvil Range.
|Click map to enlarge
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Can Geo POLL
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