Download Read extract - Diane Mitchell

IN LOVE WITH EARTH
in SQUAMISH & WHISTLER
A guide to the landscapes and nature around two
towns lucky enough to be situated in one of the
most beautiful corners of the world
Diane Mitchell
INTRODUCTION
Known as one of the most scenic drives in the world, the Sea to Sky Highway has plenty to offer locals
and tourists alike. All along the route there are incredible views – rocky peaks, glaciers, plunging rock
faces and waterfalls, with the odd dormant volcano and ice sheet thrown in for good measure. From
the time you round the corner at Horseshoe Bay and begin driving along Howe Sound, to Pemberton
and beyond, the landscape lover will never be bored. For the nature lover, there is equally much to
appreciate. From sea level to the high alpine, there are animals, plants and fungi to be spotted – some
rare and some seen throughout the area. A trip onto one of the many trails can lead to moments of
quiet contemplation, or moments of adventure when one of the larger animals – a deer, coyote or bear
perhaps – goes by.
The towns of Squamish and Whistler sit amid these wonders. The area around Squamish in particular
shows us much about the history of the Earth that led to the formation of the landscape, as well as how
it keeps on changing, albeit slowly. As for nature, we are spoiled for choice, from the microscopic to the
ecosystem as a whole. In other words, there is much to explore, by car or by foot.
This book tells the story of the landscape and of the ecosystem that thrives here – and where to see
some of it. The goal of the book is to bring about a greater appreciation of how this staggeringly
beautiful corner of the world came to be, by interpreting some of the fascinating science behind it. The
book will have achieved its goal if it makes you as the reader see this area in a new light, or can recall
some of that story the next time you enjoy soaking up the Sea to Sky.
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EARTH HISTORY
Lying on the Pacific Ring of Fire, this area has a volcanic history that spans the last 170 million years.
The mountains are largely remnants of ocean floor and volcanic islands, deformed and pushed above
sea level by the collision of North America and the Pacific. In the last two and a half million years, an
ice age brought vast glaciers, interspersed with the eruption of newer volcanoes. These later events
have shaped the land into the mountains and valleys that we know and love today.
PACIFIC RING OF FIRE
To understand the landscape around Squamish and Whistler, first let us step back 300 million years. A
long chain of volcanoes – similar to the island arc that forms Japan today – languishes off the western
edge of the North American tectonic plate. The volcanic chain marks the boundary between the
continental plate and the vast ancestral Pacific oceanic plate. The plates are colliding. The ocean floor
moves eastwards, sinking beneath the westward moving continent. As it sinks, it causes the melting of
rock that rises to the surface forming the volcanic chain.
Trouble is brewing however. At 200 million years, the North American plate is moving fast enough to
collide with the volcanic chain. Over the next 100 million years the slow motion collision causes new
land to be pushed above sea level. To complicate matters, slivers of tectonic plates also slide in from the
north, adding to the geological carnage. All this begins the formation of what is to become much of
British Columbia.
Throughout this slow motion collision, the ocean floor carries on sinking beneath North America,
causing more volcanic activity. Around 175 to 100 million years, it is forming what will become one of
the largest rock structures in the world. Known as a batholith, this is a series of bodies of granite (and
granite-like rocks) that join together to stretch 1800 kilometres from Washington to Alaska. It is the
most important story in the formation of our Coastal Mountains – and is known as the Coast Mountain
Complex. These granitic rocks were once molten rock deep below the surface, where they cool before
they have the chance to erupt from a volcano. This rock that was once below the surface ultimately
becomes our current mountain ranges through the ongoing collision pushing them up.
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As we know, the story does not end there. The collision is ongoing
today. The continental and oceanic plates collide at a rate of about
four centimetres a year – roughly the rate your fingernails grow. This
is largely what is responsible for the earthquakes that shake western
North America as well as the volcanoes that dot the length of the
continent.
The process of one tectonic plate
sinking beneath another is called
subduction. This happens in many
places around Earth, including
around the rim of the Pacific plate.
The volcanism it causes has led to
the name Pacific Ring of Fire.
Complicating things is the relatively small Juan de Fuca oceanic plate
which sits between the North American and Pacific plates (west of
British Columbia, Washington and Oregon). This small plate collides with, and sinks beneath, North
America. The plate boundary lies offshore. When earthquakes hit this region they are generally caused by
this collision.
It is thought that the plate collision is causing our mountain ranges to be uplifted by two to four
millimetres a year. Glaciation and weathering are helping to redress the balance by slowly eroding the
mountains. This battle may be imperceptible to us, but over millions of years, the difference it makes is
staggering. To put it another way, the land that we stand on today was once rock buried several kilometres
below ground. All the rock above it has been eroded as the rock from below was pushed upwards.
Millimetre by millimetre, kilometre by kilometre, our mountains are shaped by this force that we are rarely
conscious of, but that is always present.
Blackcomb Mountain,
part of the Coast
Mountain Complex
– a body of granite
and granite-like rocks
(diorite, quartz diorite
and granodiorite) that
stretch from Washington
to Alaska.
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