Comox Valley Naturalists Society
Knowing Nature . . .
July 22, 2005
The Buttle Lake corridor in Strathcona Provincial Park provides access to some of the most spectacular wilderness hiking in BC. On the far side of Buttle Lake Marble Rock Canyon is visible as an impressive band of white rock high above the lake. It provides a tantalizing glimpse of part of the massive limestone formation known as Marble Meadows. There are no roads to get there, so like most hikes in the Buttle Lake area, it is a long, uphill climb.
At the top of the ridge, the hiker is rewarded with the sight of bottle-green lakes with clear, deep water. The lakes are nestled into a landscape that looks barren at first, with bald outcrops and scattered bony chunks of rock. From the lakes flow streams lined with lush green vegetation and wildflowers; anemones, yellow buttercups, purple violets, white marsh marigolds and saxifrage.
Between lakes there are several suitable camping spots (no facilities), and good views all around. From the camping area, the trail continues and is marked with cairns. It leads to the Wheaton hut, a small shelter built in 1970 by students from Shawnigan Lake, commemorating a schoolfellow who died in a hiking accident in Europe.
Beyond Wheaton hut the landscape becomes more fascinating, and the trail less evident. The hike traverses massive beds of limestone. Limestone is actually a “life stone”, packed with organisms that lived millions of years ago. The sandwich-like layering of masses of these organisms eventually turned to fossilized stone and became limestone. This bedding down of layers makes limestone a sedimentary rock. When limestone undergoes changes through heat and pressure it becomes a metamorphic rock called marble.
The limestone in Strathcona, known as the Buttle Lake Formation, dates from the early Permian period and is around 280 million years old. Even more mysterious is the fact that these fossilized creatures originated from the bottom of an ancient, tropical sea near present day Mexico. This shallow sea surrounded an island paradise called Wrangellia. Over millions of years, Wrangellia drifted north, until it collided with the continental mainland, and became the backbone of Vancouver Island. Volcanic actions of uplifting, tilting, folding and faulting brought the fossilized sea beds to the mountaintops.
Most of the visible fossils from the ancient seabed are crinoids, or “water lilies”. In life, crinoids were attached to the sea floor, with a long, flexible cord-like section and a feathery top for catching food. Fossilized crinoids are visible in cross-section and most are the size of a dime or less. In long-section they are tube shaped and ringed with grooves. The largest intact fossilized crinoid found in Marble Meadows was over a metre in length. Fossilized shells can also be found, but these aren’t like our present day clams and cockles. They are brachiopods, creatures that were attached to the seafloor by spiny stalks. Fossils, though fascinating, are just one aspect of the curious mysteries of limestone.
Limestone makes up a landscape called “karst”. Over thousands of years, limestone is weathered and eroded by rain. Rainwater picks up carbon dioxide as it falls and runs through the soil. The carbon dioxide in rain water, forms a weak solution of carbonic acid and erodes the limestone through cracks and fissures. Walking over limestone can be like walking on a glacier, with crevasse-like clefts in the rock. All of the The weathering action of water can also create underground limestone caves. These caves affect water drainage, and streams can magically disappear and reappear in the landscape. Sometimes the caves cause a slumping, or collapse of the ground surface, and such features are called sinkholes. The special effects of the karst landscape are very apparent in Marble Meadows.
Karst ecosystems and their complex cave and water systems are fragile, and very sensitive to disturbance such as mining and logging. Karst landscapes foster many rare plant species, which only exist in limestone habitats. Caves provide shelter for many animals, including bats. The limestone fossil beds provide a fascinating glimpse into the ancient and exotic history of Vancouver Island.
To get to Marble Meadows, one must canoe across Buttle Lake from Auger Point to Phillips Creek. If possible the crossing should be made in the morning as winds and waves tend to pick up in the afternoon. Phillips Creek is the start of a well marked trail which switchbacks up through pristine forest to Marble Meadows. The climb is a steady 5-6 hour hike, and most people backpack in for a few nights or more.
The Marble Meadows region is rugged and recommended for experienced hikers. The trail isn’t always clear beyond the Limestone Lake campsite so it is best to travel with a GPS, compass, topographical map, or an experienced leader. Fossils should not be removed from the park.
Fossils and karst formations, such as disappearing and reappearing streams, can also be seen at the Karst Creek loop trail, easily accessible on the road along Buttle Lake. The Buttle Lake corridor in Strathcona Park is situated an hour’s drive west of Campbell River on Highway 28. Fine examples of fossils from Marble Meadows can also be viewed at the Courtenay & District Museum.
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