Tuesday 30 December 2014

HAIDA GWAII: ISLANDS OF MIST

Steeped in mist and mythology, the islands of the Queen Charlottes 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 contain wood, pollen, and other terrestrial plant materials that tell of a tundra-like environment.

The court is still out on whether or not the strait was ever completely dry during these times, but it certainly contained 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 once roaring tributary to Skidegate Channel that is now 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 Queen Charlottes. In recent years, 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 you can see where the glaciers left their mark on the Islands’ U-shape valleys, once a steep V-shape, now scoured smooth by glaciers that also deposited the erratic boulders can been seen sitting like sentinels on the beach.

CRETACEOUS NANAIMO GROUP

The strata near Nanaimo and much of eastern Vancouver Island is underlain by sedimentary rocks of the Cretaceous Nanaimo Group. These mudstones, sandstones and conglomerates were deposited in deltas, rivers and marine environments between 95 and 65 million years ago. While there is a mix, almost all of the great fossil exposures are marine.

Monday 29 December 2014

CAMBRIAN TRILOBITES


The Cambrian was a time of expansion for the Earth's complex animal forms. Molluscs and arthropods and their friends with hard shells and exoskeletons dominated the seas. The specimen you see here is of a Wanneria dunnae trilobite from the Eager Formation, Rifle Range site near Cranbrook, British Columbia.

Thursday 25 December 2014

Friday 19 December 2014

JELLYFISH: DANCERS OF THE DEEP

This lovely ocean dancer with her long delicate tentacles or lappets and thicker rouched oral arms is a jellyfish. 

Her brethren are playing in the waters of the deep all over the world, from surface waters to our deepest seas — and they are old. They are some of the oldest animals in the fossil record.

Jellyfish and sea jellies are the informal common names given to the medusa-phase or adult phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria — more closely related to anemones and corals.

Jellyfish are not fish at all. They evolved millions of years before true fish. The oldest conulariid scyphozoans appeared between 635 and 577 million years ago in the Neoproterozoic of the Lantian Formation, a 150-meter-thick sequence of rocks deposited in southern China. 

Others are found in the youngest Ediacaran rocks of the Tamengo Formation of Brazil, c. 505 mya, through to the Triassic. Cubozoans and hydrozoans appeared in the Cambrian of the Marjum Formation in Utah, USA, c. 540 million years ago.

I have seen all sorts of their brethren growing up on the west coast of Canada. I have seen them in tide pools, washed up on the beach and swam amongst thousands of Moon Jellyfish while scuba diving in the Salish Sea. Their movement in the water is marvellous.  

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, jellyfish are known as ǥaǥisama.

The watercolour ǥaǥisama you see here in dreamy pink and white is but one colour variation. They come in blue, purple, orange, yellow and clear — and are often luminescent. They produce light by the oxidation of a substrate molecule, luciferin, in a reaction catalyzed by a protein, luciferase.

Wednesday 17 December 2014

Monday 17 November 2014

Thursday 30 October 2014

KOALA: BABY JOEY

Koala, Phasscolarctos cinereus, are truly adorable marsupials native to Australia. These cuddly "teddy bears" are not bears at all. Koalas belong to a group of mammals known as marsupials. 

Fossil remains of Koala-like animals have been found dating back 25 million years. Some of the relatives of modern koalas were much larger, including the Giant Koala, Phascolarctos stirtoni

It should likely have been named the Robust Koala, instead of Giant, but this big boy was larger than modern koalas by about a third. Phascolarctos yorkensis, from the Miocene, was twice the size of the modern koalas we know today. Both our modern koalas and their larger relatives co-existed during the Pleistocene, sharing trees and enjoying the tasty vegetation surrounding them.