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

Wednesday, 17 December 2014

Monday, 17 November 2014

Wednesday, 12 November 2014

Thursday, 18 September 2014

PETRIFIED WOOD

Petrified wood is amazing to behold in person. The original tree or branch is sometimes subjected to such a high degree of replacement that it is impossible to tell from the original at first glance. But fossilized it is. All of the original cells are replaced one by one with minerals, often a silicate such as quartz, leaving the original cell structure intact.



And while there is often amazing preservation of the big woody bits, the telltale leaves that help us identify that wood to species are often lost. If this is the case, we add our best guess at the genus and add xlon. So, Palmoxylon is the indeterminate wood of a palm, though we may never know which palm. If you have an interest in botany and fossils, you may want to consider making a career of it. The study of fossil wood is called palaeoxylology. And a palaeoxylologist is someone who studies fossil wood.

Thursday, 21 August 2014

Tuesday, 29 July 2014

Sunday, 27 July 2014

Tuesday, 22 July 2014

AMMONITES & MARINE REPTILES FROM THE MYSTERIOUS CREEK FORMATION

The Cretaceous-Jurassic exposures near Harrison Lake, British Columbia are an easy two hour drive from Vancouver and another hour or so to our final destination, the unyielding siltstone of the Callovian, 166 million year old, Mysterious Creek Formation.

A few hours of collecting yield multiple bivalves, ammonites, including what looks to be two new species. 

Amongst the best specimens of the day are several small, fairly well preserved Cadoceras (Paracadoceras) tonniense, a few Cadoceras (Pseudocadoceras) grewingki and two relatively complete specimens of the larger, smooth Cadoceras comma. Further up the road, we photograph blocks of buchia and large boulders encrusted with perfectly preserved belemnites from ancient squid.

Interestingly, the ammonites from here are quite similar to the ones found within the lower part of the Chinitna Formation, Alaska and Jurassic Point, Kyuquot, on the west coast of Vancouver Island. The siltstone here at Harrison has also offered up a small section of vertebra from a poorly preserved marine reptile, a find I'm rather keen to make one day. So, after much hammer swinging, I've enjoyed a splendid day, collected beautiful specimens and feel a wee bit closer to the big find. 

Sunday, 13 July 2014

TYLOSTOMA TUMIDUM

This lovely big fellow is Tylostoma tumidum, an epifaunal grazing Lower Cretaceous Gastropod from white, micritic, coarsely nodular limestone deposits of the Goodland Formation at White Settlement west of Fort Worth, Texas, USA. (171.6 to 58.7 Ma). The bedding here is massive with some thin clay beds. The macro fossil found here include the ammonite, Oxytropidoceras acutocarinatum, pelecypods such as Protocardia, Pinna and Lima wacoensis along with heart-shaped urchins in abundance and lovely gastropods such as this beauty, Tylostoma tumidum.

Tylostoma have thick, smooth shells with a moderately elevated spire. Their aperture is ovato-lunate with the lips meeting above at a sharp angle. The outer lip is furnished internally, running the whole length and ending with a thickened edge. This specimen shows the wear and tear of erosion common at the site.

Saturday, 5 July 2014

LIVING FOSSIL: COMB JELLY

Living Fossil / Comb Jelly / Ctenophore
This lovely invertebrate is a Comb Jelly, a living fossil. Coined by Charles Darwin, the term “living fossils” is used to describe organisms that have remained largely unchanged for millions of years. While simple in design, the Comb Jellies have stood the test of time. The color you see here is light refracting on rows of Mertensia ovum.

Wednesday, 21 May 2014

Saturday, 3 May 2014

ISOGRAPTUS MAXIMUS

This fellow is the graptolite, Isograptus cf. maximus, from the Piranha Formation, Middle Ordovician (Dapingian), Bolivia.

Graptolites (Graptolita) are colonial animals. The biological affinities of the graptolites have always been debatable. Originally regarded as being related to the hydrozoans, graptolites are now considered to be related to the pterobranchs, a rare group of modern marine animals.

The graptolites are now classed as hemichordates (phylum Hemichordata), a primitive group which probably shares a common ancestry with the vertebrates.

In life, many graptolites appear to have been planktonic, drifting freely on the surface of ancient seas or attached to floating seaweed by means of a slender thread. Some forms of graptolite lived attached to the sea-floor by a root-like base. Graptolite fossils are often found in shales and slates. The deceased planktonic graptolites would sink down to and settle on the sea floor, eventually becoming entombed in the sediment and are thus well preserved.

Graptolite fossils are found flattened along the bedding plane of the rocks in which they occur. They vary in shape, but are most commonly dendritic or branching (such as Dictoyonema), saw-blade like, or "tuning fork" shaped (such as Didymograptus murchisoni).

This fellow is pure "Bat Sign" with his showy "wings" looking like something out of a DC Comic. He's also received a nod as the Panem symbol in Hunger Games and been described as having eagle or angel wings. No matter how you interpret his symbolism, there is not doubt that he is spectacular. He is in the collection of the deeply awesome Gilberto Juárez Huarachi from Tarija, Bolivia.

Friday, 14 February 2014

Tuesday, 21 January 2014

Friday, 17 January 2014

Wednesday, 15 January 2014

Monday, 6 January 2014

NORTHWEST BAY, VANCOUVER ISLAND

Northwest Bay is located just south of Parksville on Vancouver Island. It is a lovely place to go for a fossil day trip. Purchase a local map to help with directions. Turn east off the Island Highway onto Northwest Bay Road. Continue for 3 km and then turn left onto Wall Beach Road, which ends in a parking area up a short hill. Take the trail to the beach.  

The first beds you'll encounter are yellow-brown sandstones with trigonid bivalves. Overlying these beds are fossiliferous, gritty blue-grey shales with bivalves, gastropods, ammonites and crustaceans.  You’ll want to check the tide tables to arrive for low tide.

Sunday, 5 January 2014