Tag: geology

Geology of the Dodd Lake – Horseshoe Lake area

Tom talking to group about alluvial deposits with the melting of the ice sheet
– D. Bedry
Barbara passing around a piece of granitic rock for people to see mineral deposits and crystals
– D. Bedry
Tom bringing down a piece of rock to examine
– D. Bedry
Examining a rock with a 10x loop
– D. Bedry
Pieces of rock with example of crystals and mineral deposits
– D. Bedry
Tom in his element
– J. May
One of the participants pointing out quartz veining in a dyke
– D. Bedry
A swarm of dykes
– N. Pezel
David getting the campfire going
– N. Pezel
Barbara pointing out and explaining a diyke n a roadside fault line
– D. Bedry
Just the obligatory “gang’s all here” group shot
– D. Bedry
Another angle….and a better view!
– R. Muffley

Geology of the Dodd Lake – Horseshoe Lake area
by Nancy Pezel, 21 April 2018.

Tom Koleszar and Barbara Sherriff led an enthusiastic group of 26 members on a trip to learn about the geology of the local area.

Along with some great views at our first stop, Tom gave us a brief history of glaciation in the area.  We learned that a kilometre of ice covered the area some 12-13,000 years ago.  As the ice receded glacial streams flowed down the lower slopes and valleys, layering the rounded sediments.  These sediments are exposed nicely at the gravel pit at 12 Mile on the Goat Main.

On Beaver Main we stopped at an exposed rock cut and Barbara explained the processes of mineralization.  Who knew that rotten rock is a good thing?  Donning hard hats, we were left for a bit to prospect for pyrite, chalcopyrite, Molybdenum, and other minerals.  Unfortunately no one found any gold!

We then drove further up the road to Little Horseshoe campsite where we enjoyed our lunches and warmed up around David Bedry’s campfire and the sunny dock.  Barbara told us about physically staking mineral claims the old-fashioned way, as well as the new digital “click of a mouse” method on the BC government website.

After a short walk down the road, Barbara explained about plutons and fractures and we saw swarms of hydrothermal dykes of varying colours (and more rotten rock!) before we headed back home with our treasures.

Cortes Island geology

Our mission…to circumnavigate Cortes Island…and watch for rocks! – T. Siddall
Our vessel, the lovely Misty Isles – T. Siddall
A stunning dyke on Twin Island – T. Siddall
Pictograph – T. Siddall
Buchia fossil– T. Siddall
– T. Siddall
What rock hammers are for…isn’t it cute? – T. Siddall
A buck watches our mysterious ways – T. Siddall
Stranded moon – T. Siddall
We stayed overnight at Coast Mounatin Expedition Lodge– T. Siddall
Lanny, Ralph and Cedar-the-dog – our hosts for the night – T. Siddall
View from the lodge…the setting was wonderful! – T. Siddall
The mysterious “Lucey” grave on West Redonda Island – T. Siddall
Captain Mike and the Misty. Too soon it was time to re-embark for the voyage home – T. Siddall
Xenoliths and more! With our brains full of geological insights…and puns…and packs heavier with samples! – T. Siddall

Cortes Island geology
by Tammy Siddall, 22 July 2015. 

It was a perfect July day in Lund when 12 naturalists boarded the Misty Isles in search of rocks. Captain Mike and crewmate Amy had planned an exciting two-day circumnavigation of Cortes Island for us.  From Lund Harbour we first headed north towards the Twin Islands.

As we travelled, co-leaders Barbara Sherriff & Tom Kolezar spoke about the geological formations and what we hoped to find.  We were on the lookout for dykes, which are sheets of igneous rock that form in fractures of existing rock.  We hit the mother lode arriving on Twin, where we hopped into the zodiac to head ashore.  The dykes did not disappoint!

From there we headed farther northwest around Cortes as Mike spoke to the group about Buchia, which are bivalve fossils.  His enthusiasm for Buchia was infectious and we followed a tip he had on a new specimen. It was a treasure hunt. We headed ashore and found the Buchia fossil. This was a hunt 140 million years in the making!

After a lovely lunch and some of the best cookies going, we travelled further around Cortes, learning the history of the region and spotting more dykes. With the informative rock lessons from our great leaders, no one on this trip will ever look at the shoreline the same way again.

An impromptu stop at Quartz Bay revealed a stunning dyke of quartz crystals. Tom and Barbara worked out that the existing rock setting in which the crystals formed was a sandstone while a foraging deer looked on. We even spotted a ‘cute’ dyke!

For the evening we headed to Read Island to stay at the Coast Mountain Expedition lodge. As we anchored in a bloom of moon jellyfish we knew we were in for something magical. The setting was serene and the hosts were marvelous.  As usual, the meal was awesome.  The next morning we had a lovely breakfast made by Lannie and Ralph, our lodge hosts and we were off in search of a copper and molybdenite deposit.

We travelled to the location of a stream that drains below a claim site on West Redonda Island.  Here we came ashore and we found assorted interesting cobbles including magnetite, basalt, diorite, granodiorite, and a rich sulphide. (You know the rocks are interesting when the geologists take back samples for themselves!)   Another treat at this location was the mysterious albeit beautiful gravestone belonging to two small children named Lucey.  The grave is still a mystery more than 100 years later.  The setting of the stream was idyllic and the water so clear that many of the group took time out to have a quick dip in the ocean.

Refreshed and renewed, we headed off in search of more ancestral pictographs. Mike once again regaled us with the history of the area, peppered like shiny mica, with the mystical stories as told by the area’s aboriginal communities.  After lunch, which included more of those great cookies (thanks Samantha!) we headed south towards geological formations known as xenoliths.  The xenoliths created wild patterns where they contrasted the host rock.  On our way to the xenoliths, we rounded a small island, which Mike calls Mini-Mittlenatch where we spotted many sea birds along-side seals nursing their young.

When we came into the Lund Harbour after an incredible day at sea, most of us realized our bags were much heavier than when we started.  Various rock samples of our treasure hunts were stuffed into our luggage.

For many of us on this trip the unfolding world of rocks was a new and tuff one, but after a fantastic two days we all agreed it was a blast!

 

 

Stephen Johnston – “Spain: Rocks, Romans and Rioja”

Spain is a land full of stories and story-telling, going back to Don Quixote and his horse Rocinante
– S. Johnston
and continuing through Picasso’s Guernica
Spain’s rich history pre-dates even the time of copulating Tyrannasurus Rex
– S. Johnston
It started with wandering tectonic plates…
The supercontinent Pangaea formed about 350 million years ago
That collision, and subsquent separation of continents, had far-reaching consequences
It built huge mountain ranges underlain with mineral deposits
– S. Johnston
and created fertile soils that were ideal for growing grapes
– S. Johnston
Which attracted warriers and colonists, most notably the Romans
– S. Johnston
and led to traditional garb with elements of both Orthodox Christian and Muslim influence
– S. Johnston
and led to centuries of mining, for gold, and mercury, and copper
– S. Johnston
Even today, many of the smallest things can be traced back to ancient connections to Africa and other continents
– S. Johnston
Everywhere you look, you’d be safe to assume…there’s a story behind that…
– S. Johnston
Indeed, Spain’s rich history of colonization
and wine-making
– S. Johnston
are all tied to the rocks!
– S. Johnston
food for thought…
– S. Johnston

Stephen Johnston – “Spain: Rocks, Romans and Rioja”
by Andrew Bryant, 21 May 2015. 

Dr. Stephen Johnston, professor of geology at the University of Victoria, took us on a lively and all-encompassing journey to Spain.

Based on his extensive knowledge of Pangea, that supercontinent formed by wandering tectonic plates some 350 million years ago, Stephen gave a wonderful example of how everything is always connected to everything else.

Want to find gold in Spain?  Look for apple and chestnut trees, as these were often planted by the Romans while they were looking for gold.

Want to know why Las Médulas became a World Heritage Site?  Thank Pliny the Elder, who fortuitously published his notes shortly before his death in the Mount Vesuvius eruption in 79 AD.

Why is there a Sequoia tree growing at the University of Salamanca?  Because Christopher Columbus brought seeds back from America, at the same time that loads of Spanish mercury were being shipped to the New World to be using in gold mining operations there…

In short, this was not your typical travelogue!

Tom Koleszar – “Exploring the Burgess Shale”

Anomalocaris, the “strange shrimp” that is not a shrimp at all, but makes for a lovely Cambrian poster-child
– National Science Foundation
The Burgess Shale outcrops are located near Field, British Columbia
– T. Koleszar
The sites are managed by Parks Canada, who have installed informative signs along trails in the area. This one’s at Emerald Lake
– T. Koleszar
Wapta Mountain and Fossil Ridge as see from Emerald Lake. The Walcott Quarry is in the center-right
– T. Koleszar
Here are the various quarries subseqently established in the area
– T. Koleszar
Charles Walcott in the field circa 1910
– Smithsonian Institution
This is the quarry that now bears his name
– T. Koleszar
The first Anomalocaris fossil ever recovered, now at the Royal Ontario Museum
– K. Schengili-Roberts
Anomalocaris was the largest predator of the Cambrian oceans, with some specimens up to a metre long. In this depiction it is chasing trilobites
– K. Doud
Global distribution of Burgess Shale type formations
– Virtual Museum of Canada
A lot happened in a short (by geological standards) period of time. Many phyla that emerged during the Cambrian were ultimately “failed experiments”
– Harper and Smith (2013)
Just a few of the oddballs. From left to right we have Anomalocaris, Wiwaxia, and Marella. These are all “unassigned forms”, with no clear signs of ancestral linkage to any surviving group
– T. Koleszar
This is Haplophrentis carinatus, part of another group that is long extinct
– Smithsonian
The soft-tissue level of detail preserved in the rocks is truly mind-blowing. This is a reconstruction of Marella splendens
– montage by Haug et al. (2012)
Where else can one pursue earth-shaking science amidst such splendor? Emerald Lake as seen from the Walcott quarry
– T. Koleszar
Another view of Fossil Ridge
– T. Koleszar
And if you get bored looking at rocks
– T. Koleszar
You can follow these fellows
– T. Koleszar
all the way to Stanley Glacier, and beyond!
– T. Koleszar

Tom Koleszar – “Exploring the Burgess Shale”
by Andrew Bryant, 19 Mar 2015. 

Tom Koleszar, geologist and vice-president of our club, took us on a sweeping, half-billion year-old exploration of the Burgess Shale.

This extraordinary rock formation, located in Yoho and Kootenay National Parks in the Canadian Rockies, contains one of the world’s richest deposits of fossils.  It is renowned for the quality of its fossils, especially as they allow for the preservation of soft-tissue imprints.   You can learn much more about it here, here and here.

It is truly extraordinary to look at a 500 million-year old rock and be able to count delicate hairs, eye facets or mouthpart details on an organism that was only millimetres or centimetres long when it swam or crawled through prehistoric seas.

Using photos, maps, and wit, Tom intoduced us to the fascinating world of the Cambrian, an epoch during which the oceans exploded into life.  To decribe creatures such as Anomalocaris, Hallucigenia and Opabinia as “strange” is a severe understatement – some of these things are downright weird!

There is also some fascinating human history surrounding these rocks, including that of discoverer Charles Walcott, who impressed his hardworking family into field technicians and porters, and the unresolved scientific debate between people such as Stephen Jay Gould and Simon Conway Morris.

Was the “Cambrian explosion” just a series of failed experiments in body type design?  Or the beginning of phyla that can be traced to this day?

As they say.  Time will tell.

Cortez Island Geology

Wrangelia: Triassic aged rock at Hidalgo Point on Hernando Island – M. Koleszar photo
Recent (Quaternary) sediments at the northern end of Hernando Island – M. Koleszar photo
More Quaternary sediments – M. Koleszar photo
Dipping Triassic rock layers at Echo Bay, Twin Islands – M. Koleszar photo
“What is this rock?” – the 1st question of a young geologist! – M. Koleszar photo
Grey dike cutting across host rock at Echo Bay – M. Koleszar photo
Reddish intrusive dike, Iron Point, Twin Islands – M. Koleszar photo
More dikes, with older Wrangelia sedimentary rock being examined in the background – M. Koleszar photo
How Iron Point got its name! – M. Koleszar photo
Barbara talks rocks…
…and Barbara’s rocks talked! M. Koleszar photo
A day in the field is ALWAYS better than a day in the office! – M. Koleszar photo
Quaternary sediments, Cortes Island – M. Koleszar photo
A rare Agarikon fungas, Kinghorn Island – M. Kaleszar photo
Cruising past Kinghorn Island – M. Koleszar photo
in addition to the rocks, there was some wildlfie, too (Kinghorn Island) – M. Koleszar photo
Rounding Kinghorn Island into Desolation Sound – M. Koleszar photo
The Red Point unit (biotite granite) at Cortes Bay – M. Koleszar photo
Harbour seals adorning the rocks, Copeland Islands – M. Koleszar photo
More dikes in the Coast Plutonic Complex, Copeland Islands – M. Koleszar photo
Xenoliths (fragments of older rock within an igneous body), Copeland Islands – M. Koleszar photo
More zenoliths – M. Koleszar photo

Cortez Island Geology
by Tom Koleszar, 26 July 2014.

Twelve naturalists, led by our own Barbara Sherriff, boarded the Misty Isles with Captain Mike Moore for a day-long geological tour of Hernando, Twin, and Cortes Islands.

We first cruised past Hernando Island before landing at Iron Point at the south end of Twin Islands, where we had ample opportunity the get our hands on the rocks of Wrangelia and the Coast Plutonic Complex.  Back aboard the Misty Isles, we then cruised along the south shore of Cortes Island looking at recent Quaternary sediments and more examples of the plutonic rocks of coastal BC.

For the latter part of the afternoon, Captain Mike took us on a cruise around Kinghorn Island in Desolation Sound and then along the Copeland Islands and back to Lund.  Along the way we saw some wildlife and a rare Agarikon fungas on an old growth Douglas Fir (in addition to the rocks and beautiful scenery, of course!)

We had a wonderful day with great weather, and we all learned a lot about the geology of our own area.  Special thanks to Barbara and Mike Moore for making it all possible!