Tag Archives: geology

Life from Ash and Ice: A documentary film about Mt. Edziza

Screenshot of Knowledge Network video about Mt. Edziza.

Screenshot of Knowledge Network video about Mt. Edziza. Click to go to site.

For various reasons I’ve been off work for a while and that has meant being off blogging as well. If you’ve commented on posts recently then thanks; if you’ve emailed my gmail account and still would like a reply then maybe try again.

Anyway, what better way to resume making the occasional post here than a film about the place where I did some of my first ever fieldwork: assessing the then-proposed Site Z dam site on the Stikine River in Tahltan territory, far Northwestern British Columbia, in the shadow of Mt. Edziza.  Edziza is well known to Northwest Archaeologists as one of the region’s most important sources of obsidian, a volcanic glass highly suitable for making certain kinds of stone tools.

The video, Edziza: Life from Ash and Ice, can be watched in full on the B.C. Knowledge Network’s web site.  (NB: I had to change the resolution from a default of “lousy”).  Obviously the geology of the Edziza Complex is pretty cool (and is covered in the first half of the video, which features John Clague among others), but there’s quite a bit of more direct archaeological interest in the second half.

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NW Geology Field Trips Lead to Chert?

The Aldergrove Glacial Erratic. source: geocaching.com

This is something a little different, leading to something cool: the NW Geology Blog has assembled quite a few self-guided geological fieldtrips, mostly in the Seattle to Vancouver corridor.  There are two in the Fraser Valley: the Aldergrove glacial erratic, and the Shasta erratic in Coquitlam.  The other BC field trip is to the recent, massive debris flow at Capricorn Creek.

But it was one of the Washington State trips which caught my eye though: a trip to a formation of Stilpnomelane at Blanchard Mountain, Skagit County, near Bellingham Washington.  The reason this caught my eye: the formation is intersected by massive, green chert beds.

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La Perouse at Port des Francais (Lituya Bay)

Detail of entrance of Port des Francais. Source: Brown University. Click for zoom version.

Most readers will be very familiar with Captains Vancouver and Cook and some of the other early European explorers of the Northwest Coast.  Less familiar is Jean-François de Galaup, Comte de La Pérouse, (1741-1788), who embarked on a world journey of exploration in 1785:

The French decided to mount a scientific and exploration voyage to rival that of Captain James Cook. Two ships, the Boussole and the Astrolabe, under La Perouse’s command left France in August 1785. They spent the summer of 1786 off the coasts of Alaska looking for a northwest passage then sailed down the west coast of North America in August and September 1786.

One of their most memorable and tragic periods was the time they spent in Lituya Bay, Alaska, which they called Port des Francais (map).

Lituya Bay, with Cenotaph Island in the foreground. Source; Panoramio user footsnviews.

Their mapping and illustration of Tlingit life are not unknown but also not that easy to find.  I recently came across an interesting site which has the best web presentation of these materials (actually reproduced from a 1798 British edition) I have seen: the images are highly zoomable, and the zoom is fast and crisp and smooth.  Linking to specific images is possible and the links don’t break.  With a little bit of effort, you can download the images (hint: “view source” of the page and search for ‘Size4″).  So zoom right in and see the details of pictures such as this one of a fish camp (are those halibut drying, or Pacific cod?), or this one of both a fine Tlingit dugout, and the construction of a skin vessel, with its seal skin hull removed and placed to one side.  The chart made by La Perouse is here and full of detail (again, these are English re-engravings of the originals).

While spending  time in Lituya Bay, tragedy befell the expedition. From here, an account of La Perouse’s time in Port des Francais:

1786 July Port des Francais / Lituya Bay

The next day, the narrow entrance to an inlet was located to the east of Cape Fairweather. De Pierrevert, from the Boussole, and Flassan, from the Astrolabe, were dispatched in small boats to investigate the inlet. Their favourable reports encouraged a somewhat reluctant La Pérouse to take the ships in. Their first approach was unsuccessful and they tacked offshore through the night before the tide carried them in the next morning. Even then, it was a precarious passage and the ships both nearly were driven onto rocks. They anchored just inside the entrance but La Pérouse was not happy with this spot, it having a shallow, rocky bottom. He sent men off to a find safer anchorage. D’Escures found a better location behind the large island in the inlet and the two ships transferred there. It was 3 July 1786.

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