I need a beach geologist!

[jim kitchen]

Dear Annie,

The current mountains along the British Columbia coastline are believed to be formed by a larger island that existed several eons ago off the British Columbia coast, where this large island subducted under the North American Plate, creating the mountains we enjoy from Alaska to approximately the Washington State and British Columbia border today. The Canadian mountains are believed to be formed completely, and very differently geologically, compared to the mountain chains found along the western side of the United States because of this presumed former large island off the British Columbia coastline, compared to volcanic geological events south of the border.

Therefore, geological layers would more than likely be exposed from previous deposits of oceanic sediments, and previous carboniferous deposits...

As a side note, the Canadian portion of the Rocky Mountains is also believed to be presented more than one once, during their cyclical geological history prior to the large island crashing into the North American Plate. Portions of Western Canada, along the entire length of the Canadian Rockies leeward side, have salt layers that are four hundred to eight hundred metres thick, and they are found at depths greater than 1000 metres below the current surface. These salt layers can be possibly explained by trapped evaporating oceans, caused by continuous plate tectonic action along the west coast, where plate tectonics created the rising mountains trapping the saltwater and allowing the evaporation event to begin, geological time eroded the previous mountain sets allowing each salt layer to be covered with quietly deposited fine sedimentary shale like material, therefore separating the deposited salt layers.

Please forgive my vague overview and explanation, but I am remembering faded text from my university days where I studied geology, coastal geomorphology, and glaciology as a distraction from my Architectural studies. Then again, maybe my memory has faded...

jim k

[Nathan Potter]

Ole is probably on the right track with a form of coal. Does it smell of sulfur when you heat it? How thick is the deposit? If it is very thin and slightly lighter than coal it could be a compressed layer of volcanic ash.

Nate Potter, Austin TX.

[Ole Tjugen]

I suspect it's a thin layer in the tertiary sediments; thus not very hard or very sulfurous. It would most likely be lighter than "ordinary" older coal.

[Annie M.]

The layer is only a few inches thick and smells slightly sweet and organic... that may perhaps be because it is usually beneath the sea.

Anyway I did find a mention of 'sea coal' used as a pigment in the late 1600's in the Pigment Conpendium so I am going to give it a try for an image of that place... I can add it to my collection of things where the photograph is made using the thing itself... so far this has been trees and plants... this will be my first landscape in the series if it works.

[Brian Vuillemenot]

Sounds like lignite to me- an earlier stage of coal than the commercially mined varieties of bituminous and anthracite, and much less dense.

[walter23]

Old thread I know (I was looking through Annie's posts to see if there were any posted images), but I found some really interesting stuff on the east coast of the island this week - a bunch of hardened lava flow material (not sure if pumice is the correct type of rock - you can see the bubbles and rivulet surfaces on this stuff! Very cool)... and also a mid-sized rock containing what looks like real gold, perhaps intermixed with a bit of pyrite (these little veins are *very* yellow and amorphous, now the sort of brown / cubic look of pyrite).

On the subject of rock hounds and fossil collectors - I'm got mixed opinions. It ruins the aesthetic of an area, so I don't really like it, but on the bright side, intrusions with a rock pick can only really scratch the surface and in ten thousand years when we're all dead and gone new layers of fossils will erode out and become exposed.... so in the long term, no harm done, by this kind of casual surface stuff anyway. Open pit mines and stuff might be a different issue, those will probably be around for a very long time!

[Annie M.]

Checking me out to see if I am good enough to be in the boy's club are ya! click on my profile and you will see the only image I have on this site... a sad little scan but my first.

[walter23]

Checking me out to see if I am good enough to be in the boy's club are ya! click on my profile and you will see the only image I have on this site... a sad little scan but my first.

Haha, there's no judge or jury in this group

Just curiosity!

[PenGun]

You can find veins of hard clay too. Some of it is nearly black.

[sanking]

I assume that folks on Vancouver already know this, but if anyone does not coal mining was a very big industry around Nanaimo from the mid-19th century until recent times. Nanaimo is on the southeast coast of the island, about 30 miles west of Vancouver, separated by the Strait of Georgia.

There was also some coal mining in the past on Gabriola Island, just to the east of Nanaimo in the Strait of Georgia. I have often seen sedimentary rock layers on Gabriola that looked like coal to me.

Sandy King