Tag Archives: natural clay deposits

How clay is created in nature

Earlier today, I was thinking about clay…how it is strengthened when molecules overlap. This lead to pondering the organic material itself. I’ve always been curious about how things work and this tendency led to an interest in scientific processes. So, after looking at a few sites, I came across a description about the formation of clay in entry on the Absolute Astronomy site. It included everything I needed to know. Basically, clay is created when rocks weather over long periods of time, which makes chemical changes happen. According to the entry, rocks with silica eventually create “low concentrations of carbonic acid and other diluted solvents. These solvents, usually acidic, migrate through the weathering rock after leaching through upper weathered layers.” It said that slowly forming clays present in two ways, either as a “residual deposit” or, if we’re talking about thick clay formations, then by the sedimentary process after erosion and movement shifts it from its “original location of formation.” Clays are also found in marine environments, near big lakes or by “marine deposits.”  This would explain why there is so much naturally occurring clay in my area, at the end of the Burrard Inlet in Metro Vancouver. Many creeks feed into the inlet. Just on my street, alone, five creeks intersect the four-block long lane, then head downhill to the ocean. There has been much ancient and modern-day mudslide activity here. It has left big boulders and large river-type stones above  and below ground here. Ocean water is four blocks away, at present, but I don’t know where the waterline was in ancient times. Back to clay, though. Evidently, kaolin is formed on the spot, but other clays have moved by way of water and erosion. A type of clay is determined by different ways of grouping and categorizing. This source says there are up to four main types:

  • Kaolinite
  • Montmorillonite-smectite
  • Illite
  • Chlorite (sometimes considered a phyllosilicate)

Apparently, these are further broken down into some 30 odd pure clays, but the entry says that natural clays are most often a combination. Further description states that varve is clay that shows “visible annual layers” formed as the result of seasonal changes and that it is commonly found in former glacial lakes, which it says have very little movement. As I read about clay on this site, I was particularly interested in a unique type of clay called quick clay, which is a “marine clay indigenous to the glaciated terrains of Norway, Canada, Northern Ireland and Sweden. It is a highly sensitive clay, prone to liquefaction, which has been involved in several deadly landslides.”

In any event, I answered my initial question…how is clay created in nature? I am satisfied with what I learned and if I want to investigate further, I have several avenues….

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Digging for Natural Clay Deposits

Looking at the photos of my friend Tom’s class digging natural clay deposits reminded me of how much fun I had when I did that with Mr. Carson’s class in high school. It’s very gratifying to process the clay we found and make something with it, even if it was backbreaking work. It made me think of the clay deposits in this area. A local potter once told me where to find clay here. The location is in the Chineside Park area in Port Moody. To reach it, find Hope Street, between Elgin and Douglas, then,  mid-block, head south into the Chines (see the map above). You’ll be walking up a draw on the east side of a creek. Up a ways, on the left bank, you’ll find a natural clay deposit. You’ll need buckets to haul it out and it’d be best to have several people help haul it out in buckets to make it worth your while. This clay body is tried and true, according to a reliable area potter who lives near this outcrop.

I also became curious and did a little looking into the history of clay deposits in the area and found there were several companies that processed clay in the area. One of them was Pacific Clay Products Ltd., at Pleasantside, on Port Moody’s north shore, and it closed in 1950, according to Clay and Shale Deposits, Bulletin 3o, put out by BC Dept. of Mines in 1952. The document states,”fairly extensive stratified deposits of very fine-grained highly plastic blue clay occur at several places in the area, notably Capilano, and Lynn Valleys, near Port Moody.” It goes on to say that other clay bodies had been “worked…in Port Moody” and that the color of the clay is gray or red. I will see if I can find more current information and follow up on this for us.

If you want to pursue digging your own clay in your area, you’ll need to know a bit more before you begin. I like this article from About.com: “How to Use Locals Clays in Your Pottery,” by Beth Peterson. It’s a good run down of what you’ll have to do once you find your clay deposit. She covers finding the clay, processing it, making test pieces, firing it, and testing maturation. Plus, she refers you to other links along the way. I have not followed Peterson’s instructions with the Port Moody clay I gave you directions to above, but I’m passing it on to you because About.com is a very credible source. It is my ‘go-to’ site for anything I want to look up on the internet. If you do decide to dig in your own area, make sure you are careful. Take care of your back! Wet clay is very heavy….

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