Hi Jay,
The geological mapping here is not as detailed as in the U.S., so I can't establish anything more specific than 'metasedimentary' for my bedrock. It may have been sandstone, limestone, mudstone, siltstone, etc but it's been cooked and contorted well beyond recognition and is not a candidate for cleaving.
Based on indicator plants, I'm thinking my soil ph is more on the acidic side (blueberries, Labrador Tea, black spruce,etc). I'm not sure if the 'hard water' terminology my neighbour used was technically correct but they were emphatic about their whites coming out of the laundry process looking non-white.
Partly what I find appealing in the Wofati/Oehler style of construction is the drastically reduced exposure of the structure and the resulting protection from the elements. I replaced the shingles on my roof a year ago and made note of the absurdity of placing several thousand dollars worth of material in the direct path of the sun, snow and rain and knowing full well that the clock is ticking the moment it's installed. Having a roof that is self-regenerating soil and plant matter seems so much more sensible.
So, how do you feel about earthbags? Owen Geiger seems to think it's a perfect match for my ineptitude. I'm thinking that a combination of Oehler, Wofati and earthbag could produce something reasonably natural, durable, efficient and frugal.
Mike