|
|
|
bedrock plain
Monday, September 15 2008
Today was sunny but the temperatures had returned to normal for the season, with highs somewhere in the 70s. In the course of trimming the bottom of the greenhouse hole's southwest corner, I managed to reach a smooth expanse of shale bedrock which was easily cleared of overburden using a square-tipped loading shovel (it acts like a small snow shovel). I managed to expose all of the shale bedrock expanse present in the hole, where it comprised about a third of the hole's bottom area. This expanse was a nearly a perfect plain and resembled a poured concrete slab. Unfortunately, though, it was not anywhere near level, sloping downward (at a grade of about 5%) towards the northwest, the corner opposite from the one my drainage trench leads from. This meant that eventually I'd have to chop a trench through that shale to provide drainage to that corner. Fortunately, the shale falls apart easily when struck by any metal tool. But I'd actually prefer it to be a bit more sturdy so it could form a solid floor for the greenhouse.
At this point in the excavation the greenhouse hole is 27 to 28 inches deep along its periphery most of the way around, though it is only about 22-24 inches deep in its center.
For linking purposes this article's URL is:
http://asecular.com/blog.php?080915 feedback
previous | next |
