There's gold in them thar backyards.
May 21, 2010 3:05 PM Subscribe
Is there a name for the flaky, layered clay/soil deposit with a striking metallic sheen found in my childhood neighborhood in Northern Virginia?
In the neighborhood I grew up in in Burke, Virginia, which is in Fairfax County, there was an interesting clay/soil in our yards (as compared to the less interesting red-brown clay also found there). As kids we called it "fool's gold," because of its color and sheen, although obviously it was nothing like iron pyrite.
It was easy to dig up in dry, solid chunks. It could be broken into layers, like shale, so we could divide the chunks into sheets, but it was nowhere near as hard as shale. It was soft enough that we could use fist-sized chunks of it like chalk on the sidewalks, yet was firm enough that we could draw with it without it breaking much, though it was softer than chalk.
Because of the layers, I assume it was sedimentary. Some googling turned up "mudstone" - does that sound like what it was? I've long wondered if it had a particular name, if there was more to know about how it was formed, and where it is geographically distributed.