Sunday, January 20, 2013

The Anthropocene Layer

Walking through a nearby city lot today, I found this shale-like mound of decomposing asphalt roof shingles, part of the thin geologic formation known as the Anthropocene layer. Geologists speculate that this layer, comprising all the sediments, debris, mineral effects and ruins of human civilizations will ultimately be a relatively thin layer of rock once it is all buried and compressed, a mere blip in the Earth's vast time frame.
The asphalt roofing reminded my of these thin shales exposed on Treasury Mountain in the Elk Mountains of Colorado at about 12,000 feet.  This outcrop of Mancos Shale is part of a ~5,000 foot thick layer of sediments that were deposited in shallow seas that flooded much of Colorado between about 145 million years ago and 65 million years ago.

Given a few million years, plus some intense heat and pressure, both the shingles and shale could be transformed into slate, a much harder type of rock that is also used for roofing!

1 comment:

Tom Pendley said...

Really cool comparison. You are amazing.