Mt. St. Helens and Peat Layering


Peat Layering:

The enormous floating mass of millions of trees within Spirit Lake has afforded geologists the chance to see what would happen to just such a formation over time

  • Sure enough, bark and branches alike have been shed by the trees as they float along, are subjected to constant friction against one another and endure the weather
  • As a result, a layer of peat is beginning to form in places along the lake bottom
  • In some places, the layering is several inches thick 1

“The Spirit Lake peat resembles, both compositionally and texturally, certain coal beds of the eastern United States, which also are dominated by tree bark and appear to have accumulated beneath floating log mats.” 2

Peat layering is the first of four steps in the formation of coal beds 3


Image Source

Stage One: Peat Formation

  • When plant material (such as bark and wood) accumulates in large quantities under water, it will not fully decompose if oxygen is in limited supply
  • The incomplete decomposition leads to an accumulation of peat – a soft, fibrous, spongy substance in which plant remains are still evident

Stage Two: Lignite Formation

  • As the peat is subjected to increased vertical pressure (due to the collection of sediments above it), lignite may then form
  • This too has plant remains still evident, but begins to take on a dark brown appearance

Stage Three: Bituminous Coal

  • Known as “soft coal”, bituminous coal is formed as continued added pressure compacts the lignite
  • At this point, there is virtually no trace of the original plant visible to the eye
  • This is one of the world’s abundant fuel supplies

Stage Four: Anthracite Coal

  • Also known as “hard coal”, anthracite is formed as a result of combined pressure and high temperature
  • This hard material has a high luster, burning with a short flame and little smoke 4


Image Source

  • You wonder what would have happened to the world’s forests after the Flood of Noah
  • It makes sense that what is taking place in Spirit Lake on a micro scale, would have happened on a massive scale due to such a cataclysm 5
  • This image (above) is of a massive coal mine located in West Virginia