Gytta

Gytta is formed from the partial decay of peat. It is black and has a gel-like consistency. Humic acid (see http://www.suprahumic.unina.it/) is formed by anaerobic bacteria in the first 0.5 meter of the peat column. The humic acid slowly drains to the bottom of the column. It pools at the bottom of the peat column, about 10 meters below the surface. Gytta accumulates as long as new material is added to the top of the column. Gytta is the part of peat that forms coal, but it must be buried under thousands of feet for coalification to occur because it has to be hot enough to drive off the water it contains.

References

• How Swamps Produce Coal