|All plant fossils here were found in the Llewellyn Formation (300 mya, Pennsylvanian Period) and are one of the few places where one can find these very detailed white (sometimes yellow) ferns on a striking contrast of black shale. The plants died and fell into the swamp, where in a low temperature, pressure, and oxygen environment the plant tissue was slowly replaced by pyrite (from sulphides). Pyrophyllite (aluminum silicate, a whitish mineral) is believed to have replaced the pyrite at a later stage as the sediments piled up and the temperature and pressure became greater. The ferns most commonly found are Alethopteris, Neuropteris, Pecopteris, and Sphenophyllum.
There is a proposed plan to use this world famous fossil site and the surrounding area and turn it into a landfill. Fortunately, groups like SC FORCE (a citizen formed organization to oppose the Blythe Recycling and Demolition Site "BRADS") and members of the Army for a Clean Environment have demonstrated against this plan. This landfill, proposed by Blythe Township, would adversely affect St. Clair and surrounding areas by threatening their water supply, air quality, wildlife, recreation and overall quality of life. The landfill would also greatly increase truck traffic and pollution through towns and surrounding communities. And do we really want to lost this precious fossil site? Please support there good efforts and visit the webpages below:
SC Force (Saint Clair Families Organized to Retain a Clean Environment)
Army for a Clean Environment
More photos of ferns here at:
Click the photo to enlarge.
Photos from the Rutgers Geology Museum:
1) Alethopteris - Seed Fern, 2) Neuropteris - Seed Fern, 3) Sphenophyllum, 4) Sphenopteris - Seed Fern, 5) Stigmaria - Either Lepidodendron or Sigillaria, 6) Cyclopteria - Neuropteris type Seed Fern