Fern Glen

Outcrops occure in the Fern Glen formation (Willman 1975) by Grafton and Valmeyer, Illinois  (Kelly 1984).  The Mississippian Aged Fern Glen formation lies under Burlington limestone.  Fern Glen is a pale yellow, pale red, (Kelly 1984) or greenish grey chert.  This nodular chert (Willman 1975) contains small fossils that vary in abundance and small crystals.  The texture of Fern Glen is medium grained with a dull to medium luster (Jackson 1992).

Upper portion of the Valmeyer Anticline at Valmeyer Illinois.

Fern Glen from Missouri.

Notice the quartz crystals in this piece of Fern Glen chert.

Types

Timeline

Bibliography