Moline

Outcrops of Moline chert appears in the Pennsylvanian Spoon formation.  Moline chert is found along the lower Rock River and in secondary drainage systems in Northwestern Illinois.  The color gradient of Moline chert extends from a blueish black to blue grey to off-white.  Small fossils which look like blue speckles are some times found in Moline chert (Birmingham 1989).  Banding can also occur (Jackson 1992).  Moline chert occurs in large tabular pieces or in chert beds.  The exterior of the tabular form generally is stained orange or red by iron oxides.  Moline chert is fine grained (Birmingham 1989) to grainy in texture (Jackson 1992).

Iron oxide staining can be seen on the lower most edge of this piece of Moline chert.  The brownish tan exterior on the upper portion of the chert is weathering caused by water.

The different colors of moline chert can be seen in this piece along with the blue fossil specks.

Iron oxide staining can bee seen on the edges of these chert flakes.

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