Puneet Varma (Editor)

Harrell Formation

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Type
  
sedimentary

Country
  
United States

Region
  
Appalachian Mountains

Primary
  
Slate, Sandstone

Sub-units
  
Burket Shale Member

Named by
  
Charles Butts, 1918

Overlies
  
Brallier Formation

Roadcut of devonian brallier and harrell formations


The Devonian Harrell Formation is a mapped bedrock unit in Pennsylvania, Maryland, West Virginia, and Virginia.

Contents

Description

The Harrell Formation was first described by Charles Butts in 1918. Hasson and Dennison (1978) state "The Harrell Shale consists of very dark gray, thinly laminated, platy- to sheety-weathering shale underlain in certain areas by the grayish black shale of the Burket Member."

Fossils

Hasson and Dennison reported the following fossils from several outcrops of the Harrell:

  • Bivalvia: Buchiola livonae (?), B. retrostriata, Paracardium doris, Pterochaenia fragilis, Lunlulicardium (?)
  • Cephalopoda: Bactrites aciculum, Probeloceras lutheri
  • Cricoconarida: Styliolina fissurella

    • Notable Exposures

    Type locality is at Horrell Station, Blair County, Pennsylvania (40°27′N 78°17′W).

    Age

    Relative age dating places the Harrell in the late Devonian.

    References

    Harrell Formation Wikipedia
    (Text) CC BY-SA