The Oella Formation is a Late Proterozoic or early Cambrian schist in Howard and Baltimore Counties, Maryland. It is described as "Medium-grained biotite-plagioclase-muscovite-quartz schist, locally garnetiferous, interlayered on a centimeter to decimeter scale with fine-grained biotite-plagioclase-quartz gneiss, commonly bearing muscovite but less commonly garnet."[2]

Oella Formation
Stratigraphic range: Late Proterozoic or early Cambrian
Outcrop of Oella Formation located on hillside east of Governor Martin Court, Ellicott City
TypeMetamorphic
Unit ofWissahickon Group
Sub-unitsSweathouse Amphibolite Member
OverliesLoch Raven Schist
Lithology
PrimarySchist and gneiss
OtherAmphibolite
Location
RegionPiedmont of Maryland
Country United States
ExtentHoward and Baltimore Counties
Type section
Named forOella, Maryland
Named byWillam P. Crowley, Juergen Reinhardt, and Emery T. Cleaves[1]
Year defined1976

Type locality

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The type locality is along the Patapsco River at Oella, southwest Baltimore County.[1]

See also

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References

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  1. ^ a b Crowley, W.P., Reinhardt, Juergen, and Cleaves, E.T., 1976, Geologic map of the White Marsh quadrangle, Maryland: Maryland Geological Survey, Quadrangle Geologic Map QA-4, scale 1:24,000. (online)
  2. ^ Crowley, W.P. and Reinhardt, Juergen, 1980, Geologic map of the Ellicott City quadrangle, Maryland: Maryland Geological Survey, scale 1:24,000. (online)