Marcellus Formation and Needmore Shale, undivided

Marcellus Formation (part of Millboro Shale): predominantly gray-black to black thinly laminated non-calcareous pyritic shale. Contains one or more thin-bedded limestones, including the Purcell Member of Pennsylvania. Needmore Shale (part of Onesquethaw ("Onondaga") Group): predominantly dark grey or green, calcitic, mostly non-fissile shale. Gives strong "kick" on gamma ray logs. Tioga Bentonite near the top. Includes the black Beaver Dam Shale Member. Grades westward into the Huntersville Chert. Not mappable at scale of this map. Included with Dmn.
State West Virginia
Name Marcellus Formation and Needmore Shale, undivided
Geologic age Devonian
Lithologic constituents
Major
Sedimentary > Clastic > Mudstone > ShaleMarcellus Formation (part of Millboro Shale): predominantly gray-black to black thinly laminated non-calcareous pyritic shale. Needmore Shale (part of Onesquethaw ("Onondaga") Group): predominantly dark grey or green, calcitic, mostly non-fissile shale
Minor
Sedimentary > Clastic > Mudstone > Shale > Black-shaleMarcellus Formation (part of Millboro Shale): predominantly gray-black to black thinly laminated non-calcareous pyritic shale. Needmore Shale (part of Onesquethaw ("Onondaga") Group): predominantly dark grey or green, calcitic, mostly non-fissile shale
Sedimentary > Carbonate > Limestone (Bed)Marcellus Formation (part of Millboro Shale): contains one or more thin-bedded limestones, including the Purcell Member of Pennsylvania.
Incidental
Sedimentary > Clastic > Mudstone > Claystone > BentoniteNeedmore Shale (part of Onesquethaw (""Onondaga"") Group): Tioga Bentonite near the top.
Comments Printed map has no indiviual description for this unit and no name, but has individual symbol and color. Only uses brackets to combine Dm and Needmore Shale. Dmn is used in digital map, so combined Dm and Needmore Shale together and called this the "Marcellus Formation and Needmore Shale, undivided". Combined thickness: Northeastern 275-1055 ft, Western 170 ft, Southeastern 100-300 ft
References

Cardwell, D.H., Erwin, R.B., and Woodward, H.P., 1968 (slightly revised 1986), Geologic Map of West Virginia: West Virginia Geological and Economic Survey, Map 1, East Sheet, scale 1:250,000.

NGMDB product
Counties Berkeley - Grant - Hampshire - Hardy - Mineral - Morgan - Pendleton