geology

Stratigraphy of the Central and Northern Shenandoah Valley, and Eastern West Virginia SequenceAGEWest FORMATIONEast Thickt DESCRIPTION Interptetation

MAUCH CHUNK R GREENBRIAR

PocONO

Coarse s, silt, shole. Channels. Plant fossils

common in places, Coal_ Carbonate dominated (oolites, biosparites)

Begin Alleghenian Orogeny

Orogenic Calm

300- Quartz sandstone & conglomerate; coarse, 1700 thick, large cross beds

HAMPSHIRE GREENLAND GaP iROUP (former Chemumg). FoREKNOBS

BRALLIER

(Catskill) 2000 Point Bar Sequences; red

Thick hummocky sequences; at top interbed- ded red and green fine sonds and silts 2000 SCHEER

1500- (Portage in Pa.) 1700 Bouma sequences

MILLBORO (Used south of Shenandoah Co.)

lully Harrel Mahantango 900|

Dark gray to black silts and fine sands

Marcellus 350-500 100-

530 fossils abundant in places Olive groy fine sands, silts, and shales; NEEDMORE

M Wallbridge Uncontormity ORISKANY

Tioga bentonite

10- Quortz arenite; white, gray, Tan; 125 abundant fossils

LICKING CREEK MANDATA NEw ScoLAND70-150 cherts, or interbedded with shale or quartz

NEw CREEK 17-50| arenites; fossils very abundont KEYSER

HeLDERBERG Corbonates of many kinds; sometimes with GROUP

70-6001 50-2501 dal carbonates; ALM, ALD; mud cracks; TONOLOWAY (Salina in Wa.)

WILLS CREEK WILLIAMSPORT

McKENZIE

salt costs; evaporitic to west BLoOMSBURG 0-400| Bloomsburg: red very fine sonds/sils/shale

0-75 Yllow.calcareous shale: fossils KEEFER

RoSE HILL TusCARORA

|70|Massanutfen: coarse friable quartz orenites and conglomerates with large planar X-beds

bOU Tuscarora/Keefer: quartz arenites; ripples 50- Skolithus. Rose Hill: red fine - coarse sands

and shales; loads, ripples, frace fossils Gray

Swhite, coarse X-bedded sands

MASSA- 5 NUTTEN

250

JuNIATA L20-200 Red X-bedded s, Skolithus; bedded OsWEGO Cub Hum- SS"O-375| W/Sh_

Clastic hummocky mocky

REEDSVILLE TRENTON GROUP

Feldspathilithie Bouma sequences

Ggoy sily'shale_

MARTINSBURG 3000sequences Carbonate

Oranda 40-60| hummocky ?

-BLACK RIVER GROUP"

Liberty Hall) EDINBURG 600 Lantz Mils

Black massive micrites and shale

425-Equences_

Carbonate hummocky

SMicrites, bio- and pelmicrites, chert

sequences

25-170 LINcoLNSHIR�

NEW MARKET 40-250 bundant fossils, darkens up section_

Very pure micrites; tidal features Knox Unconformity

BEEKMANTOWN (Rockdale Run) STONEHENGE (Chepultepec) CoNOcOCHEAGUE ELBROOK ROME Waynesboro)

E SHADY

2500 | Thick bedded dolomite, black chert; tidal 500 Thick bedded micrite, blve; tidal features

2500 LS/dolo/qtz arenite ; abndt tidol structures 2000 LS/dolo/ blue-gray; tidal feotures 2000 Red/green shale/dolo/micrte, very voriable 1600 Dolomite (granular); LS at top and bottom 500- Qugrtz arenite; abndt X-beds

1500 Skolihus O ANTIETAM

B WEVERTON Thin bedded

shale and graded sandstones HARPERS 2000 Cs feldspathic 800 large planar

X-beds and Bouma sequiencAs

ICATOCTIN 1ALFEIRERB IIFNE 2000 Subareal tholeiti, fod basals ( ow greerschir) SwIFT RUN GRENVILLE BasEMENT

LYNCHBURG) East of Blue Ridge

L.S.Fichter, 1991 (reformatted 1996)