|Geologic age||Middle Devonian|
Sedimentary > Clastic > Mudstone > Shale
Sedimentary > Carbonate > Limestone
Sedimentary > Clastic > Sandstone
Sedimentary > Clastic > Mudstone > Shale > Black-shale
|Comments||part of Hamilton Group 200-500 ft. (60-150 m). Secondary unit descriptions from USGS Lexicon website (ref. NY046) and reference NY013, NY014, NY015, NY022: The Ludlowville Formation of western NY has been subdivided since 1930 into four members: the Centerfield Limestone (4-14 m), the Ledyard Shale (10-30 m), the Wanakah Member (12-21 m), and the Jaycox Member (<1-18 m). In central NY, the Ludlowville consists mainly of variably silty mudstones with lesser proportions of fossiliferous siltstone and sandstone. It was subdivided by Smith (1935) above the Centerfield into the Otisco Shale (50 m), the Ivy Point Siltstone (20 m), the Spafford Shale (8 m) and the Owasco Siltstone (<1-2.5 m). Recent studies have been made to correlate these units precisely. The Otisco Shale has been correlated with the black Ledyard Shale, and the Ivy Point with parts of the Wanakah Member. The Spafford and the Owasco are not so easily equated with the post-Wanakah of western NY. The Spafford was not recognized west of Owasco Lake until recently though it had been traced eastward to the Chenango Valley. The Spafford is now known to extend westward into the Cayuga and Seneca Lake region as a sparsely fossiliferous siliciclastic mudstone. It extends still farther west as a thin tongue of shale, formerly assigned to the Wanakah. It is bounded at the base by the Limerick Road Bed (new) and at the top by the Hills Gulch Bed of the Jaycox. The Jaycox extends from Syracuse westward to Elma. It is underlain by the Wanakah Member from Erie Co. eastward to East Bethany. From Genesee Co. eastward, mudstones, here assigned to the Spafford Member, are interposed between the Wanakah and the base of the Hills Gulch Bed of the Jaycox. The Owasco Siltstone Member of central NY correlates with the Hills Gulch Bed of the Jaycox of western NY (Mayer and others, 1994). Deep Run Member of Moscow Formation consists of hard bluish gray, calcareous, and typically highly bioturbated silty mudstones. Becomes a calcareous silty mudstone or siltstone with well preserved ZOOPHYCOS spreiten in eastern outcrops. Basal 0.5 to 1.5 m is richer in fossils, particularly the branching coral HELIOPHYLLUM PROLIFERUM, which is diagnostic of this interval. Also contains crinoid columns, bryozoans, gastropods, brachiopods, and trilobites. Upper beds of the Deep Run are relatively homogenous in appearance and contain only scattered fossils. Unit is thickest (18 m) at its type section on the east side of Canandaigua Lake and thins both southeastward and westward so that it appears as a large scale lens in cross section. Gradationally overlies the Tichenor Limestone Member and gradationally underlies the Menteth Limestone Member in the basin center. Age is Middle Devonian (Givetian) (Brett and Baird, 1994). In west-central NY, Tichenor Limestone Member of the Moscow Formation is a 1- to 2-ft-thick compact limestone bed. From Erie to Livingston Cos., consists of coarse crinoidal skeletal grainstone, but eastward near Canandaigua Lake, unit thickens and becomes finer-grained, represented by a styliolinid and crinoidal packstone. Represents the first transgressive limestone of the Moscow sequences. It disconformably overlies various members of the Ludlowville Formation. Upper contact is relatively abrupt in most localities where it underlies the Menteth Limestone Member, but is gradational and conformable with the Deep Run Member. Age is Middle Devonian (Givetian) (Brett and Baird, 1994). Grabau (1917) proposed the name Wanakah for the shale below the "Encrinal" of Eighteenmile Creek (Tichenor of this paper), but did not define it further. In this paper Wanakah member of Ludlowville formation is name used for the sequence beginning [below] with the STROPHULOSIA and PLEURODICTYUM beds of Grabau and terminating at top with base of Tichenor. Type section is in Wanakah and Lakewood Beach Cliffs, Lake Erie. Thus defined, it can be traced eastward to Seneca Lake. It is chiefly light and dark blue-gray shales but contains a number of thin bands of limestone (Trilobite beds), which are remarkable for their persistence for nearly 100 mi. The Wanakah member overlies Ledyard member. [Thickness of Wanakah not stated, but it appears, from section on p. 218, to range from 30 ft at Lake Erie to about 60 ft at Seneca Lake. East of Seneca Lake it corresponds to lower part of Kings Ferry member.] (Cooper, 1930). Centerfield Limestone Member of Ludlowville Shale extended from western NY into western PA and northeastern OH and into the subsurface in northern WV and westernmost MD (Garrett Co.) (de Witt and others, 1993).|
Fisher, D.W., Isachsen, Y.W., and Rickard, L.V., 1970, Geologic Map of New York State, consisting of 5 sheets: Niagara, Finger Lakes, Hudson-Mohawk, Adirondack, and Lower Hudson, New York State Museum and Science Service, Map and Chart Series No. 15, scale 1:250,000.
Brett, C.E. and Baird, G.C., 1994, Depositional sequences, cycles, and foreland basin dynamics in the late Middle Devonian (Givetian) of the Genesee Valley and western Finger Lakes region, IN Brett, C.E., and Scatterday, James, eds., Field trip guidebook: New York State Geological Association Guidebook, no. 66, 66th Annual Meeting, Rochester, NY, p. 505-585.
Mayer, S.M., Baird, G.C. and Brett, C.E., 1994, Correlation of facies divisions in the uppermost Ludlowville Formation (Givetian) across western and central New York State, IN Landing, Ed, ed., Studies in stratigraphy and paleontology in honor of Donald W. Fisher: New York State Museum Bulletin, no. 481, p. 229-264.
de Witt, Wallace, Jr., Roen, J.B. and Wallace, L.G., 1993, Stratigraphy of Devonian black shales and associated rocks in the Appalachian basin, IN Roen, J.B., and Kepferle, R.C., eds., Petroleum geology of the Devonian and Mississippian black shale of eastern North America: U.S. Geological Survey Bulletin, 1909-B, p. B1-B57.
Cooper, G.A., 1930, Stratigraphy of the Hamilton Group of New York: American Journal of Science, 5th series, v. 19, no.53, pts. 1-2, p. 116-134, 214-236.
USGS Geologic Names lexicon found at: http://ngmdb.usgs.gov/Geolex/
|Counties||Erie - Genesee - Livingston - Ontario|