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Ordovician Carbonates in Northwest Lewis and Parts of Southeast Jefferson

Counties

Andrews, JTeacherBlock 1

Purpose Statement

• Using field data collected personally and with other geologists from 2003 field season.

• “Rework” the complicated naming system that is defined previously.

Introduction• Collecting field data (via walking waterways)• Naming system used incorrectly.• Rocks in this area were formed underway and

have fossils in the rocks.

Titus 1986 and Isachsen 2000Harvard Geology department

Methods• All researchers including myself walked rock

outcrops where ever possible.• Measurements of the formations made with

Jacobs Staff• All data recorded, faults, dipping layers and

fauna

Results

• Rock layers were described by Johnsen (1971) and Walker (1973) based mainly on formation thickness and fauna.

• Discuss results of methods of research• Any possible issues with the research?

Discussion

• Formational ID new• What are your conclusions from your

research?• What are the results of this research?• Compare results to you purpose statement

Age

FormationLithology &

Contact Description

Average Thickness (m) FuanaSystemSeries

Group

Middle Ordovici

an

Mohawkian

Trenton

Hillier (Cobourg)

Base: See top of Stueben Ls, mostly Micritic. Top: Erosional surface capped by phosphatic rich beds.

8

Hormotoma, Fusispira, Conularia trentonensi, Rafinesquina deltoidea

Steuben (Cobourg)

Base: base of criniodal grainstone that has no Shale interbeds Top: Sparry grainstone grading to micritic packstone. Contact can span over 1m. 8

Rafinesquina deltoidea, Triarthrus eatoni, Climacograptus

Denley (Denmark)

Base: Shale beds increase to 5-8cm. Ls increase and are micritic Top: Shale interbeds disappear, top is defined by last shale interbed

10-50 uncertian

Cryptolithus, Paraspora, Trocholites, Rafinesquina, Hormotoma, Resserela

Sugar River (Shoreham)

Base: Ls beds decrease to (5-8cm) and are sparry. Contact sharp to gradational Top:Defined by Base of Denley 14-22

Trocholites, Cryptolithus, Prasopora

Kings Falls (Kirkfield)

Base: lowest in series of 12-25cm thick beds contianing para-ripples Top: Bed thickness decreases but still variable.

14-20

Triplesia, Sowerbyella, Cryptolithus pora orientalis, Rafinesquina, Parastrophina

Napanee (Rockland)

Base: thin to thick, grey to brown calcilutites interbedded with shale, Basel beds are often graded (disconformity) Top: Beds become more sparry and fosiliferous.

4-16

Doleroides ottawanus, Triplesia cuspidata, Paucicrura-Dalmanella rogata, Sowerbyella

Triarthrus

Cryptolithus

Trilobites

Prasopora

Sowerbyella

Age

FormationLithology &

Contact Description

Average Thickness (m) FuanaSystem

Series

Group

Middle Ordovic

ian

Mohawkian

Black River

Watertown (Chaumont)

Base:Base of thick to massive weathering Ls beds. Top: Top of a set of thck to massive weathering Ls containing Chert nodules

6

(chephalopods) Actinoceras tenuifilum, Endoceras, Gojioceras, Tetradium fibratum

Lowville

Base: Top of Pamelia Top: Dark grey micritic Ls containing Gastropods

8-18

Phytopsis tubulosa, Hormotoma sp.

Pamelia

Base: arkosic conglomerate or Ss or Dolostone. (nonconformity) Top: where a 3.0m interval has a dolostone/Ls ratio of 1:1, also placed at top of last dolostone bed. 6-10

Tetradium syringoporoides,

PreCambrian Gniess ??  

Brachiopods

Conclusion

• Work done by Kay (1930’s) was correct and properly cited, thus must be used (ACSN 1982).

• Future research included mapping of faults for natural gas and the use of radiometric dating.

References • American Commission on stratigraphic Nomenclature,

1982, note1 –Organization and objectives of the Stratigraphic Commission: American Association of Petroleum Geologists Bulletin, v. 31, no. 3, p. 513-518.

• Chenoweth, A. P. 1952. Statistical methods Applied to Trentonian Stratigraphy in New York. Bulletin of the Geological Society of America. Volume 63, pp. 521-560.

• Cushing, H. P. 1908. Lower portion of the Paleozoic sections in northwestern New York. Geological Society of America. Bulletin 19: 155-176.

• Fisher, D. W. 1962. Correlation of the Ordovician rocks of New York State. New York State museum and science service. Map and chart series 3.

• Folk, R.L., 1962, Spectral subdivisions of limestone types, in W.E. Ham (ed.), classification of carbonate rocks: American Association of Petroleum Geologists Mem. 1 p. 62-84.

• Isachsen, W. Y., Landing, E., Lauber, M. J., Rickard, V. L., Rogers, B. W.. 2000. Geology of New York, A simplified account. Second edition. New York State Museum.

• Johnsen, H. J. 1971. The Limestones of Jefferson County, New York. N.Y. State Museum and science service. Map and chart series 13.

• Kay, G. M. 1933. The Ordovician Trenton Group in Northwestern New York: Stratigraphy of the lower and upper limestone formations. American Journal of Science.

• Kay, G. M. 1937 Stratigraphy of the Trenton group. Geological Society of America. Bulletin 48 pp. 233-302.

• Titus, R. Fossil Communities of the Upper Trenton Group (Ordovician) of New York State. Journal of Paleontology. Volume 60, no. 4, pp. 805-824. 1986.

• Walker, K.R. 1973. Stratigraphy and Environmental Sedimentology of Middle Ordovician Black River Group in the Type Area- New York State. N.Y. State Museum and science service. Bulletin 419.

• Winder, C. G. 1960. Paleoecological interpretation of Middle Ordovician statigraphy in southern Onartio, Canada. Ordovician and Silurian stratigraphy and correlations. Inter. Geol. Cong., Copenhagen, Denmark 21: 18-27.