Hostname: page-component-848d4c4894-m9kch Total loading time: 0 Render date: 2024-06-08T07:45:40.026Z Has data issue: false hasContentIssue false

Cambrian–Ordovician boundary in the Taconic allochthon, eastern New York, and its interregional correlation

Published online by Cambridge University Press:  20 May 2016

Ed Landing*
Affiliation:
New York State Geological Survey, The State Education Department, Albany 12230

Abstract

Cambrian–Ordovician boundary interval dendroid graptolites and conodonts occur in continental slope facies in the Taconic allochthon. The upper part of the Hatch Hill Formation has lowest Ordovician (lowest Tremadocian) nematophorous dendroid and lower Fauna B-aspect conodont assemblages with Cordylodus caseyi (emend.) and Iapetognathus preaengensis. Comparable dendroid-conodont faunas occur in Baltoscandia, northeastern China, and western Newfoundland; this suggests that no diachroneity can be demonstrated between the lowest occurrences of Rhabdinopora flabelliformis in a number of faunal provinces.

A practical and correlatable Cambrian–Ordovician boundary stratotype horizon defined by the lowest occurrence of a Rhabdinopora flabelliformis assemblage within an interval with lower Fauna B-aspect conodonts is advocated. A biostratigraphic horizon defined by conodonts has far less utility due to strong lithofacies-conodont biofacies linkages, unresolved problems with the species-level taxonomy of cordylodans, and possible diachronous first-appearances of Cordylodus species. Because the areally most extensive Cambrian–Ordovician boundary sequences are siliciclastic-dominated (Avalonian, Baltoscandian, Gondwanan-Hercynian platforms and shale-dominated slope sequences), the lowest local occurrence of R. flabelliformis assemblages provides a practical and traditional definition for the base of the Ordovician System and Tremadocian Series in regions where conodonts are rare or recoverable only with difficulty.

Strata correlative with the Cambrian–Tremadocian boundary interval are not represented across most of Laurentia. In this region, the “Sauk III Subsequence” locally has an important unconformity within it, and lower Tremadocian-equivalent rocks can unconformably overlie units as low as the Proterozoic. The earliest Ordovician featured a relatively simple eustatic history characterized by an “early Tremadocian onlap”; no compelling evidence supports a eustatic fall-rise couplet, or “Black Mountain eustatic event,” in this interval. Available stratigraphic information is reinterpreted to demonstrate an initially slow and subsequently higher rate of continued sea level rise in the Cambrian–Ordovician boundary interval.

Type
Research Article
Copyright
Copyright © The Paleontological Society 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Aparisi, M. 1984. Stratigraphy and structure of the Ganson Hill area: northern Taconic allochthon. Unpubl. , State University of New York at Albany, 128 p.Google Scholar
Apollonov, M. K., Chugaeva, M. N., Dubinina, S. V., and Zhemchuzhikov, V. G. 1988. Batyrbay section, south Kazakhstan, U.S.S.R.—potential stratotype for the Cambrian–Ordovician boundary, p. 445449. In Norford, B. S. (ed.), Cambrian–Ordovician Boundary Issue. Geological Magazine, 125:323–473.Google Scholar
Bagnoli, G., Barnes, C. R., and Stevens, R. K. 1987. Lower Ordovician (Tremadocian) conodonts from Broom Point and Green Point, western Newfoundland. Bollettino della Societa Paleontologica Italiana, 25:145158.Google Scholar
Barnes, C. R. 1988. The proposed Cambrian–Ordovician global boundary stratotype and point (GSSP) in western Newfoundland, Canada, p. 381414. In Norford, B. S. (ed.), Cambrian–Ordovician Boundary Issue. Geological Magazine, 125:323–473.CrossRefGoogle Scholar
Bassett, M. G., and Dean, W. T. (eds.). 1982. The Cambrian–Ordovician boundary: Sections, Fossil Distributions, and Correlations. National Museum of Wales Geological Series No. 3, 227 p.Google Scholar
Berg, R. R., and Ross, R. J. Jr. 1959. Trilobites from the Peerless and Manitou formations, Colorado. Journal of Paleontology, 33:106119.Google Scholar
Bergström, S. M., and Sweet, W. C. 1966. Conodonts from the Lexington Limestone (Middle Ordovician) of Kentucky. Bulletins of American Paleontology, 50:271414.Google Scholar
Berry, W. B. N. 1959. Graptolite faunas of the northern part of the Taconic area, p. 6173. In Zen, E. (ed.), Stratigraphy and structure of west-central Vermont and adjacent New York. 51st Annual New England Intercollegiate Geological Congress, Rutland, Vermont, 87 p.Google Scholar
Berry, W. B. N. 1961. Graptolite fauna of the Poultney Slate. American Journal of Science, 259:223228.Google Scholar
Berry, W. B. N. 1962. Stratigraphy, zonation, and age of Schaghticoke, Deepkill, and Normanskill Shales, eastern New York. Geological Society of America Bulletin, 73:695718.Google Scholar
Betz, F. Jr. 1939. Geology and mineral deposits of the Canada Bay area, northern Newfoundland. Newfoundland Geological Survey Bulletin 16, 29 p.Google Scholar
Bird, J. M., and Rasetti, F. 1968. Lower, Middle, and Upper Cambrian faunas in the Taconic sequence of eastern New York: stratigraphic and biostratigraphic significance. Geological Society of America Special Paper 113, 66 p.Google Scholar
Brown, L. L., Kelly, W. M., and Landing, E. 1984. Magnetic results from carbonate rocks from central New York State: possible remagnetization. Geological Society of America Abstracts with Programs, 16:4.Google Scholar
Bruton, D. L., Koch, L., and Repetski, J. E. 1988. The Naersnes section, Oslo region, Norway: trilobite, graptolite and conodont fossils reviewed, p. 451455. In Norford, B. S. (ed.), Cambrian–Ordovician Boundary Issue. Geological Magazine, 125:323–473.CrossRefGoogle Scholar
Bucher, W. H. 1957. Taconic klippe: a stratigraphic-structural problem. Geological Society of America Bulletin, 68:657674.Google Scholar
Bulman, O. M. B. 1932. A Monograph of British Dendroid Graptolites, Part III. Palaeontological Society, London, p. xxxiiilx, 65–94 [issued in 1934].Google Scholar
Bulman, O. M. B. 1950. Graptolites from the Dictyonema shales of Quebec. Quarterly Journal of the Geological Society of London, 106:6399.Google Scholar
Bulman, O. M. B. 1954. The graptolite fauna of the Dictyonema shales of the Oslo region. Norsk Geologisk Tidsskrift, 33:140.Google Scholar
Bulman, O. M. B. 1972. New Dictyonema fauna from the Salmian of the Stavelot massif. Bulletin d'Societe Beige du Geologie, Paleontologie et Hydrologie, 79:213224.Google Scholar
Chen, J.-Y., Qian, Y.-Y., Zhang, J.-M., Lin, Y.-K., Yin, L.-M., Wang, Z.-H., Wang, Z.-Z., Yang, J.-D., and Wang, Y.-X. 1988. The recommended Cambrian–Ordovician global boundary stratotype of the Xiaoyangqiao section (Dayangcha, Jilin Province), China, p. 415444. In Norford, B. S. (ed.), Cambrian–Ordovician Boundary Issue. Geological Magazine, 125:323–473.Google Scholar
Chen, Q.-L., Qian, Y.-Y., Lin, Y.-K., Zhang, J.-M., Wang, Z.-H., Yin, L.-M., and Erdtmann, B.-D. 1985. Study on Cambrian–Ordovician Boundary Strata and its Biota in Dayangcha, Hunjiang, Jilin, China. China Prospect Publishing House, Beijing, 138 p.Google Scholar
Cooper, R. A. 1979. Sequence and correlation of Tremadoc graptolite assemblages. Alcheringa, 3:719.Google Scholar
Destombes, J., Hollard, H., and Willifert, S. 1985. Lower Palaeozoic rocks of Morocco, p. 91336. In Holland, C. H. (ed.), Lower Palaeozoic Rocks of the World. Vol. 4. Lower Palaeozoic of Northwestern and West-Central Africa. Wiley and Sons, New York.Google Scholar
Druce, E. C., and Jones, P. J. 1971. Cambro-Ordovician conodonts from the Burke River structural belt, Queensland. Commonwealth of Australia Bureau of Mineral Resources, Geology and Geophysics Bulletin 110, 159 p.Google Scholar
Druce, E. C., Shergold, J. H., and Radke, B. M. 1982. A reassessment of the Cambrian–Ordovician boundary section at Black Mountain, western Queensland, Australia, p. 193209. In Bassett, M. B. and Dean, W. T. (eds.), The Cambrian–Ordovician Boundary: Sections, Fossil Distributions, and Correlations. National Museum of Wales Geology, Series 3.Google Scholar
Eichenberg, W. 1930. Conodonten aus dem Culm des Harzes. Paläontologisches Zeitschrift, 12:177182.Google Scholar
Erdtmann, B.-D. 1982. A re-organization and proposed phylogenetic classification of planktic Tremadoc (Early Ordovician) dendroid graptolites. Norsk Geologisk Tiddskrift, 62:121145.Google Scholar
Erdtmann, B.-D. 1986. Early Ordovician eustatic cycles and their bearing on punctuations in early nematophorid (planktic) graptolite evolution, p. 139152. In Walliser, O. H. (ed.), Global Bio-Events. Lecture Notes in Earth Sciences, Springer Verlag, New York.Google Scholar
Erdtmann, B.-D. 1988a. Graptolite-based correlation of earliest Ordovician in eastern North American marginal sequences with coeval successions in northern China and Oslo, Norway, p. 3342. In Landing, E. (ed.), The Canadian Paleontology and Biostratigraphy Seminar. New York State Museum Bulletin 462.Google Scholar
Erdtmann, B.-D. 1988b. The earliest Ordovician nematophorid graptolites: taxonomy and correlation, p. 327328. In Norford, B. S. (ed.), Cambrian–Ordovician Boundary Issue. Geological Magazine, 125:323–473.Google Scholar
Erdtmann, B.-D., and Miller, J. F. 1981. Eustatic control of lithofacies and biofacies changes near the base of the Tremadocian, p. 7881. In Taylor, M. E. (ed.), Short Papers for the Second International Symposium on the Cambrian System. United States Geological Survey Open File Report 81–743.Google Scholar
Ethington, R. L., and Clark, D. L. 1981. Lower and Middle Ordovician conodonts from the Ibex area, western Millard County, Utah. Brigham Young University Geology Studies, 28(2), 155 p.Google Scholar
Fisher, D. W. 1961. Stratigraphy and structure in the southern Taconics (Rensselaer and Columbia Counties, New York), p. D10D27. In LaFleur, R. L. (ed.), Guidebook to Field Trips. New York State Geological Association 33rd Annual Meeting, Troy, New York.Google Scholar
Fisher, D. W. 1962. Correlation chart of the Ordovician rocks in New York State. New York State Museum Map and Chart Series, 3.Google Scholar
Fisher, D. W. 1977. Correlation of Hadrynian, Cambrian, and Ordovician rocks in New York State. New York State Museum Map and Chart Series No. 25, 75 p.Google Scholar
Fisher, D. W. 1984. Bedrock geology of the Glens Falls–Whitehall region, New York. New York State Museum Map and Chart Series No. 35, 58 p.Google Scholar
Fisher, D. W., and Mazzullo, S. J. 1976. Lower Ordovician (Gasconadian) Great Meadows Formation in eastern New York State. Bulletin of the Geological Society of America, 57:14431448.Google Scholar
Fortey, R. A., Landing, E., and Skevington, D. 1982. Cambrian–Ordovician boundary sections in the Cow Head Group, western Newfoundland, p. 95129. In Bassett, M. G. and Dean, W. T. (eds.), The Cambrian–Ordovician Boundary: Sections, Fossil Distributions, and Correlations. National Museum of Wales, Geological Series No. 3.Google Scholar
Friedman, G. M. 1979. Sedimentary environments and their products: shelf, slope, and rise of Proto-Atlantic (Iapetus) Ocean, Cambrian and Ordovician Periods, eastern New York State, p. 4786. In Friedman, G. M. (ed.), Joint Annual Meeting of New York State Geological Association and New England Intercollegiate Geological Association, Rensselaer Polytechnic Institute, Troy, New York.Google Scholar
Geukens, F. P. M., and Schmidt, W. 1952. Über eine gemeinsame Exkursion durch das Kambrosilur des Hohen Venn. Geologisches Jahrbuch, 67:6772.Google Scholar
Groom, T. 1902. The sequence of the Cambrian and associated beds of the Malvern Hills. Quarterly Journal of the Geological Association of London, 58:89135.Google Scholar
Hall, J. 1851. New genera of fossil corals. American Journal of Science, Series 2, 11:398401.Google Scholar
Hall, J. 1858. Descriptions of Canadian graptolites. Geological Society of Canada, Report for 1857:111145.Google Scholar
Henningsmoen, G. 1957. The trilobite family Olenidae. Norske Videnskaps-Akademie i Oslo Skrifter, Matematisk-Naturvissenschaften, Klasse 1, 303 p.Google Scholar
Henningsmoen, G. 1973. The Cambrian–Ordovician boundary. Lethaia, 6:423439.Google Scholar
Jaanusson, V. 1979. Ordovician, p. A136A166. In Robison, R. A. and Teichert, C. (eds.), Treatise on Invertebrate Paleontology, Part A, Introduction: Fossilization, Taphonomy, Biogeography, and Biostratigraphy. Geological Society of America and University of Kansas Press, Lawrence.Google Scholar
Jacobi, R. D. 1981. Peripheral bulge—a causal mechanism for the Lower–Middle Ordovician unconformity along the western margin of the northern Appalachians. Earth and Planetary Sciences Letters, 56:245251.Google Scholar
James, N. P., and Stevens, R. K. 1986. Stratigraphy and correlation of the Cambro-Ordovician Cow Head Group, western Newfoundland. Geological Survey of Canada Bulletin 366, 143 p.Google Scholar
Jones, P. J. 1971. Lower Ordovician conodonts from the Bonapart Gulf Basin and the Daly River Basin, northwestern Australia. Bureau of Mineral Resources, Australia, Bulletin 117, 80 p.Google Scholar
Kaljo, D., Heinsalu, H., Mens, K., Puura, I., and Viira, V. 1988. Cambrian–Ordovician boundary beds at Tonismagi, Tallinn, north Estonia, p. 457463. In Norford, B. S. (ed.), Cambrian–Ordovician Boundary Issue. Geological Magazine, 125:323–473.Google Scholar
Keith, A. 1932. Stratigraphy and structure of northwestern Vermont. Washington Academy of Sciences Journal, 22:357379, 393–406.Google Scholar
Keith, B. D., and Friedman, G. M. 1977. A slope-fan-basin-plain model, Taconic sequence, New York and Vermont. Journal of Sedimentary Petrology, 47:12001247.Google Scholar
Kurtz, V. E. 1981. The Cambrian–Ordovician boundary in Missouri as determined by conodonts, p. 115117. In Taylor, M. E. (ed.), Short Papers for the Second International Symposium on the Cambrian System. U.S. Geological Survey Open-File Report 81–743.Google Scholar
Landing, E. 1977. Prooneotodustenuis (Müller, 1959) apparatuses from the Taconic allochthon, eastern New York: construction, taphonomy, and the protoconodont “supertooth” model. Journal of Paleontology, 51:10721084.Google Scholar
Landing, E. 1979. Studies in Late Cambrian–Early Ordovician conodont biostratigraphy and paleoecology, northern Appalachian region. Unpubl. Ph.D. dissertation, University of Michigan, Ann Arbor, 308 p.Google Scholar
Landing, E. 1981. Conodont biostratigraphy and thermal color alteration indices of the upper St. Charles and lower Garden City Formations. U.S. Geological Survey Open-File Report 81–740, 22 p.Google Scholar
Landing, E. 1983. Highgate gorge: Upper Cambrian and Lower Ordovician continental slope deposition and biostratigraphy, northwestern Vermont. Journal of Paleontology, 57:11491187.Google Scholar
Landing, E. 1988a. Cambrian–Ordovician boundary in North America: revised Tremadocian correlations, unconformities and “glacioeustasy,” p. 4858. In Landing, E. (ed.), Canadian Paleontology and Biostratigraphy Seminar. New York State Museum Bulletin 462.Google Scholar
Landing, E. 1988b. Depositional tectonics and biostratigraphy of the western portion of the Taconic allochthon, eastern New York State, p. 96110. In Landing, E. (ed.), The Canadian Paleontology and Biostratigraphy Seminar. New York State Museum Bulletin 462.Google Scholar
Landing, E. 1990. Conodont lithofacies-biofacies associations and a graptolite-based standard for the Cambrian–Ordovician boundary, p. 127. In Repina, L. N. and Zhuravlev, A. J. (eds.), Third International Symposium on the Cambrian System, Abstracts. Academy of Sciences of the U.S.S.R., Novosibirsk.Google Scholar
Landing, E., and Barnes, C. R. 1981. Conodonts from the Cape Clay Formation (Lower Ordovician), southern Devon Island, Arctic Archipelago. Canadian Journal of Earth Sciences, 18:16091628.Google Scholar
Landing, E., Barnes, C. R., and Stevens, R. K. 1986. Tempo of earliest Ordovician graptolite faunal succession: conodont-based correlations from the Tremadocian of Quebec. Canadian Journal of Earth Sciences, 23:19281949.Google Scholar
Landing, E., Ludvigsen, R., and Von Bitter, P. H. 1980. Upper Cambrian to Lower Ordovician conodont biostratigraphy and biofacies, Rabbitkettle Formation, District of Mackenzie. Royal Ontario Museum Life Sciences Contributions 126, 42 p.Google Scholar
Landing, E., Taylor, M. E., and Erdtmann, B.-D. 1978. Correlation of the Cambrian–Ordovician boundary between the Acado-Baltic and North American faunal provinces. Geology, 6:7578.Google Scholar
Landing, E., Westrop, S. R., and Knox, L. 1991. “Layer cake stratigraphy” of the Tribes Hill Formation (Lower Ordovician, eastern New York—not a facies mosaic. Geological Society of America, Abstracts with Programs, 23:27.Google Scholar
Lecompte, M. 1949. Decouverte de nouveaux gites a Dictyonema dans le Tremadocíen du massif du Brabant. Bulletin du Institute des Recherches Sciences Naturelles Belgique, 25:18.Google Scholar
Legrande, P. 1973. Resultats recents sur le probleme de la limite Cambrien–Ordovicien au Sahara Algerien Septentrional. Bulletin du Societe Historie Naturelle du Africa du Nord, 64:159188.Google Scholar
Lindström, M. 1970. A suprageneric taxonomy of the conodonts. Lethaia, 3:427445.Google Scholar
Lochman, C. 1956. Stratigraphy, paleontology and paleogeography of the Elliptocephala asaphoides strata in Cambridge and Hoosick quadrangles, New York. Geological Society of America Bulletin, 67:13311396.Google Scholar
Ludvigsen, R., Pratt, B. R., and Westrop, S. R. 1988. The myth of a eustatic sea level drop near the base of the Ibexian Series, p. 6570. In Landing, E. (ed.), The Canadian Paleontology and Biostratigraphy Seminar. New York State Museum Bulletin 462.Google Scholar
Miller, J. F. 1969. Conodont faunas of the Notch Peak Limestone (Cambro-Ordovician), House Range, Utah. Journal of Paleontology, 43:413439.Google Scholar
Miller, J. F. 1978. Upper Cambrian and lowest Ordovician conodont faunas of the House Range, Utah, p. 133. In Miller, J. F. (ed.), Upper Cambrian to Middle Ordovician conodont faunas of western Utah. Southwest Missouri State University Geoscience Series 5.Google Scholar
Miller, J. F. 1980. Taxonomic revisions of some Upper Cambrian and Lower Ordovician conodonts with comments on their evolution. University of Kansas Paleontological Contributions, 99, 39 p.Google Scholar
Miller, J. F. 1984. Cambrian and earliest Ordovician conodont evolution, biofacies, and provincialism, p. 4368. In Clark, D. L. (ed.), Conodont Biofacies and Provincialism. Geological Society of America Special Paper 196.Google Scholar
Miller, J. F. 1988. Conodonts as biostratigraphic tools for redefinition and correlation of the Cambrian–Ordovician boundary, p. 349362. In Norford, B. S. (ed.), Cambrian–Ordovician Boundary Issue. Geological Magazine, 125.Google Scholar
Miller, J. F., Taylor, M. E., Stitt, J. H., Ethington, R. L., Hintze, L. F., and Taylor, J. F. 1982. Potential Cambrian–Ordovician boundary stratotype sections in the western United States, p. 155180. In Bassett, M. G. and Dean, W. T. (eds.), The Cambrian–Ordovician Boundary: Sections, Fossil Distributions, and Correlations. National Museum of Wales, Geological Series No. 3.Google Scholar
Moberg, J. C. 1900. Nya bidrag till utredning af fragen om gransen mellan undersilur och kambrium. Geologiska Föreningens i Stockholm Förhandlingar, 22:532540.Google Scholar
Müller, K. J. 1959. Kambrische Conodonten. Deutsches Geologische Gesellschaft Zeitschrift, 111:431485.Google Scholar
Müller, K. J. 1973. Late Cambrian and Early Ordovician conodonts from northern Iran. Geological Survey of Iran, Report No. 30, 77 p.Google Scholar
Müller, K. J., Nogami, Y., and Lenz, H. 1974. Phosphatische Ringe als Mikrofossilien im Altpaläozoikum. Palaeontographica Abteilung A, 146:7999.Google Scholar
Ni, S.-H., Wang, X.-F., Xu, G.-H., Zhou, T.-M., Zeng, Q.-L., Li, Z.-H., Xiang, L.-W., and Lai, C.-G. 1985. Cambrian–Ordovician boundary at Huanghuachang, Yichang, Hubei, China. Bulletin of the Yichang Institute of Geology and Mineralogy, 6:7992.Google Scholar
Nicoll, R. S. 1990. The genus Cordylodus and a latest Cambrian–earliest Ordovician conodont biostratigraphy. BMR Journal of Australian Geology and Geophysics, 11:529558.Google Scholar
Nicoll, R. S., and Shergold, J. H. 1991. Revised Late Cambrian biostratigraphy at Black Mountain, Georgina Basin, Australia. BMR Journal of Australian Geology and Geophysics, 12:93118.Google Scholar
Norford, B. S. (ed.). 1988a. Cambrian–Ordovician boundary issue. Geological Magazine, 125:323473.Google Scholar
Norford, B. S. (ed.). 1988b. Introduction to papers on the Cambrian–Ordovician boundary, p. 323326. In Norford, B. S. (ed.), Cambrian–Ordovician Boundary Issue. Geological Magazine, 125:323–473.Google Scholar
North American Commission on Stratigraphic Nomenclature. 1983. North American stratigraphic code. American Association of Petroleum Geologists Bulletin, 67:841875.Google Scholar
Palmer, A. R. 1981. Subdivision of the Sauk Sequence, p. 160162. In Taylor, M. E. (ed.), Short Papers for the Second International Symposium on the Cambrian System. United States Geological Survey Open-File Report 81–743.Google Scholar
Pander, C. H. 1856. Monographie der fossilen Fische des silurischen Systems der Russisch-Baltischen Gouvernements. Akademie der Wissenschaften, St. Petersburg, 91 p.Google Scholar
Pitman, W. C. III. 1978. Relationship between eustasy and stratigraphic sequences of passive margins. Geological Society of America Bulletin, 89:13891403.Google Scholar
Powell, L. H. 1935. A study of the Ozarkian faunas of southeastern Minnesota. The Science Museum of the St. Paul Institute, 1:2559.Google Scholar
Radke, B. M. 1978. Carbonate sedimentation in tidal and epeiric environments and diagenetic overprints: the Ninmaroo Formation (Upper Cambrian–Lower Ordovician), central Australia. Unpubl. Ph.D. dissertation, Rensselaer Polytechnic Institute, Troy, New York, 329 p.Google Scholar
Repetski, J. E. 1988. Ordovician conodonts from the Bliss Sandstone in its type area, west Texas. New Mexico Bureau of Mines and Mineral Resources Memoir, 44:123127.Google Scholar
Rowley, D. B., and Kidd, W. S. F. 1981. Stratigraphic relationships and detrital composition of the medial Ordovician flysch of western New England: implications for the tectonic evolution of the Taconic orogeny. Journal of Geology, 89:199218.CrossRefGoogle Scholar
Rowley, D. B., Kidd, W. S. F., and Delano, L. L. 1979. Detailed stratigraphic and structural features of the Giddings Brook slice of the Taconic allochthon in the Granville area, p. 186242. In Friedman, G. M. (ed.), Joint Annual Meeting of New York State Geological Association and New England Intercollegiate Geological Association, Rensselaer Polytechnic Institute, Troy, New York.Google Scholar
Ruedemann, R. 1902. The graptolite (Levis) facies of the Beekmantown formation in Rensselaer County, New York. New York State Museum Bulletin, 52:546575.Google Scholar
Ruedemann, R. 1942. Geology of the Catskill and Kaaterskill quadrangles, Part 1, Cambrian and Ordovician geology of the Catskill quadrangle. New York State Museum Bulletin, 331:1188.Google Scholar
Rushton, A. W. A. 1976. Cambrian–Ordovician boundary in Wales. 25th International Geological Congress, Sydney, 11 p.Google Scholar
Skevington, D. 1966. The lower boundary of the Ordovician System. Norsk Geologisk Tidsskrift, 46:111119.Google Scholar
Stauffer, C. R. 1925. The Jordan Sandstone. Journal of Geology, 33:699713.Google Scholar
Taylor, M. E., and Landing, E. 1982. Biostratigraphy of the Cambrian–Ordovician transition in the Bear River Range, Utah and Idaho, western United States, p. 181191. In Bassett, M. G. and Dean, W. T. (eds.), The Cambrian–Ordovician Boundary: Sections, Fossil Distributions, and Correlations. National Museum of Wales Geological Series No. 3.Google Scholar
Taylor, M. E., and Repetski, J. E. 1985. Early Ordovician eustatic sea level changes in northern Utah and southeastern Idaho, p. 335. In Kerns, J. G. and Kerns, R. L. Jr. (eds.), Orogenic patterns and stratigraphy of north-central Utah and southeastern Idaho. Utah Geological Association Publication 14, 1985 Field Conference Guidebook.Google Scholar
Theokritoff, G. 1959. Stratigraphy and structure of the Taconic sequence in the Thorn Hill and Granville quadrangles, p. 5370. In Zen, E. (ed.), Stratigraphy and structure of west-central Vermont and adjacent New York. Guidebook to 51st Annual Meeting of the New England Intercollegiate Geological Conference, Rutland, Vermont.Google Scholar
Theokritoff, G. 1964. Taconic stratigraphy in northern Washington County, New York. Geological Society of America Bulletin, 75:171190.Google Scholar
Tjernvik, T. E. 1958. The Tremadocian beds at Flagabrö in southeastern Scania (Sweden). Geologiska Föringens i Stockholm Förhandlingar, 80:259276.Google Scholar
Tomczykowa, E. 1968. Stratigraphy of the uppermost Cambrian deposits in the Swietokrzyskie Mountains. Proceedings of the Institute of Polish Geology, 54:185 [in Polish].Google Scholar
Vail, P. R., Mitchum, R. M., and Thompson, S. III. 1977. Seismic stratigraphic and global changes of sea level, Part 3: relative changes of sea level from coastal onlap, p. 6381. In Payton, E. (ed.), Seismic Stratigraphy—Application to Hydrocarbon Exploration. American Association of Petroleum Geologists Memoir 26.Google Scholar
van Wamel, W. A. 1974. Conodont biostratigraphy of the Upper Cambrian and Lower Ordovician of north-western Öland, south-eastern Sweden. Utrecht Micropaleontological Bulletins, 10, 128 p.Google Scholar
Wanenmacher, J. M., Twenhofel, W. H., and Raasch, G. O. 1934. The Paleozoic strata of the Baraboo area. American Journal of Science, 28:130.Google Scholar
Westergaard, A. H. 1909. Studier öfver Dictyograptusskiffern och dess gränslager. Lunds Universitat Arsskrifter N. F., 5(3), 79 p.Google Scholar
Westergaard, A. H. 1953. Two problematic fossils from the Upper Cambrian in Sweden. Geologiska Föringens i Stockholm Förhandlingar, 75:465468.Google Scholar
Westrop, S. R., Landing, E., and Ludvigsen, R. 1981. Upper Cambrian and Lower Ordovician trilobite and conodont biostratigraphy, Wilcox Peak, Jasper National Park, Alberta, p. 4558. In Aitken, J. D. (compiler) and Taylor, M. E. (ed.), The Cambrian System in the southern Canadian Rocky Mountains, Alberta and British Columbia. Second International Symposium on the Cambrian System, Guidebook for Field Trip 2, Denver, Colorado.Google Scholar
Whittard, F. R. 1960. Lexique Stratigraphique International du Europe (England, Wales & Scotland), Fascicule 3 a IV (Ordovician). Centre du Reserches Naturelle Scientifique, Paris, 296 p.Google Scholar
Whittington, H. B., Dean, W. T., Fortey, R. A., Rickards, R. B., Rushton, A. W. A., and Wright, A. D. 1984. Definition of the Tremadoc Series and the series of the Ordovician System in Britain. Geological Magazine, 121:1733.Google Scholar
Wignall, P. B., and Myers, K. J. 1988. Interpreting benthic oxygen levels in mudrocks: a new approach. Geology, 16:452455.Google Scholar
Williams, H. 1978. Tectonic lithofacies map of the Appalachian orogen. Memorian University of Newfoundland Map 1.Google Scholar
Zen, E. 1959. Stratigraphy and structure of the north end of the Taconic Range and adjacent areas. New England Intercollegiate Geological Conference, 51st Annual Meeting, Rutland, Vermont, p. 116.Google Scholar
Zen, E. 1964. Taconic stratigrpahic names: definitions and synonymies. U.S. Geological Survey Bulletin 1174, 95 p.Google Scholar
Zen, E. 1967. Time and space relationships of the Taconic allochthon and autochthon. Geological Society of America Special Paper 97, 107 p.Google Scholar