2005 GCSSEPM Foundation Ed Picou Fellowship Grant for Graduate Studies in the Earth Sciences Recipient Stacie Blair University of Nebraska Lincoln Nannofossil biostratigraphy of the Smoky Hill Member (Niobrara formation) type area in western Kansas and the proposed Boundary Stratotype Section for the Coniacian/Santonian boundary at Ten Mile Creek (Dallas County, Texas) Late Cretaceous Western Interior Seaway Sedimentation At its greatest extent, the Western Interior Seaway stretched its waters south to the Gulf of Mexico and north to the Arctic Ocean. It spanned westward to Utah and lapped against the sandy shores eastward onto Iowa (Bralower et al., 1998). In total, it stretched from north to south 3,000 miles and from west to east more than 1,000 miles (Kauffman, 1970). Today, there is no body of water equivalent to the Western Interior Seaway. Its surface waters stemmed from three different sources; the Gulf of Mexico, the Artic, and from freshwater river systems draining from the Sevier Orogenic Mountain system (e.g. Hay et al., 1993; Kauffman and Caldwell, 1993). The Smoky Hill Member of the Niobrara Formation accumulated during the late Cretaceous at a time when the depositional environment of the Western Interior Seaway was a benthic, soupy ooze ranging in depth between 150-300 meters (Hattin, 1982). The lithology is a well-laminated to non-laminated impure chalk consisting primarily of coccoliths (whole individuals, debris and fecal pellets), foraminifers, and invertebrate remains (Hattin, 1982). The productive wealth of fossils within the Smoky Hill Member of the Niobrara Formation has been explored and researched by invertebrate and vertebrate paleontologists for over 100 years (Hattin, 1981). The Niobrara Formation is most renowned for its rich marine
vertebrate collection, however, microfossil diversity and preservation is striking, yet only recently has been the subject of notable study and research. Within the last decade, the Niobrara Formation s nannofossils have slowly gained publicity for their exquisite preservation and their aid in the paleoecological reconstruction of the Western Interior Seaway (Watkins et al., 1993). The pristine nature of these nannofossils has appeared on the cover of the Journal of Nannoplankton Research in 1994. These sediments have also yielded intact coccospheres (a spheroidal collection of calcareous nannofossils) of at least nine different species (Covington, 1985). The delayed interest for biostratigraphic study of the Niobrara Formation is believed to be due to minor, problematic differentiations between marker beds and the lack of fine-scale stratigraphic correlation (Watkins et al., 1993). The Niobrara rocks of the Western Interior Seaway lack a fine-scale nannofossil biostratigraphy (Bralower et al., 1998). Preliminary studies conducted by Watkins (1986), Watkins (1989), and Fisher et al. (1994) have applied the use of nannofossils to infer surface-water circulation patterns of the Western Interior Seaway (Bralower et al., 1998). A stronger nannofossil biostratigraphy within the Niobrara Formation would improve distinguishing difficulties among marker beds and characterize disconformities within the formation. Hattin (1975) was the first to note dischroneity within the Niobrara Formation spanning from northwestern Kansas to northeastern Nebraska and can be seen within the nannofossil biostratigraphy. Examination of nannofossil assemblages and specific paleoecological markers would provide new information about the paleooceanography of the Western Interior Seaway. Coniacian/Santonian Boundary of the Smoky Hill Member The Western Standard Zonation defines the Coniacian/Santonian Stage boundary as the first occurrence of Scaphites depressus, a cephalopod (Hattin, 1982). However, when Hattin (1982) described the type area of the Smoky Hill Member in western Kansas he found a very poor record of almost all scaphites, and therefore could not be used as useful markers. Hattin (1982) used the presence of Inoceramus (Volviceramus) grandis (an inoceramid) as a marker for the Upper Coniacian/Lower Santonian units. The Santonian Working Group (SWG) suggests the FAD of an ammonite, Cladoceramus undulatoplicatus (Roemer), as the marker for the Coniacian/Santonian Stage boundary; however, a strong biostratigraphy has yet to be completed. Lack of refined biostratigraphy has inhibited the formal proposal of a Boundary Stratotype Section, but section areas put forward are the Olazagutia Quarry (Navarra, Spain), the Seaford Head (Sussex, England), and Ten Mile Creek (Dallas, Texas) (Lamolda et al., 1996).
Nannofossil biostratigraphy still lacks the refinement for the definition of the Coniacian/Santonian boundary. Sissingh s (1977) zonational scheme places the FAD of Micula decussata as a late Coniacian biohorizon and the FAD of Reinhardtites anthophorus as a late early Santonian biohorizon (See Figure 1) (Watkins et al., 1993). The Western Standard Zonation for the Coniacian/Santonian Stage boundary lacks a marker that is isochronous across the Western Interior Seaway. Other zonational methods that utilize Inoceramus (Volviceramus) grandis or Micula decussata are not very accurate because their first occurrences take place prior to the Coniacian/Santonian Stage boundary. Age Western Interior Standard Zonation (Hattin, 1982) Hattin (1982) Zonation Nannofossil Zonation (Watkins et al., 1993) Smoky Hill Late Santonian Desmoscaphites bassleri Desmoscaphites erdmanni Inoceramus (Endocostea) balticus s.l. Lucianorhabdus cayeuxi Member Middle Santonian Early Santonian Late Coniacian choteauensis vermiformis saxitonianus Scaphites depressus Scaphites ventricosus choteauensis vermiformis Inoceramus (Cladoceramus) undulatoplicatus Inoceramus (Volviceramus) grandis Reinhardtites anthophorus Micula decussata Marthasterites furcatus Figure 1 Zonational schemes for the Smoky Hill Member in the type area (Western Kansas) Research Utilizing sediment taken from the Smoky Hill Member in the western Kansas type area and the proposed boundary stratotype section in Ten Mile Creek (Dallas, Texas) my research would be to examine the nannofossils at the
Coniacian/Santonian boundary and create a strong nannofossil biostratigraphy for the boundary. (Figures 2 & 3) Figure 2 Map of study area in Kansas Figure 3 Map of study area in Texas Assessments of the calcareous nannofossils will give insight into suggested disconformities in the Smoky Hill type area (Covington, 1986) as well as provide data for the formal proposal of the Ten Mile Creek area as a Boundary Stratotype Section. Also, as noted by Hattin (1975), the propensity for diachroneity within the nannofossils between these two locations is strong and will offer evidence for paleoecological differences between the type area and the proposed Boundary Stratotype Section. Surface water properties and nutrient levels will also enhance development for paleoenvironmental reconstruction for the south and central Western Interior Seaway. Methods Sediment from the original collection conducted by Hattin (1982) in the type area of Kansas is already available for study and was sampled at 1-meter intervals. Smear slides have also been prepared for these samples. Another collection of the type area in Kansas was taken at 10-cm intervals and, thus, will be examined near the Coniacian/Santonian boundary similarly. Smear slides of this sediment will need to be prepared. Samples will be collected from Ten Mile Creek (Dallas County, Texas) near Lake Waxahachie (32º 20 N, 96º 48 W). They will be taken at 10-cm intervals nearest to the Coniacian/Santonian Stage boundary and at larger intervals above and below. The samples will be studied in accordant nature with the type area sediment.
Abundance analysis of nannoplankton species will be measured from both locations. Percent abundance counts and biostratigraphic correlation between sample locations will be used to determine isochroneity of nannoplankton species between the two areas. Abundance and diversity data will also be used to infer surface water conditions and paleoecology of the type area and the proposed Boundary Stratotype Section. Additionally, previous zonational scheme markers will be noted and compared. This project is an effort to provide data for naming the Ten Mile Creek area as a Boundary Stratotype Section for the Coniancian/Santonian Stage boundary. References Bralower, T.J., and J.A. Bergen, 1998, Cenomanian-Santonian calcareous nannofossil biostratigraphy of a transect of cores drilled across the Western Interior Seaway, in Stratigraphy and Paleoenvironments of the Cretaceous Western Interior Seaway, USA, No. 6: SEPM Concepts in Sedimentology and Paleontology, p. 59-77. Covington, J.M., 1985, New morphologic information on Cretaceous nannofossils from the Niobrara Formation (Upper Cretaceous) of Kansas: Geology, v. 13, p. 683-686. Covington, J.M., 1986, Upper Cretaceous nannofossils from the Niobrara Formation of Kansas Biostratigraphy and cell paleomorphology: unpublished M.S. thesis, Florida State University, 88 p. Fischer, C.G., W.W. Hay and D.L. Eicher, 1994, Oceanic front in the Greenhorn Sea (late middle through late Cenomanian): Paleoceanography, v. 6, p. 879-892. Hattin, D.E., 1975, Stratigraphic study of the Carlile-Niobrara (Upper Cretaceous) unconformity in Kansas and northeastern Nebraska, in Caldwell, W.G.E., ed., The Cretaceous System in the Western Interior of North America: Geological Association of Canada, Special Paper 13, p. 31-54. Hattin, D.E., 1981, Petrology of the Smoky Hill Chalk Member, Niobrara Chalk (Upper Cretaceous) in the type area, western Kansas: AAPG Bulletin, v. 65, p. 831-849. Hattin, D.E., 1982, Stratigraphy and depositional environments of the Smoky Hill Chalk Member, Niobrara Chalk (Upper Cretaceous) in the type area, western Kansas: Kansas Geological Survey, Bulletin 255, 108 p.
Hay, W.W., D.L. Eicher, and R. Diner, 1993, Physical oceanography and water masses in the Cretaceous Western Interior Seaway, in Caldwell, W.G.E., and Kauffman, E.G., eds., Evolution of the Western Interior Basin: St. Johns, Geological Association of Canada Special Paper 39, p. 297-318. Kauffman, E.G., 1970, Populations systematics, radiometrics, and zonation a new biostratigraphy: Proceedings No. American Paleontological Convention, pt. F, p. 612-666, 10 text-figs. Kauffman, E.G., and W.G.E. Caldwell, 1993, The Western Interior Basin in space and time, in Caldwell, WG.E., and Kauffman, E.G., eds., Evolution of the Western Interior Basin: St. Johns, Geological Association of Canada Special Paper 39, p. 1-30. Lamolda, M.A., and J.M. Hancock, 1996, The Santonian Stage and substages, in Rawson, P.F, A.V. Dhondt, J.M. Hancock and W.J Kennedy, Proceedings Second International Symposium on Cretaceous Stage Boundaries, Brussels, 8-16 September 1995, 118 p. Sissingh, W., 1977, Biostratigraphy of Cretaceous calcareous nannoplankton: Geologie Mijnbouw 57, p. 433-440. Watkins, D.K., 1986, Calcareous nannofossil paleoceanography of the Cretaceous Greenhorn Sea: Geological Society of America Bulletin, v. 97, p. 1237-1249. Watkins, D.K., 1989, Nannoplankton productivity fluctuations and rhythmicallybedded pelagic carbonates of the Greenhorn Limestone (Upper Cretaceous): Palaeogeography, Palaeoclimatology, Palaeoecology, v. 74,p. 75-86. Watkins, D.K., T.J. Bralower, J.M. Covington, and C.G. Fisher, 1993, Biostratigraphy and paleoecology of the Upper Cretaceous calcareous nannofossils in the Western Interior Basin, North America, in Caldwell, W.G. E., and Kauffman, E.G., eds.,evolution of the Western Interior Basin: St. Johnson, Geological Association of Canada Special Paper 39, p. 521-537.
BUDGET PROPOSAL Lab Supplies Budget Product Cost Amount Total Smear Slides 10.85 4 43.40 Wash Bottles 27.85 1 27.85 Beaker Cups 67.09 1 67.09 Whirl-Pak Sample Bags 85.40 1 85.40 Razor Blades 15.96 3 47.88 Thin Section Plastic Slide Box 15.48 3 46.44 Norland Optical Adhesive 47.00 2 94.00 Thin Section Glass Covers 15.72 3 47.16 Total $459.22 *Prices taken from VWR International Catalog (2003-2004) Smear Slide Preparation Slide Preparation Hourly Cost Number of Hours Total 7.00 240 1680.00 Total $1680.00 Field Work Costs Hotels Kansas 4 nights $40 per night 160.00 Food - Kansas 5 days $25 per day 125.00 Hotels Texas 6 nights $40 per night 240.00 Food Texas 7 days $25 per day 175.00 Field Assistant Wages Wages: $7/hr 40 hours 280.00 Total $980.00 *Hotels and Food Prices taken from GSA Fuel Cost for Lab Work Trip Miles Miles Per Gallon Cost Per Gallon Total Round Trip from Lincoln to Dallas County, Texas 1420 18 2.00 157.78 Round Trip from Lincoln to Logan County, Kansas 620 18 2.00 68.89 Total $226.67 Total Cost Estimated Type Cost Lab Supplies Budget 459.22 Slide Preparation 1680.00 Field Work Costs 980.00 Fuel Cost for Lab Work 226.67 Total $3345.89