Palynomorphs and depositional environment for upper Campanian ...
nificant negative excursion in the isotopic carbon-13 isotopic signal and a negative excursion in the isotopic oxygen-18 isotopic signal among several of the Danian benthic taxa (Barrera personal communication). Similar isotopic shifts in isotopic carbon-13 and isotopic oxygen-18 occur at numerous other KIT boundary sites and have been interpreted as representing decreased oceanic productivity and increased marine temperatures, respectively (Perch-Nielson, McKenzie, and He (1982). This study was supported by National Science Foundation grants DPP 82-14174A01 to P.N. Webb and DPP 82-13985A01 to W.J. Zinsmeister and D.H. Elliot. References Askin, R.A. 1984. Palynological investigations of the James Ross Island basin and Robertson Island, Antarctic Peninsula. Antarctic Journal of the U.S., 19(5), 6-7. Barrera, E. 1986. Personal communication. Berggren, W.A. 1962. Some planktonic foraminifera from the Maestrichtian and type Danian stages of southern Scandinavia. Contributions in Geology, 9, 1-106. Hansen, H.J. 1970. Biometric studies on the stratigraphic evolution of Globoconusa daubjergensis (BrOnnimann). Bulletin of the Geological Society of Denmark, 19, 341-360. Huber, B.T. 1985. The location of the Cretaceous/Tertiary boundary on Seymour Island, Antarctic Peninsula. Antarctic Journal of the U.S., 20(5), 46-48. Huber, B.T. 1986. Foraminiferal evidence for a terminal Cretaceous oceanic event. Geological Society of America, Abstract with Programs,
18(4), 309-310. Huber, B.T., D.M. Harwood, and P.N. Webb. 1983. Upper Cretaceous
Palynomorphs and depositional environment for upper Campanian sediments on Seymour Island, Antarctica R. ASKIN
Geology Department Colorado School of Mines Golden, Colorado 80401
Seymour Island, northeastern Antarctic Peninsula, provides an area for effective study of palynomorph assemblages and their value as indicators of Cretaceous and Tertiary paleoenvironments. Paleoenvironmental interpretations can be based on a wealth of evidence from other fossil groups, coupled with sedimentological analyses. The interpretations may also be compared with previous palynological studies from other parts of the world. The essentially unconsolidated Campanian through Eocene Seymour Island sediments are well exposed and yield a plethora of fossils of many different floral and faunal 1986 REVIEW
microfossil biostratigraphy of Seymour Island, Antarctic Peninsula. Antarctic Journal of the U.S., 18(5), 72-74.
Luterbacher, H.P., and I. Premoli Silva. 1964. Biostratigraphy of the Cretaceous-Tertiary boundary in the Central Appenines Rivista Italiana di Paleontologia e Stratigrafia, 70, 67-88. (In Italian) Macellari, C. E. 1985. The Cretaceous-Tertiary boundary in the Antarctic Peninsula and southern South America. Memorias, Sexto Congreso Latinoamericano de Geologia, 267-278. (In Spanish) Macellari, G.E. 1986. Late Campanian-Maastrichtian ammonite fauna from Seymour Island (Antarctic Peninsula). Journal of Paleontology, Memoir, 18, 1-55. Macellari, CE., and W.J. Zinsmeister. 1983. Sedimentology and macropaleontology of the Upper Cretaceous to Paleocene sequence of Seymour Island. Antarctic Journal of the U.S., 18(5), 69-71. Perch-Nielsen, K., J . McKenzie, and Q. He. 1982. Biostratigraphy and isotope stratigraphy and the "catastrophic" extinction of calcareous nannoplankton at the Cretaceous/Tertiary boundary. Geological Society of America Special Paper, 190, 353-371. Pessagno, E.A., Jr. 1967. Upper Cretaceous planktonic foraminifera from the western Gulf Coastal Plain. Palaeontographica Americana, 5(37), 245-445. Smit, J. 1982. Extinction and evolution of planktonic foraminifera after a major impact at the Cretaceous/Tertiary boundary. Geological Society of America Special Paper, 190, 329-352. Troelsen, J.C. 1957. Some planktonic foraminifera of the type Danian and their stratigraphic importance. Bulletin of the U.S. National Museum, 215, 125-132. Webb, P.N. 1973. Upper Cretaceous-Paleocene foraminifera from Site 208 (Lord Howe Rise, Tasman Sea), DSDP Leg 21. In R.E. Burns, J. Andrews, et al. (Eds.), Initial Reports of the Deep Sea Drilling Project, 21, 541-573. Zinsmeister, W.J., and C. Macellari. 1983. Changes in the macrofossil faunas at the end of the Cretaceous on Seymour Island, Antarctic Peninsula. Antarctic Journal of the U.S., 18(5), 68-69.
groups. Palynomorphs, both marine and nonmarine in origin, are particularly abundant throughout the succession. The following comments on the upper Campanian part of the section exemplify some aspects of this study. Fossil and sedimentological evidence suggests a nearshore marine, low-energy depositional environment for upper Campanian sediments on Seymour Island. Beds dated as upper Campanian by calcareous nannofossils, foraminifera, ammonites and other molluscs, etc., (Huber, Harwood, and Webb 1983; Huber in preparation; Macellari 1984, 1986) and by palynomorphs (Askin 1985, in preparation) comprise the oldest sediments cropping out on Seymour Island. They are assigned to part of the Lopez de Bertodano Formation and contain a high proportion of mud and silt, particularly in massive mudstone units best developed toward the south coast (Macellari in preparation). Upper Campanian Seymour Island sediments are subdivided into six lithologic units ("Rotularia units," Macellari in preparation). The low-diversity invertebrate macrofauna is dominated by the annelid Rotularia, which apparently favored muddy substrates (Macellari 1984). In his discussion of sedimentological data and environmental/ecological preferences of the macrofauna, Macellari (in preparation) concludes that units 1 through 6 were deposited in very shallow marine, low-energy, delta/ estuary-influenced environments, with possible intermittent brackish conditions. 73
Paleoenvironmental inferences from relative abundances, morphologic features and types of palynomorphs in these sediments are consistent with Macellari's conclusions. The palynomorph assemblages studied include relatively abundant (57-91 percent) and moderately diverse nonmarine palynomorphs (pollen and spores of land-plants, freshwater algae, fungi), plus cuticle and other plant debris, sometimes in large pieces. This component is consistent with hypothesized nearshore marine depositional conditions, and a low-energy environment where large, rather delicate pieces of tissue have been preserved. A marine component, which includes dinoflagellate cysts, acritarchs, and other algal bodies, is dominated in most assemblages by periodinioid cavate dinoflagellate cysts (mainly species of Manumiella, with Alterbia, etc.). Acanthomorph acritarchs vary from less than 1 percent to 76 percent (of total assemblage). Various studies (e.g., Downie, Hussain, and Williams 1971; Harland 1973; Wallet al. 1977) have indicated the preference of peridinioid species for nearshore (to estuarinebrackish-lagoonal) conditions, with most chorate types (infrequent to rare in most Campanian samples studied from Seymour Island) predominating in offshore, more open marine conditions. Swarms of acanthomorph acritarchs have been equated with inshore, partly enclosed conditions (e.g., Wall 1965), often associated with marine transgressions (e.g., Downie et al. 1971), and Wall (1965) also correlated long, delicate spines in Jurassic acanthomorph acritarchs with an unagitated environment. The spines preserved in the Seymour Island Campanian acritarchs are long and delicate, suggesting lowenergy conditions. These acritarchs are particularly abundant (76 percent) in a sample from unit 3 deposited in a mud flat/mud tongue (Macellari in preparation) environment. Vozzhennikova (1965) has suggested a possible correlation of dinocysts with thick periphragm and endophragm with unstable, nearshore conditions. Thick walls occur in many dinocysts in Campanian samples from Seymour Island. A good example is the relatively thick periphragm of Manumiella ("Isabelidinium") n. sp. 3, the marker species and usually most abundant dinocyst in uppermost Campanian/lower Maastrichtian zone 4 samples (Askin 1985, in preparation). Once calibrated by other fossils diagnostic of narrowly defined habitats, palynomorph assemblages should useful indicators of Campanian through Eocene paleoenvironments. Pal-
74
ynomorphs are nearly ubiquitous in these Seymour sediments and will provide information for samples devoid of other fossil groups. This research is supported by National Science Foundation grant DPP 83-14186.
References Askin, R. A. 1985. Palynological studies in the James Ross Island Basin, Antarctic Peninsula: A progress report. Antarctic Journal of the U.S., 20(5), 44-45. Askin, R.A. In preparation. Campanian to Eocene palynological succession of Seymour and adjacent islands, northeastern Antarctic Peninsula. Geological Society of America, Memoir.
Downie, C., M.A. Hussain, and G.L. Williams. 1971. Dinoflagellate cyst and acritarch associations in the paleogene of southeast England. Geoscience and Man, 3, 29-35. Harland, R. 1973. Dinoflagellate cysts and acritarchs from the Bearpaw Formation (Upper Campanian) of southern Alberta, Canada. Palaeontology, 16, 665-706. Huber, B.T. In preparation. Late Cretaceous-Early Tertiary foraminifera from the James Ross Island region, Antarctic Peninsula. Geological Society of America, Memoir.
Huber, B. T., D.M. Harwood, and P.N. Webb. 1983. Upper Cretaceous microfossil biostratigraphy of Seymour Island, Antarctic Peninsula. Antarctic Journal of the U.S., 18(5), 72-74. Macellari, C.E. 1984. Revision of serpulids of the Genus Rotularia (Annelids) at Seymour Island (Antarctic Peninsula) and their value in stratigraphy. Journal of Paleontology. 58(4), 1098-1116. Macellari, C. E. 1986. Late Campanian-Maastrichtian ammonite fauna from Seymour Island (Antarctic Peninsula). Journal of Paleontology, Memoir, (Vol. 18). Macellari, C.E. In preparation. Stratigraphy, sedimentology and paleoecology of Late Cretaceous/Paleocene shelf-deltaic sediments of Seymour Island (Antarctic Peninsula). Geological Society of America, Memoir.
Vozzhennikova, T.F. 1965. Introduction to the study of fossil Peridinioid algae. Moscow: Nauka. (In Russian) Wall, D. 1965. Microplankton, pollen, and spores from the Lower Jurassic in Britain. Micropaleontology, 11(2), 151-190, Wall, D., B. Dale, G.P. Lohmann, and W.K. Smith. 1977. The environmental and climatic distribution of dinoflagellate cysts in modern marine sediments from regions in the North and South Atlantic Oceans and adjacent seas. Marine Micropaleontology, 2, 121-200.
ANTARCTIC JOURNAL
18(4), 309-310. Huber, B.T., D.M. Harwood, and P.N. Webb. 1983. Upper Cretaceous
Palynomorphs and depositional environment for upper Campanian sediments on Seymour Island, Antarctica R. ASKIN
Geology Department Colorado School of Mines Golden, Colorado 80401
Seymour Island, northeastern Antarctic Peninsula, provides an area for effective study of palynomorph assemblages and their value as indicators of Cretaceous and Tertiary paleoenvironments. Paleoenvironmental interpretations can be based on a wealth of evidence from other fossil groups, coupled with sedimentological analyses. The interpretations may also be compared with previous palynological studies from other parts of the world. The essentially unconsolidated Campanian through Eocene Seymour Island sediments are well exposed and yield a plethora of fossils of many different floral and faunal 1986 REVIEW
microfossil biostratigraphy of Seymour Island, Antarctic Peninsula. Antarctic Journal of the U.S., 18(5), 72-74.
Luterbacher, H.P., and I. Premoli Silva. 1964. Biostratigraphy of the Cretaceous-Tertiary boundary in the Central Appenines Rivista Italiana di Paleontologia e Stratigrafia, 70, 67-88. (In Italian) Macellari, C. E. 1985. The Cretaceous-Tertiary boundary in the Antarctic Peninsula and southern South America. Memorias, Sexto Congreso Latinoamericano de Geologia, 267-278. (In Spanish) Macellari, G.E. 1986. Late Campanian-Maastrichtian ammonite fauna from Seymour Island (Antarctic Peninsula). Journal of Paleontology, Memoir, 18, 1-55. Macellari, CE., and W.J. Zinsmeister. 1983. Sedimentology and macropaleontology of the Upper Cretaceous to Paleocene sequence of Seymour Island. Antarctic Journal of the U.S., 18(5), 69-71. Perch-Nielsen, K., J . McKenzie, and Q. He. 1982. Biostratigraphy and isotope stratigraphy and the "catastrophic" extinction of calcareous nannoplankton at the Cretaceous/Tertiary boundary. Geological Society of America Special Paper, 190, 353-371. Pessagno, E.A., Jr. 1967. Upper Cretaceous planktonic foraminifera from the western Gulf Coastal Plain. Palaeontographica Americana, 5(37), 245-445. Smit, J. 1982. Extinction and evolution of planktonic foraminifera after a major impact at the Cretaceous/Tertiary boundary. Geological Society of America Special Paper, 190, 329-352. Troelsen, J.C. 1957. Some planktonic foraminifera of the type Danian and their stratigraphic importance. Bulletin of the U.S. National Museum, 215, 125-132. Webb, P.N. 1973. Upper Cretaceous-Paleocene foraminifera from Site 208 (Lord Howe Rise, Tasman Sea), DSDP Leg 21. In R.E. Burns, J. Andrews, et al. (Eds.), Initial Reports of the Deep Sea Drilling Project, 21, 541-573. Zinsmeister, W.J., and C. Macellari. 1983. Changes in the macrofossil faunas at the end of the Cretaceous on Seymour Island, Antarctic Peninsula. Antarctic Journal of the U.S., 18(5), 68-69.
groups. Palynomorphs, both marine and nonmarine in origin, are particularly abundant throughout the succession. The following comments on the upper Campanian part of the section exemplify some aspects of this study. Fossil and sedimentological evidence suggests a nearshore marine, low-energy depositional environment for upper Campanian sediments on Seymour Island. Beds dated as upper Campanian by calcareous nannofossils, foraminifera, ammonites and other molluscs, etc., (Huber, Harwood, and Webb 1983; Huber in preparation; Macellari 1984, 1986) and by palynomorphs (Askin 1985, in preparation) comprise the oldest sediments cropping out on Seymour Island. They are assigned to part of the Lopez de Bertodano Formation and contain a high proportion of mud and silt, particularly in massive mudstone units best developed toward the south coast (Macellari in preparation). Upper Campanian Seymour Island sediments are subdivided into six lithologic units ("Rotularia units," Macellari in preparation). The low-diversity invertebrate macrofauna is dominated by the annelid Rotularia, which apparently favored muddy substrates (Macellari 1984). In his discussion of sedimentological data and environmental/ecological preferences of the macrofauna, Macellari (in preparation) concludes that units 1 through 6 were deposited in very shallow marine, low-energy, delta/ estuary-influenced environments, with possible intermittent brackish conditions. 73
Paleoenvironmental inferences from relative abundances, morphologic features and types of palynomorphs in these sediments are consistent with Macellari's conclusions. The palynomorph assemblages studied include relatively abundant (57-91 percent) and moderately diverse nonmarine palynomorphs (pollen and spores of land-plants, freshwater algae, fungi), plus cuticle and other plant debris, sometimes in large pieces. This component is consistent with hypothesized nearshore marine depositional conditions, and a low-energy environment where large, rather delicate pieces of tissue have been preserved. A marine component, which includes dinoflagellate cysts, acritarchs, and other algal bodies, is dominated in most assemblages by periodinioid cavate dinoflagellate cysts (mainly species of Manumiella, with Alterbia, etc.). Acanthomorph acritarchs vary from less than 1 percent to 76 percent (of total assemblage). Various studies (e.g., Downie, Hussain, and Williams 1971; Harland 1973; Wallet al. 1977) have indicated the preference of peridinioid species for nearshore (to estuarinebrackish-lagoonal) conditions, with most chorate types (infrequent to rare in most Campanian samples studied from Seymour Island) predominating in offshore, more open marine conditions. Swarms of acanthomorph acritarchs have been equated with inshore, partly enclosed conditions (e.g., Wall 1965), often associated with marine transgressions (e.g., Downie et al. 1971), and Wall (1965) also correlated long, delicate spines in Jurassic acanthomorph acritarchs with an unagitated environment. The spines preserved in the Seymour Island Campanian acritarchs are long and delicate, suggesting lowenergy conditions. These acritarchs are particularly abundant (76 percent) in a sample from unit 3 deposited in a mud flat/mud tongue (Macellari in preparation) environment. Vozzhennikova (1965) has suggested a possible correlation of dinocysts with thick periphragm and endophragm with unstable, nearshore conditions. Thick walls occur in many dinocysts in Campanian samples from Seymour Island. A good example is the relatively thick periphragm of Manumiella ("Isabelidinium") n. sp. 3, the marker species and usually most abundant dinocyst in uppermost Campanian/lower Maastrichtian zone 4 samples (Askin 1985, in preparation). Once calibrated by other fossils diagnostic of narrowly defined habitats, palynomorph assemblages should useful indicators of Campanian through Eocene paleoenvironments. Pal-
74
ynomorphs are nearly ubiquitous in these Seymour sediments and will provide information for samples devoid of other fossil groups. This research is supported by National Science Foundation grant DPP 83-14186.
References Askin, R. A. 1985. Palynological studies in the James Ross Island Basin, Antarctic Peninsula: A progress report. Antarctic Journal of the U.S., 20(5), 44-45. Askin, R.A. In preparation. Campanian to Eocene palynological succession of Seymour and adjacent islands, northeastern Antarctic Peninsula. Geological Society of America, Memoir.
Downie, C., M.A. Hussain, and G.L. Williams. 1971. Dinoflagellate cyst and acritarch associations in the paleogene of southeast England. Geoscience and Man, 3, 29-35. Harland, R. 1973. Dinoflagellate cysts and acritarchs from the Bearpaw Formation (Upper Campanian) of southern Alberta, Canada. Palaeontology, 16, 665-706. Huber, B.T. In preparation. Late Cretaceous-Early Tertiary foraminifera from the James Ross Island region, Antarctic Peninsula. Geological Society of America, Memoir.
Huber, B. T., D.M. Harwood, and P.N. Webb. 1983. Upper Cretaceous microfossil biostratigraphy of Seymour Island, Antarctic Peninsula. Antarctic Journal of the U.S., 18(5), 72-74. Macellari, C.E. 1984. Revision of serpulids of the Genus Rotularia (Annelids) at Seymour Island (Antarctic Peninsula) and their value in stratigraphy. Journal of Paleontology. 58(4), 1098-1116. Macellari, C. E. 1986. Late Campanian-Maastrichtian ammonite fauna from Seymour Island (Antarctic Peninsula). Journal of Paleontology, Memoir, (Vol. 18). Macellari, C.E. In preparation. Stratigraphy, sedimentology and paleoecology of Late Cretaceous/Paleocene shelf-deltaic sediments of Seymour Island (Antarctic Peninsula). Geological Society of America, Memoir.
Vozzhennikova, T.F. 1965. Introduction to the study of fossil Peridinioid algae. Moscow: Nauka. (In Russian) Wall, D. 1965. Microplankton, pollen, and spores from the Lower Jurassic in Britain. Micropaleontology, 11(2), 151-190, Wall, D., B. Dale, G.P. Lohmann, and W.K. Smith. 1977. The environmental and climatic distribution of dinoflagellate cysts in modern marine sediments from regions in the North and South Atlantic Oceans and adjacent seas. Marine Micropaleontology, 2, 121-200.
ANTARCTIC JOURNAL
