Word file (916 KB )

advertisement
Supplementary Information
Migration of a Late Cretaceous Fish
Scott J. Carpenter1†, J. Mark Erickson2, F.D. Holland, Jr.3
1
Paul H. Nelson Stable Isotope Laboratory, Department of Geoscience, Center for
Global and Regional Environmental Research, University of Iowa, Iowa City, IA 522421379, USA.
2
3
Geology Department, St. Lawrence University, Canton, NY 13617, USA.
Professor Emeritus, Department of Geology and Geological Engineering, University of
North Dakota, Grand Forks, ND 58202, USA.
†
To whom correspondence should be addressed: Department of Geoscience, Center for Global and
Regional Environmental Research, University of Iowa, Iowa City, IA 52242-1379, USA. e-mail: scott-jcarpenter@uiowa.edu
1
SUPPLEMENTARY INFORMATION
Figure 1:
UV Fluorescence photomicrographs of a portion (near kernel) of the unprepared inner
surface of two V. vulpes otoliths. There is an overall high level of organic matter
throughout the otoliths and a higher concentration along concentric growth bands.
Growth Curves for Vorhisia vulpes
The growth curves for the four V. vulpes otoliths are found in Fig. 2. These are
typical growth curves for an organism that has rapid juvenile growth and decreasing
growth rates with ontogeny. It appears that the death of these fish occurs prior to or
coincident with achieving their maximum size.
2
Distance from Kernel (in mm)
Vorhisia vulpes Growth Curves
10
10
9
9
8
8
7
7
6
6
5
5
4
4
3
3
Otolith #1
Otolith #2
Otoltih #3
Otolith #4
2
1
2
1
0
0
0
1
2
3
4
5
Age (in Years/Winters)
Figure 2:
Growth curves for V. vulpes otoliths #1-4. Age (in years/winters) is assigned on the basis
of 18O value maxima (winter temperature minima). The green shaded area represents
the estuarine phase of growth and the blue shaded area represents the marine phase of
growth.
Strontium Isotope Data
Specimens described here are from rocks within or above the Jeletzkytes nebrascensis
Zone as it is currently being applied in the region. However, it should be noted that
neither relative position of the Campanian-Maastrichtian boundary vis-à-vis Western
Interior ammonite zonation, nor absolute ages assignable to parts of the Maastrichtian in
the region, are as yet established with certainty or with general agreement among
workers1. The sediments from which V. vulpes was collected are Hell Creek equivalent occurring in incised channels within the Iron Lightning Member of the Fox Hills
Formation. On the basis of the floral zonation of the Linton Member and Hell Creek
Formation2, we conclude that the age of these materials is 65.8 to 66.0 Ma (near the
C29r-C30n boundary)3,4. This age assignment and our 87Sr/86Sr ratios of the marine phase
of V. vulpes are consistent with analyses of Western Interior marine fauna from the
3
underlying Hoploscaphites nicolletti Zone of the Fox Hills Formation (and older units)5
and of marine barite 6.
Marine 87Sr/86Sr ratios during the Latest Maastrichtian are not well constrained and
global correlations are not precise
point in the marine
where
87
6,7
. It is generally agreed that there is an inflection
87
Sr/86Sr ratio curve during the Late Maastrichtian-Early Paleocene
Sr/86Sr ratios reach a maximum value of near 0.70780 near the K-T boundary
(~65 Ma)
6, 8-10
. Our
87
Sr/86Sr ratios of 0.70778 to 0.70779 for the marine phase of V.
vulpes are consistent with an age between 67 and 65.5 Ma (Fig. 3).
Strontium isotope ratios of selected micro-samples of marine and estuarine phases
of V. vulpes otoliths suggest that the 87Sr/86Sr ratio of river water entering the Fox HillsHell Creek estuary is lower than that of ambient seawater (Table 1) 11. Like McArthur et
al. 5, we conclude that the river systems entering the Fox Hills-Hell Creek estuary have
both relatively low
87
Sr/86Sr ratios and [Sr], thereby yielding little change in marine
Sr/86Sr ratios with even significant degrees of mixing. As a result, the 18O values of
87
estuarine carbonates may be more sensitive indicators of the degree of freshwaterseawater mixing than their 87Sr/86Sr ratios. A detailed discussion of the mixing relations
in the Fox Hills-Hell Creek estuary during the Late Maastrichtian is described in
Carpenter et al. 11.
4
Western Interior Fauna
60
60
62
62
64
66
64
Tertiary
66
Cretaceous
68
70
68
Vorhisia vulpes
This Study
70
72
74
74
76
76
78
78
80
80
82
82
84
84
86
86
88
88
McArthur et al. (1994)
Western Interior Fauna
90
0.7072
90
0.7074
87
0.7076
Sr /
86
0.7078
0.7080
Sr
87
Sr/86Sr ratios ratios of Western Interior Seaway fauna during the late Cretaceous from
McArthur et al. 2 with marine V. vulpes data plotted at 65.9 Ma (V. vulpes data are
normalized to a 87Sr/86Sr ratio of 0.710248 for NBS-987 for direct comparison) 5. The
Cretaceous-Tertiary boundary is plotted at 65.5 Ma.
Figure 3:
Table 1.
Age (in Ma)
72
87
Sr/86Sr ratios of marine and estuarine phases of V. vulpes.
Sample ID
Environment
18O (PDB)
V. vulpes #2.05
V. vulpes #2.07
V. vulpes #2.14
Estuarine
Estuarine
Marine
V. vulpes #1.04
V. vulpes #1.08
V. vulpes #1.22
V. vulpes #1.25
Estuarine
Estuarine
Marine
Marine ?
* 87Sr/86Sr
87
Sr/86Sr*
(±)
-7.0
-4.1
-1.5
0.707754
0.707761
0.707799
14
17
14
-6.5
-3.8
-0.9
-2.7
0.707738
0.707730
0.707784
0.707777
12
17
15
16
ratios are not normalized.
5
Mixing Relations in the Fox Hills-Hell Creek Estuary
18O values of the marine growth phase of V. vulpes are consistent with those of the
infaunal marine bivalves Cucullaea nebrascensis, Cymbophora warrenana, Protocardia
subquadrata and the gastropod Drepanochilus evansi of the Timber Lake Member of the
Fox Hills Formation reported by Carpenter et al.11,12 (from –2 to 0 ‰). Preliminary
micro-sampling of the marine bivalve Tancredia americana (Timber Lake Member) from
two years of shell growth yields a range of 18O values from –2.6 to 0.03 ‰ (mean = –
1.4 ‰) and 13C values from –0.4 to 1.1 ‰ (mean = 0.4 ‰) 11. These values confirm the
overall marine isotope ratios and the seasonal temperature variation observed in the
marine phase of V. vulpes discussed here (Fig. 4).
Specimens of the bivalve Corbicula sp. and the gastropod Euspira subcrassa
occurring with V. vulpes otoliths have markedly different 18O values (-20.4 to –12.7 ‰
and –2.8 to –0.5 ‰, respectively) 11 (Fig. 4). The high 18O values of E. subcrassa are
comparable with the marine phases of V. vulpes and other marine mollusks from the Fox
Hills Formation
12
. Exceptionally low 18O values of Corbicula sp. are consistent with
those of Late Maastrichtian freshwater bivalves (unionids) from the Western Interior 11,13.
Dettman and Lohmann
13
concluded that the oxygen isotope ratios of rivers of the Late
Mesozoic and Early Cenozoic of west-central North America (e.g., the Hell Creek fluvial
system) were dominated by high-altitude precipitation or snow/ice meltwater. Data from
Corbicula sp. suggest that waters sourced at high-elevation in the Laramide Orogen
flowed eastward with minimal dilution and mixed with the Western Interior Seaway in
the central Dakotas 11.
The low 18O values of Corbicula and unionids
11,13
represent riverine conditions
upstream from the estuarine locations where V. vulpes lived as a juvenile and that
6
Corbicula shell fragments were transported downstream into the Fox Hills-Hell Creek
estuary where V. vulpes had returned to spawn. As one specimen of V. vulpes is abraded
(SLU FR476 - specimen #3), some post-mortem transport may have occurred in the tidal
channel or perhaps it was abraded in place on a wave-washed shore along the estuary.
There is no evidence to suggest that V. vulpes lived for an extended period of time, in the
isotopically distinct freshwaters of the Hell Creek delta platform in which Corbicula sp.
and unionids grew.
Juxtaposition of specimens with such a wide range of 18O values requires a diverse
and dynamic system where specimens representative of several habitats can be readily
mixed in facies that were either brackish or marine
14
. Presence of significant storm
deposits in the top of the barrier bar facies implies frequent wash-over transport and
deposition of marine bioclasts into back-barrier estuary settings
15,16
. Furthermore, V.
vulpes is not found among the fully marine faunas of the Fox Hills Formation. Although
it is remotely possible that V. vulpes otoliths were transported from a marine
environment, concentrations of well-preserved otoliths of a similar age class in channel
lag deposits more likely indicates these V. vulpes migrated back to their natal waters to
spawn and die. Such an interpretation is consistent with the migratory behavior of
modern fishes and is constrained by the 18O and 13C values of various biogenic
carbonates from the Fox Hills-Hell Creek estuary 11.
18O and 13C values of marine, estuarine, and freshwater biogenic carbonates from
the Fox Hills and Hell Creek Formations produce a linear mixing trend interpreted as the
mixing of Fox Hills seawater and Hell Creek river water over a range of ~20 ‰ for 18O
values and ~7 ‰ for 13C values
11
. If we assume that marine mollusks and marine
phases of V. vulpes were precipitated from seawater with a 18O value of –1 ‰ SMOW 17
7
and that unionids and Corbicula sp. were precipitated from freshwater of –20 ‰
SMOW13, the lowest 18O values of the juvenile growth phases of the V. vulpes (–7.0, 6.5, -5.7, -4.2 ‰ (PDB)) indicate that these fish grew in waters composed of 68 to 83 %
seawater (using a simple two endmember mixing model). Our data indicate that V.
vulpes did not live in freshwater as suggested by Waage
18
and Frizzell
19
, but instead
preferred shallow marine waters for much of its adult life and spawned in brackish
waters.
Figure 4:
18O and 13C values of V. vulpes otoliths plotted relative to data from marine, estuarine, and
riverine mollusks from the late Cretaceous of North and South Dakota. The estuarine portions
of V. vulpes represent a mixture of 68 to 83 % seawater. A linear mixing trend of this sort
requires that [HCO3-] is similar in both seawater and river water. Specimens from the
estuarine Iron Lightning Mbr. of the Fox Hills Fm., include: Vorhisia vulpes, Euspira
subscrassa, and Corbicula sp. collected in the 1960s from the Colgate Lithofacies, Fox Hills
Fm., Iron Lightning Badlands (Type Locality for Iron Lightning Mbr.), Redelm NE
Quadrangle, Ziebach Co., South Dakota. Unionids and Crassostrea sp. from the basal Hell
Creek Fm. are from the Yale Peabody Museum Division of Invertebrate Paleontology
(YPMIP A4716, YPMIP A688, respectively, Iron Lightning, Ziebach Co., South Dakota).
8
References Cited
1.
Erickson, J.M. The Dakota Isthmus -- closing the Late Cretaceous Western Interior Seaway. North
Dakota Academy of Science Proceedings 53, 124-129 (1999).
2.
Peppe, D.J. and Erickson, J.M. Fox Hills I, a new Late Maastrichtian megafloral zone from the
Missouri Valley Region, demonstrating eastward diachroneity of the Hell Creek Formation in North
Dakota. Geological Society of America Abstracts with Program, 34, 429-430 (2002).
3.
Hicks, J.F., Johnson, K.R., Obradovich, J.D., Tauxe, L., and Clark, D. Magnetostratigraphy and
geochronology of the Hell Creek and basal Fort Union Formations of southwestern North Dakota and a
recalibration of the age of the Cretaceous-Tertiary boundary. In: Hartman, J.H., Johnson, K.R., and
Nichols, D.J. (eds.) The Geological Society of America Special Publication #361, 35-55 (2002).
4.
Wilf, P., Johnson, K.R., and Huber, B.T. Correlated terrestrial and marine evidence for global climate
changes before the mass extinction at the Cretaceous-Paleogene boundary.
Proceedings of the
National Academy of Sciences, 100, 599-604 (2003).
5.
McArthur, J.M., Kennedy, W.J., Chen, M., Thirlwall, M.F. & Gale, A.S.
Strontium isotope
stratigraphy for Late Cretaceous time: direct numerical calibration of the Sr isotope curve based on the
US Western Interior. Palaeogeography, Palaeoclimatology, Palaeoecology 108, 95-119 (1994).
6.
Mearon, S, Paytan, A., and Bralower, T.J. Cretaceous strontium isotope stratigraphy using marine
barite, Geology 31,15-18.
7.
Barrera, E. & Savin, S. Evolution of late Campanian-Maastrichtian marine climates and oceans. in:
Barrera, E. and Johnson, C.C. (eds.) Evolution of the Cretaceous ocean-climate system, Special Paper
#332, Geological Society of America, 245-282 (1999).
8.
Koepnick, R.B., Burke, W.H., Denison, R.E., Hetherington, E.A., Nelson, H.F., Otto, J.B. & Waite,
L.E. Construction of the seawater
87
Sr/86Sr curve for the Cenozoic and Cretaceous: supporting data.
Chemical Geology (Isotope Geoscience Section) 58, 55-81 (1985).
9.
Jones, D.S., Mueller, P.A., Bryan, J.R., Dobson, J.P., Channell, J.E.T., Zachos, J.C. & Arthur, M.A.
Biotic, geochemical, and paleomagnetic changes across the Cretaceous/Tertiary boundary at Braggs,
Alabama. Geology 15, 311-315 (1987).
10. Denison, R.E., Koepnick, R.B., Fletcher, A., Dahl, D.A. & Baker, M.C.
Reevaluation of Early
Oligocene, Eocene, and Paleocene seawater strontium isotope ratios using outcrop samples from the
U.S. Gulf Coast. Paleoceanography 8, 101-126 (1993).
9
11. Carpenter, S.J., Erickson, J.M. & Hoganson, J.W. Isotopic characterization of the Late Cretaceous Fox
Hills-Hell Creek Estuary of North and South Dakota. Geological Society of America Abstracts with
Program, (2002).
12. Carpenter, S.J., Erickson, J.M., Lohmann, K.C & Owen, M.R. Diagenesis of fossiliferous concretions
from the Upper Cretaceous Fox Hills Formation, North Dakota. Jour. Sed. Petrology 58, 706-723
(1988).
13. Dettman, D.L. & Lohmann, K.C Oxygen isotope evidence for high-altitude snow in the Laramide
Rocky Mountains of North America during the Late Cretaceous and Paleogene. Geology 28, 243-246
(2000).
14. Erickson, J.M. Subsurface stratigraphy, lithofacies and paleoenvironments of the Fox Hills Formation
(Maastrichtian: Late Cretaceous) adjacent to the type area, North Dakota and South Dakota – toward a
more holistic view. in: Erickson, J.M. and Hoganson, J.W. (eds.), Proceedings of the F. D. Holland,
Jr., Geological Symposium. North Dakota Geological Survey Miscellaneous Series 76, 199-241
(1992).
15. Erickson, J.M.
Revision of the Gastropoda of the Fox Hills Formation, Upper Cretaceous
(Maestrichtian) of North Dakota. Bulletins of American Paleontology 66, 127-253 (1974).
16. Bailey, L.T. & Erickson, J.M. Preferred orientation of bivalve shells in the upper Timber Lake
Member, Fox Hills Formation in North Dakota--preliminary interpretations. The Compass of Sigma
Gamma Epsilon 50, 23-37 (1973).
17. Shackleton, N.J. & Kennett, J.P. Paleotemperature history of the Cenozoic and initiation of Antarctic
glaciation: oxygen and carbon isotope analyses in Deep Sea Drilling Project Sites 277, 279, and 281.
in: Kennett, J.P., Houtz, R.E., et al., Initial reports of the Deep Sea Drilling Project, v. 74, Washington,
D.C., U.S. Government Printing Office, 761-776 (1975).
18. Waage, K.M. The type Fox Hills Formation, Cretaceous (Maestrichtian), South Dakota, Part 1.
Stratigraphy and Paleoenvironments. Peabody Museum of Natural History, Yale University, Bulletin
27, 171 pgs., (1968).
19. Frizzell, D.L. Otoliths of new fish (Vorhisia vulpes, N. Gen., N. Sp. Siluroidei?) from Upper
Cretaceous of South Dakota. Copeia 2,178-181 (1965).
10
Download