columna estratigrafica
Post on 23-Dec-2015
245 Views
Preview:
DESCRIPTION
TRANSCRIPT
50
-50
-100
100
150
200
250
300
350
s vf fm c vcc
Sobr
al Fo
rmat
ion
Lópe
z de B
erto
dano
Fm.
0
50
100
Cros
s Vall
ey Fm
.
150
200
Height (m)
Formatio
n
P A
L E
O C
E N
EC
R E
T A
C E
O U
S0
Lithology
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70La
te
Late
M
iddl
eEa
rly
Maa
stric
htia
nTh
anet
Iian
Dan
ian
Sela
ndia
n
Age is uncertain. Early Late Paleocene age for at least part of the formation is based on dinocyst flora, chiefly co-occurence of Cerodinium [as Deflandrea] speciosa, Eisenackia [as Alisocysta] circumtabulata and Palaeoperidinium pyrophorum (Wrenn and Hart, 1988). Carbon isotope data (Fig. 2 of main paper) does not support recovery of the PETM.
Cretaceous-Paleogene boundary well defined on the basis of Ir-anomaly (Elliot et al., 1994). Age of oldest sediments in section is late Maastrich-tian based on palynological evidence (Bowman et al., 2012, 2013) Magneto-stratigraphic constraints (Tobin et al., 2012) indicate that the lowest sample analysed (133.5 m below K-Pg boundary) is in the upper part of chron C30N, and thus likely to be no older than ~67 Ma (Gradstein et al., 2012).
Base of Sobral Formation approximately coeval with the highest abundance of Trithyrodinium evittii and is early Danian in age (Bowman et al., 2012). Palyno-logical work by Askin (1988) indicates that the formation is predominantly Danian, though putative evidence for a hiatus near the top of the succession may mean that the uppermost strata is Late Paleocene, and hence younger than Danian.
Figure DR1. Summary diagram highlighting available age control through the studied Seymour Island succession. References cited:
Askin, R. A., 1988, Campanian to Paleocene palynological succession of Seymour and adjacent islands, northeastern Antarctic Peninsula, in Feldmann, R. M. and Woodburne, M. O., eds., Geology and Paleontology of Seymour Island, Antarctic Peninsula: Boulder, Colorado, Memoir, Geological Society of America 169, p. 131–153.Bowman, V. C., Francis, J. E., Riding, J. B., Hunter, S. J., and Haywood, A. M., 2012, A latest Cretaceous to earliest Paleogene dinoflagellate cyst zonation from Antarctica, and implications for phytoprovincialism in the high southern latitudes, Review of Paleobotany and Palynology, v. 171, p. 40-56.Bowman, V. C., Francis, J. E., Riding, J. B., 2013, Late Cretaceous winter sea ice in Antarctica?: Geology, v. 41, p. 1227-1230.Elliot, D. H., Askin, R. A., Kyte, F. T., and Zinsmeister, W. J., 1994, Iridium and dinocysts at the Cretaceous-Tertiary boundary on Seymour Island, Antarctica: Implications for the K-T event: Geology, v. 22, p. 675-678.Gradstein, F.M., Ogg., Schmitz, M.D., and Ogg, G.M., 2012, The Geologic Time scale 2012: Amsterdam, Elsevier, 1143 pp.Tobin, T. S., Ward, P. D., Steig, E. J., Olivero, E. B., Hilburn, I. A., Mitchell, R. N., Diamond, M. R., Raub, T. D., and Kirschvink, J. L., 2012, Extinction patterns, δ18O trends, and magnetostratigraphy from a southern high-latitude Cretaceous-Paleogene section: Links with Deccan volcanism: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 350-352, p.180-188.Wrenn, J. H., and Hart, G. F., 1988, Paleogene dinoflagellate cyst biostratigraphy of Seymour Island, Antarctica, in Feldmann, R. M. and Woodburne, M. O., eds., Geology and Paleontology of Seymour Island, Antarctic Peninsula: Boulder, Colorado, Memoir, Geological Society of America 169, p. 321–447.
Timescale (Gradstein et al. 2012)
(Ma)
Grainsize
GSA DATA REPOSITORY 2014205Data repository item for Kemp et al. (2014): A cool temperate climate on the Antarctic Peninsula through the latest Cretaceous to early Paleogene
Table DR1. Geochemical data and calculated soil pH and soil paleotemperature used in figure 2 of main paper. Full details of MBT’, CBT, pH and paleotemperature calculations can be found in the references listed (Peterse, F. et al., 2012, Geochimica et Cosmochimicha Acta, v. 96, p. 215-‐229; Weijers, J. W. H., et al., 2007, Geochimica et Cosmochimica Acta, v. 71, p. 703-‐711.). See also main text.
top related