Australian Tertiary Paleotemperatures

Dorman, F. H.

doi:10.1086/627139

Cited by 73 publications

(22 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2). This isotopic event, which was evident in earlier curves for Australia (Dorman, 1966) and New Zealand (Devereux, 1967), was eventually correlated in open-marine drill sections around the globe, including Site 511 on the Falkland Plateau (Fig. 3).…”

Section: An Early Oligocene Antarctic Ice Sheet?supporting

confidence: 55%

Paleogene Glacial History of Antarctica in Light of Leg 120 Drilling Results

Wise¹,

Breza²,

Harwood³

et al. 1992

Proceedings of the Ocean Drilling Program

View full text Add to dashboard Cite

The Paleogene glacial history of Antarctica has been inferred largely from indirect evidence of glaciation gathered from the oceans beyond that remote, ice-shrouded, and inhospitable continent. This evidence includes the "proxy" stable isotopic record from the world's oceans; the occurrence of ice-rafted debris (IRD) in the Southern Ocean; inflections in sea-level curves; the presence of hiatuses in the deep-sea record; and changes in clay mineral assemblages, in the diversities of microfossil assemblages, and in the steepness of latitudinal biotic gradients. Ocean Drilling Program Leg 120 has added an important dimension to this growing body of evidence through the discovery of lowest Oligocene IRD at Site 748 on the Southern Kerguelen Plateau at a record distance north of the Antarctic continent (58°S latitude) and within a pelagic biosiliceous-carbonate ooze sequence that has yielded a complementary oxygen isotope record of the cryospheric event. We deduce that an ice sheet reached sea level during the earliest Oligocene (35.8-36.0 Ma) and that the effect was immediate and profound. In addition to the IRD, this event was manifested at Site 748 by a dramatic cooling of the surface waters surrounding the continent as indicated by a sharp increase in the percentage of cold-water calcareous nannoplankton, an increase in planktonic foraminiferal δ 18 θ values, and an increase in the percentage of biosiliceous material in the sediment. The temperature of the bottom waters over the plateau also decreased, and the volume of ice on the continent increased.We have reviewed the accumulated evidence from this and other investigations of the past two decades on and around Antarctica, and have concluded that ice sheets were present on the continent during the Oligocene, including the earliest Oligocene. Not necessarily permanent features, they probably went through many advances and contractions and may have disappeared completely at times. The rapid ice advance during the earliest Oligocene reached sea level at several widely scattered localities around the continent, but only for a brief period of time at some of these localities. Differences of opinion among investigators concern primarily the size and persistence of the Oligocene ice sheet(s).Tantalizing evidence of undated till deposits subjacent to well-dated Oligocene glaciomarine sequences along the Antarctic margin and possible occurrences of IRD beyond suggest the presence of glaciers during the late Eocene and possibly even during the early-middle Eocene. Included among the studies in this Scientific Results volume are new age calibrations from Eltanin piston cores taken at relatively low latitudes (38° to 58°S) in the southeast Pacific from which Eocene IRD has been reported. There is little agreement, however, among investigators as to whether an ice sheet was present at any time during the Eocene, particularly during early-middle Eocene times.

show abstract

Section: An Early Oligocene Antarctic Ice Sheet?supporting

confidence: 55%

Paleogene Glacial History of Antarctica in Light of Leg 120 Drilling Results

Wise¹,

Breza²,

Harwood³

et al. 1992

Proceedings of the Ocean Drilling Program

View full text Add to dashboard Cite

show abstract

“…The Coniacian-Santonian temperature maximum shows clearly in isotopic results from Western Europe (Lowenstam and Epstein, 1954; and is to some extent confirmed by results from Australia (Dorman, 1966) and New Zealand (Fig. 3, 4), but is not shown in the Russian results, based on both the oxygen isotope method and the Ca/Mg method (Naidin et at., 1966;Teis and Naidin, 1969;Berlin and Khabakov, 1967).…”

Section: World Variationsmentioning

confidence: 52%

“…Australian curve has been compiled from results in Dorman andGill (1959), lowenstam andEpstein (1954), Bowen (1961b), and Dorman (1968) and is only accurate for the intervals CenomanianAptian, Kimmeridgian and Bajocian. The age of belemnites obtained from the Kuabgen…”

mentioning

confidence: 99%

Oxygen isotope studies on Jurassic and Cretaceous belemnites from New Zealand and their biogeographic significance

Stevens

Clayton

1971

New Zealand Journal of Geology and Geophysics

126

View full text Add to dashboard Cite

<' I (0 18 ) and <' I (C13) results and isotopic temperatures are presented for transverse sections of New Zealand belemnites (Belemnopsis, Hibolithes, Dimitobelus) obtained from Jurassic strata correlated with Bajocian-Bathovian, Callovian, Kimmeridgian and Lower Tithonian, and Cretaceous strata correlated with Albian-Maastrichtian. Growth layer analyses also were carried out on 15 Jurassic and Cretaceous belemnites.Many of the belemnite specimens were found to be chemically altered to varying degrees, but growth analyses showed that the high isotopic temperatures which alter· ation is expected to produce were confined to two areas: surrounding the apical line and adjacent to the periphery of the specimen. Between these two areas there are generally plausible isotopic temperatures, and there is no reason to suspect that the temperature record has not been preserved there in its original form. Three or four major growth stages may be recognised in New Zealand belemnite guards and growth layer analyses suggest that these are annual; if this is so then in this respect the belemnites match the modern squids in having a three· or four.year life cycle. Variations in isotopic temperature of the be1mnites are comparable with those experienced seasonally by modern squids. Isotopic temperatures for the Jurassic and Cretaceous of New Zealand can be compared with sea water surface temperatures around the present day New Zealand coasts (36 0 _46 0 S. Lat.)' and inferred temperatures, based on these comparisons, are as follows: Upper Jurassic -temperatures slightly cooler than those of the present day; Albian and Cenomanian -temperatures slightly warmer; Turonian-?Coniacian -temperatures markedly warmer; Santonian-Maastrichtian -tem· peratures slightly warmer in the Santonian, but more so in the Campanian and Upper Maastrichtian. The New Zealand oxygen isotope results indicate a probable mid· latitude position, in the warm·temperate climatic zone, for New Zealand in the Jurassic and Cretaceous. New Zealand oxygen isotope results are compared with those obtained from overseas.

show abstract

“…The curve, besides showing a progressive cooling throughout the Cenozoic, reveals a significant fall in temperature during the Oligocene. Dorman (1966) produced a paleotemperature curve for Australia that is similar to the one of Devereaux from oxygen isotopes and Hornibrook (1966) presented evidence for mid-Tertiary cooling in Australia on biologic evidence. Bramlette (1955) postulated a temperature change in Barbados during the Oligocene from the distribution of four groups of microfossils.…”

Section: Paleoenvlronmental Implicationsmentioning

confidence: 92%

Radiation of Cenozoic Planktonic Foraminifera

Cifelli

1969

Systematic Zoology

168

View full text Add to dashboard Cite

The general aspects of planktonic foraminiferal radiation during the Cenozoic are shown by the distributional patterns of several morphotypic groups. There were two major radiations, one occurring during the Paleogene, the other during the Neogene. The radiations followed severe reductions in diversity which occurred at the close of the Cretaceous and again during the mid-Tertiary. Distributional patterns are iterative, and the Neogene radiation is essentially a repetition of what occurred during the Paleogene. According to the present interpretation, the ilerative patterns reflect major changes in the dynamic structure of surface waters. By analogy with the distribution of the modern fauna, it is suggested that thermal barriers were degraded during times of reduction and the oceans were uniformly cool. During the radiations thermal gradients were restored and the structure of the surface waters was essentially as it is today.

show abstract

Australian Tertiary Paleotemperatures

Cited by 73 publications

References 18 publications

Paleogene Glacial History of Antarctica in Light of Leg 120 Drilling Results

Paleogene Glacial History of Antarctica in Light of Leg 120 Drilling Results

Oxygen isotope studies on Jurassic and Cretaceous belemnites from New Zealand and their biogeographic significance

Radiation of Cenozoic Planktonic Foraminifera

Contact Info

Product

Resources

About