Antarctic marine temperatures: Late Campanian through Early Paleocene

Abstract

An oxygen isotope paleotemperature study of benthic foraminifera from the upper Campanian through lower Paleocene section at Seymour Island, near the coast of Antarctica, was done in conjunction with careful scanning electron microscope observations to monitor the state of foraminiferal preservation. The isotopic compositions of those samples which were deemed to be well preserved were the basis of the conclusion that Campanian through Paleocene high‐latitude shelf waters near Antarctica had temperatures between approximately 4.5° and 10.5°C. Temperatures during early and middle Maastrichtian time were slightly higher than those of either the late Campanian or late Maastrichtian. The inference of temperate climatic conditions in Antarctica is in agreement with paleoclimatic conclusions drawn on the species composition of the planktonic foraminiferal assemblages and the character of the planktonic foraminifera, as well as with published conclusions based upon paleobotanical evidence. The Maastrichtian and Campanian water temperatures at Seymour Island are similar to those inferred from published isotope ratios of Pacific Late Cretaceous benthic foraminifera from low latitudes, indicating that Campanian through early Paleocene deep ocean waters, at least in the Pacific and perhaps elsewhere as well, could have formed by sinking of surface waters in polar regions.

Latest Cretaceous to Cenozoic Climate and Oceanographic Developments in the Weddell Sea, Antarctica: an Ocean-Drilling Perspective

“…Leg 113 data provide no evidence of cryospheric activity in the Ant arctic region. A general increase of ~0.75%o-1.2%o in 5 18 0 val ues in foraminifers during the Maestrichtian indicates a cooling trend in both surface and intermediate waters (Barrera and Huber, this volume) and is similar to that reported for the Maes trichtian of Seymour Island, Antarctica (Barrera et al, 1987). Both sequences also exhibit a rapid increase in 5 18 0 near the be ginning of the late Maestrichtian ( -69.9 Ma) preceded by a dis tinct decrease in 5 13 C. In the absence of sea-ice during the Maes trichtian, it is unclear if the Antarctic represented a major source of deep waters to the world ocean.…”

“…Both sequences also exhibit a rapid increase in 5 18 0 near the be ginning of the late Maestrichtian ( -69.9 Ma) preceded by a dis tinct decrease in 5 13 C. In the absence of sea-ice during the Maes trichtian, it is unclear if the Antarctic represented a major source of deep waters to the world ocean. The interpretation of the sta ble isotopic composition of Maestrichtian foraminifers in the two Maud Rise sites led Barrera and Huber (this volume) to sug gest that deep waters of the South Atlantic were of Antarctic or igin, as Barrera et al (1987) had previously inferred based on studies of an Upper Cretaceous sequence on Seymour Island. The benthic foraminiferal oxygen isotopic data from Maud Rise, however, are unclear because cooler isotopic temperatures are recorded at the shallow (Site 689), rather than the deeper site (Site 690).…”

A multi-proxy approach to determine Antarctic terrestrial palaeoclimate during the Late Cretaceous and Early Tertiary

“…In the Antarctic Peninsula region oxygen isotope analyses of Early Cretaceous marine macrofossils and foraminifera (Barrera et al, 1987;Pirrie and Marshall, 1990;Ditchfield et al, 1994;Dutton et al, 2002) provide information on marine water temperatures (Fig. 5).…”

“…Conversely the greatest incidence of Table 3. (B) Marine temperature curve calculated from data given in Barrera et al (1987), Ditchfield et al (1994), Pirrie and Marshall (1990) recalibrated to the recent stratigraphic interpretations and calibrations using high precision Sr ages (Crame et al, 2004). Ditchfield et al (1994) calculated average temperatures for individual formations in this study we selected samples that now have good stratigraphic control and recalculated average temperatures from this data.…”

Paleoceanography of Upper Maestrichtian to Eocene Benthic Foraminiferal Assemblages at Sites 752, 753, and 754, Eastern Indian Ocean

“…9), which suggests that changes of bottom-water character caused faunal change. Although the deepwater source in the eastern Indian Ocean is not determinable at this site alone, Stott and Kennett (1989) indicated that the Antarctic may not have been a significant source of deep water during the early Paleocene, contrary to Barrera et al (1987) and Miller et al (1987). Stott et al (1990) also suggested that sea-surface temperatures of the oceans surrounding Antarctica were temperate during much of the Paleocene and Eocene.…”