Stable isotope and minor element proxies for Eocene climate of Seymour Island, Antarctica

Abstract

Abundant and well‐preserved marine macrofossils on Seymour Island, Antarctica, provide a valuable resource to establish paleoenvironmental conditions at high southern latitudes during the warm Paleogene. Stable isotope, minor element, and 87Sr/86Sr compositions have been measured for the aragonite bivalve Cucullaea from the Eocene La Meseta Formation. The 87Sr/86Sr stratigraphy suggests an early to late Eocene age for the La Meseta Formation. Sea surface temperature estimates based on δ18O values range from 14.5° to 15.5°C in the early and middle Eocene to 10.5°C in the late Eocene. High‐resolution sampling along growth structures provides estimates of seasonality in temperature, which decrease considerably up section. To address the relative contribution of temperature and ice volume or salinity to the δ18O record, Sr/Ca was measured and evaluated as a potential independent paleothermometer for Cucullaea.

The Basal Penguin (Aves: Sphenisciformes) Perudyptes devriesi and a Phylogenetic Evaluation of the Penguin Fossil Record

“…However, extinction and artifact cannot be distinguished based on currently available data. Most late Eocene penguin species are from the La Meseta Formation of Seymour Island, which extends only to the latest Eocene before ending at an unconformity below the contact with the overlying latest Pliocene-Pleistocene Weddell Formation (Marenssi et al, 1998;Dutton et al, 2002;Gadzicki et al, 2004;MacPhee, 2005). Shallow marine strata from the EocenePliocene of Antarctica have not been extensively sampled due to inaccessibility.…”

100 Million Years of Antarctic Climate Evolution: Evidence from Fossil Plants

“…New paleoclimate data have also been derived from new collections of fossil angiosperm leaves from the Nordenskjold flora in the Cross Valley Formation of Late Paleocene age (Elliot and Trautman, 1982) and from the Middle Eocene Cucullaea 1 flora (Telm 5 of Sadler [1988], Cucullaea 1 allomember of Marenssi et al [1998], dated as 47-44 Ma by Dutton et al [2002]). In the Late Paleocene flora 36 angiosperm leaf morphotypes were identified, along with two pteridophytes (ferns), and podocarp and araucarian conifers.…”

“…CLAMP results are given below. A MAT of 13.5 ± 0.7°C was determined for the of 8-13.2°C (Pirrie et al, 1998) and 10.5-19.6°C (Dutton et al, 2002).…”

Fossil clitellate annelid cocoons and their microbiological inclusions from the Eocene of Seymour Island, Antarctica

“…Stilwell and Zinsmeister (1992) suggested a late Eocene age based on a biostratigraphic assessment of struthiolariid gastropods. Strontium isotope ratios ( 87 Sr/ 86 Sr) from bivalve shells were used by Dutton et al (2002) to argue for a middle Eocene age (44.5 or 47.4 Ma). However, more resolved strontium data of Ivany et al (2008) Sapo assemblage, whose age is well constrained by radiometric dates.…”