We have conducted radiocarbon (14C) dating of Japanese tree rings from 1053 to 921 BCE and 41 BCE to 130 CE. Dating was also performed using oxygen isotope dendrochronology to investigate subtle structures of the calibration curve corresponding to the beginning and the end of the Yayoi period in Japan. These two results followed IntCal20, which included the 14C ages of two Japan-sourced trees. The findings suggest that dating of specimens obtained from areas around the Japanese archipelago may be affected by periodic monsoons from the ocean, an effect that needs further examination.

The recently formed Batagay mega-thaw slump exposes permafrost deposits to a depth of up to 92 m below ground surface and provides insight into the climate record in the region of the most severe continental climate in the Northern Hemisphere. Radiocarbon and stable isotope data were obtained to verify the age of ice wedges in the Batagay yedoma (upper Ice Complex in the local cryostratigraphy), and to deduce paleoclimate information. A millennial-scale resolution paleotemperature record from radiocarbon-dated ice wedges spans Marine Isotope Stages (MIS) 3–2. The Batagay mean January air paleo-temperature during the 44.9–42 and 30.8–27.1 cal ka BP periods was stable cold has been reconstructed to about –51 ± 3°C each.

Yedoma sediments with thick syngenetic ice wedges have been studied on the Yamal Peninsula, northwestern Siberia. The accumulation of yedoma strata occurred under alternating subaqueous-subaerial conditions, and three tiers of ice wedge were formed mainly on subaerial stages. The ice wedges and enclosing sediments were dated, revealing that the ice wedges were formed between 29 and 18 cal ka BP, while the enclosing sediments are generally older, possibly due to contamination with ancient material (especially in the central part of the yedoma). However, the termination of yedoma complex formation was dated not later than 13.5 cal ka BP. Stable oxygen-isotope data for the ice wedges indicate more severe winter climate conditions during 25–21 cal ka BP, when mean January air temperatures were at least 10°C lower that modern ones, favoring syngenetic ice wedge growth. Yedoma accumulation in the western part of northern Siberia does not support the existence here of an ice sheet during the LGM.

The Suyanggae archeological complex is located in Aegok-li, Danyang County, Chungbuk Province, Korea (128°20'00"E, 365˚7'15"N, elevation 132 m). We investigated two Suyanggae Paleolithic localities (1 and 6). A total of 31 samples (18 localities) were analyzed for radiocarbon (14C) ages in three paleolithic cultural horizons of Suyanggae Locality 6 (SYG-6). The purpose of this paper is to report all dating results of SYG-6. It was found that ranges of 14C ages (BP) of cultural layers of SYG-6 are known to be 17,550 ± 80 ∼ 20,470 ± 70, 30,360 ± 350 ∼ 44,100 ± 1900, and 34,870 ± 540 ∼ 46,360 ± 510 BP for cultural layers 2, 3, and 4, respectively. We compared these age data with those of the previous study associated with Gunang Cave near Suyanggae Locality 1 (SYG-1). Based on the chronological information of the three archaeological sites, early humans lived in a rather cold environment from approximately 30,000 to 46,000 BP and disappeared between 30,000 ∼ 20,000 BP and then settled again in SYG-6 site during LGM period. This study demonstrates that archaeological study is important not only for understanding human occupations with their cultural development but also establishing climatic signals to which they have been adapted as a part of the human evolutional process.

A partial skeleton of the extinct ground sloth, Megalonyx jeffersonii, recovered from a farm near Millersburg, Ohio in 1890, was radiocarbon dated for the first time. The ungual dated is part of a skeleton mounted for exhibit at the Orton Geological Museum at Ohio State University and was the first mounted skeleton of this animal. From its initial discovery the bones were treated with multiple organic compounds that had the potential to compromise the radiocarbon age and the specimen required special treatments in order to obtain a valid radiocarbon age. The 14C measurement on the ungual from this skeleton (11,235 ± 40 14C yr BP = 13,180–13,034 cal yr BP) is the youngest 14C age presently determined for M. jeffersonii.

Lake Vanda, a perennially ice-covered Antarctic lake has a highly stratified structure with a pronounced density gradient from 45 m and is anoxic from 68 m down. In order to gain a greater understanding of the carbon cycling in the lake we attempted to measure sulphate reduction in the summer of 1994, but rates were below detectable limits of 1.2 × 106 mol sulphate yr−1. Therefore sulphate reduction was estimated by calculating the rate of sulphide diffusion from the anoxic zone. Sulphate reduction rates were estimated to be 17.7 × 103 mol sulphate yr−1, accounting for 30% of planktonic primary production over the whole lake, but over 100% of primary productivity in the deep chlorophyll maximum. Radiocarbon dating of organic matter in the sediment (565 ± 50 yr bp), suggests that little new organic carbon reaches the sediment from the upper water column. Oxygen diffusion into the anoxic zone could account for only 44% of sulphide reoxidation; therefore, alternative oxidizing potential presumably accounted for the remainder. Sulphate concentration may be controlled by the solubility limit for a mineral phase, perhaps gypsum, as it shows a positive correlation with conductivity. The sulphur species in the anoxic zone are highly enriched in 34S (sulphate δ34S = + 42 to + 46%0, sulphide δ34S = + 13.9%0) which may be explained by either selective removal of sulphide at the oxic/anoxic interface by precipitation of metal sulphides or previous loss ofH2S to the atmosphere. While sulphate reduction is an important part of the carbon cycle within the lake, the oligotrophic nature of Lake Vanda means that all microbiological process rates are very low. The data presented suggest a dynamic and complex history for Lake Vanda and are entirely consistent with present theories of the lake's history.