A reexamination of the sequences of planktonic foraminifers and calcareous nannoplankton in the Plio-Pleistocene sediments beneath the Louisiana continental shelf has been undertaken in order to modernize correlation schemes that were established 10–20 y.a. As a consequence, it can be shown that (1) a new correlation of marine micropaleontological and continental glacial events is necessary; (2) the Gulf Coast faunal events can be reliably correlated with those in the type Italian Pleistocene section and in the deep-sea cores; (3) it is becoming increasingly evident that it is invalid to correlate the Plio-Pleistocene boundary, as defined by paleontology, with a climatically defined boundary.

Presently submerged Bahaman stalagmites can be used to date Pleistocene low sea level stands. Good precision was obtained using both 14C and 230Th-/234U-methods. The respective dates obtained were 21,900 ± 600 and 22,000 ± 350 YBP.

A suite of four terraces in the upper Rio Henares drainage system (Rio Tajo basin) now provides a partial geomorphological link between the Middle Pleistocene, Lower Paleolithic archeological sites at Ambrona and Torralba (upper Ebro basin) and those in the vicinity of Madrid. The Campiña and Low Terrace features are shown by radiocarbon dating to be of Holocene and Würm ages, respectively, while the Middle and High Terraces are best designated as being Middle and Lower Pleistocene ages, respectively. Stratigraphic relationships between the upper and lower Rio Henares segments need to be established.

Four new radiocarbon dates of elevated strandlines in tectonically active areas of eastern Indonesia and East Malaysia indicate average rates of uplift that range between 4.5 and 9 mm annually during the past 24,000 yr. These values are at least three times higher than former estimates from eastern Indonesia. Another radiocarbon date from the south arm of Sulawesi—also tectonically mobile—indicates a rate of uplift of 1.4–2.5 mm per year which corresponds with earlier determinations. This particular case, however, suggests that the sample was probably located close to a north-south axis about which southern Sulawesi was tilted during the Quaternary.

In the Langkawi islands, West Malaysia, one of the regionally ubiquitous shorelines at about 2 m above sea level was dated at 2590 ± 100 yr BP which corresponds with Fairbridge's (1961) Abrolhos Submergence.

A series of radiocarbon determinations have been carried out of lacustrine deposits contained in three playa basins, namely at Sambhar, Didwana and Lunkaransar, in Rajasthan, in conjunction with stratigraphical and palynological investigations. It is revealed that the lake deposits, which overlie thick beds of sand at each site, date back from early Holocene times (ca. 10,000 B.P.).

The authors present the radiocarbon evidence together with an outline of the stratigraphy of the deposits, and attempt to reconstruct the sedimentary sequence in the three basins since the beginning of the lacustrine phase. The significance of the more or less synchronous development in all the three playa basins is discussed with reference to postglacial climatic oscillations in northwest India.

When the Wisconsin ice sheet stood at its maximum position, tundra vegetation bordered the ice sheet. In the eastern United States, tundra extended at least 300 km due south of the ice border at 2700 ft (800 m) elevation on the Allegheny plateau. Spruce and jack (and/or red) pine forest grew at lower elevations in Virginia. On the coastal plain, and farther south, in the piedmont of northern Georgia, jack pine dominated the forest vegetation over a large region.

As the ice sheet receded, the vegetation underwent a series of changes. Coniferous forest was replaced by deciduous forest, beginning 13,600 B.P. in Georgia. The frequency of white pine began to increase in Virginia at about the same time, and the frequencies of deciduous trees, about 1000 yr later. On the Allegheny plateau, no change took place in the tundra vegetation until 12,700 B.P., when tundra was replaced by open, spruce woodland. Jack and/or red pine grew mixed with, or nearby, the spruce. Pollen from deciduous trees (mainly oak, ash, and hornbeam) reached the site in greater quantity than before. Possibly the increase indicates a change in prevailing wind direction.

On the Allegheny plateau, 10,500 years ago, the boreal woodland was replaced by a mixed coniferus-deciduous forest which included white pine. At about the same time (or perhaps a thousand years later), a similar change occurred in Connecticut. At lower elevations in the Shenandoah Valley, spruce forests including white pine were replaced by oak and other hardwoods.

In the early Holocene, at a time we unfortunately were not able to pinpoint by radiocarbon dating, deciduous forest began to grow on the Allegheny plateau. Later there was a series of changes in the composition of the forest. High frequencies of oak pollen occur throughout the sequence, with successive maxima of hemlock, beech, and finally, hickory. High percentages of chestnut pollen occur with a maximum approximately coincident with the maximum of beech. These changes are probably significant both from stratigraphic and paleoecologic points of view, and should be studied in greater detail at sites where radiocarbon dating will be possible. The early maximum of chestnut pollen is a major difference between the pollen sequence in the Alleghenies and southern and central New England, suggesting that this species was very slow to move northward, arriving in New England just 2000 B.P. as the result of migration, not climatic change.

Redrock Lake is situated at 3,095 m in the subalpine zone on the east flank of the Front Range, Boulder County, Colorado. The lake lies on Pinedale moraine, and it contains 170 cm of organic sediments that overlie 10 cm of silty clay. The oldest of seven 14C dates from the organic sediment is 9,490 ± 150 yr B.P., a minimum estimate of the time since Middle Pinedale ice receded from the lake basin.

A percentage pollen diagram and an absolute pollen diagram providing pollen deposition rates in grains/cm2/14C yr are compared and contrasted. Possible measurement errors are considered in detail, and for the first time confidence limits are assigned to all pollen data. A means of converting 14C years to calendar years is presented, and its effect on the diagram's deposition rates is discussed.

The silty clay contains a peculiar Artemisia-dominated pollen assemblage with very low pollen influx rates, which suggests the lake was receiving large volumes of glacial meltwater during its early history. The overlying organic sediments are characterized by pollen deposition rates of 4,000–6,000 grains/cm2/yr. With fluctuations, deposition rates of Pinus and total anemophilous pollen increase upward in the core; this evidence for a general upward shift in the region's vegetation zones during Postglacial time is supported by pollen trends from modern surface samples.

A rhyolitic volcanic ash bed about 0.3 m thick is exposed in a roadcut along Texas Highway 193 near Mount Blanco in the upper part of a sequence of Pleistocene sedimentary deposits at the type locality of the Blanco Formation, about 59 km northeast of Lubbock, Texas. This ash, here named informally the Guaje ash bed, has chemical and petrographic characteristics closely resembling those of the rhyolitic air-fall tephra (Guaje Pumice Bed) that directly underlies ash flows of Pleistocene age in the Jemez Mountains of northern New Mexico. The Guaje Pumice Bed and the ash flows belong to the Otowi Member of the Bandelier Tuff. Properties common to the Guaje ash bed and the Guaje Pumice Bed include: refractive index of glass, 1.497–1.498; microphenocrysts of quartz, sanidine (Or42–44), ferrohedenbergite (Fe51Ca42Mg7), chevkinite, allanite, zircon, and magnetite. Chemical composition of the glass of the Guaje ash bed matches that of the Guaje Pumice Bed for all major elements except K and Na and for trace elements determined by standard chemical analyses, atomic absorption, and neutron activation. Paleomagnetic measurements indicate that the ash has reverse depositional remanent magnetization. Glass shards of the ash have a fission-track age of about 1.4 ± 0.2 m. y. Sanidine from the Guaje Pumice Bed and its genetically related ash-flow sheet in the Jemez Mountains was K-Ar dated at about 1.4 m. y. by R. R. Doell and his colleagues in 1968. Correlation of the Guaje ash bed with the radiometrically dated Guaje Pumice Bed establishes a minimum age of about 1.4 m. y. for the Blanco Formation.

Carbon-14 dates for fossil wood, peats, and organic soils from periglacial and glucial sites between 1100 and 2100 m in the Snowy Mountains area, southeastern Australia, are interpreted in relation to the site characteristics and the present climate. The dates indicate a widespread cold period commencing about 34,000-31,000 years ago, the effects of which apparently continued until about 15,000 and locally until about 9000 years ago; a subsequent warmer period; and a colder phase about 3000-1500 years ago. Mean annual temperatures during the first cold period are estimated to have been at least 8–10°C lower than at present, and at least 3°C lower during the cold phase of 3000-1500 years ago.