The Turkana, Nakuru-Elmenteita, and Naivasha basins in the Rift Valley of East Africa experienced high water levels during the period of 10,000–7000 yr B.P. Analyses of the modern hydrologic and energy budgets for these basins, along with that of Lake Victoria, were used to infer the amount of precipitation that would have been required to maintain the enlarged paleolakes of the early Holocene. Precipitation must have been at least 150–300 mm/yr (15 to 35%) above the modern average. The precipitation estimates were fairly consistent among the various basins, but no quantitative estimate was made for the additional precipitation required to account for overflow from the Rift Valley lake basins. Discharge from the Lake Victoria basin around 1880 A.D. was considerably above the more recent average, and the increased discharge into the White Nile for that period might have been similar to that of the early Holocene. A sensitivity analysis showed that temperature changes were probably not too important for changing the hydrologic-energy budget; changes of albedo, Bowen ratio, and cloudiness were likely to have been of greater importance.

The Konya Basin, a closed depression at the southern margin of the Anatolian Plateau, contained a shallow but extensive lake during the late Quaternary. Nearshore sands and gravels containing Dreissena shells form prominent depositional terraces around the basin edges at elevations between 1005 and 1020 m, and the highest has been dated at more than 30,000 yr B.P. The last major phase of limnic sedimentation occurred between 23,000 and 17,000 yr B.P., after which the lake fragmented into a number of subbasins or secondary depressions which evolved to become either marshes or playas. A final expansion of these residual lakes has been dated to ca. 11,000 yr B.P. in one secondary depression. Archaeological and other evidence indicate that only minor lake-level fluctuations occurred during the Holocene. The dominant sedimentary process over the last 10,000 years has been alluviation at the basin margin. The Konya sequence confirms that the most recent period of high-lake levels in the northern Near East was of the last glacial age. The palaeolakes of Anatolia and Iran were, however, more a product of reduced evaporation brought about by temperature depression than of changes in precipitation, and thus belie their often-used description as an indicator of “pluvial” climatic conditions.

The Tarija Formation of southern Bolivia, which is well known for its classic vertebrate faunas, is of prime importance in understanding of the chronology of the Ensenadan Land Mammal Age. This formation consists of well-exposed and relatively fossiliferous sections of clays, clayey silts, sands, gravels, and tuffs which were deposited in a predominately fluviatile regime in a Pleistocene structural basin. Four stratigraphic sections, each measuring 110 m or less, were studied to establish a magnetic polarity stratigraphy. Paleomagnetic samples were collected from the finer-grained sediments at 100 sites spaced at stratigraphic intervals of 5 m or less. All paleomagnetic specimens were demagnetized in alternating fields of least 250 oersteds (oe). Some specimens were also thermally demagnetized at 200°C or more. Of the 100 sites, 77 were ultimately used to determine the magnetic polarity zonation. Based on the four sections sampled, the Tarija Formation spans a time interval from about 1 my to about 0.7 my B.P. or perhaps younger. The lower half of the composite section is of reversed polarity punctuated by a short normal event. This sequence probably represents the late Matuyama chron with the Jaramillo subchron. The upper part of the section is of normal polarity and represents early Brunhes time. A tuffaceous unit 43 m above the Brunhes-Matuyama boundary yielded a fission track (zircon) age of 0.7 ± 0.2 by B.P. These data indicate that the classic Tarija fauna is middle Pleistocene Ensendan in age.

New Zealand Quaternary marine and terrestrial sequences contain numerous tephras, or volcanic-ash horizons, that are the distal correlatives of voluminous welded ignimbrite sheets, erupted from central North Island. Electron microprobe analyses of glass shards from the distal tephras demonstrate their homogeneity and are shown to identify each tephra examined. By matching tephras from stratigraphically controlled sequences, the first comprehensive tephra stratigraphy spanning from 50,000 to 700,000 yr ago and covering the New Zealand region is advanced.

Analyses on glass shards from the unwelded base of ignimbrite sheets are comparable to the distal tephra analyses and allow correlation between ignimbrites and to the distal tephras. The better exposed tephra record constrains the number of separate eruptive events and the stratigraphy of the ignimbrites, both of which were previously confused by lack of outcrop.

Samples from pumiceous marine sediments were found to contain two or more chemically distinct populations of glass. The pumice is in cross-bedded sands or sand lenses within conglomerate, attesting to a shallow high-energy environment where reworking could occur. However, each glass population could be matched to older, known tephras.

The use of energy-dispersive X-ray fluorescence analysis (XES) for the routine identification of three tephras (Mazama, Bridge River, Mount St. Helens Yn) commonly found in archeological sites in British Columbia has been investigated. Researchers have often assumed that chemical analysis of bulk samples of glass separates would be hampered by contamination and weathering effects. Our results indicate that XES of bulk glass separates provides a very reliable method for rapidly identifying the three tephras in question, even with a very simple sample preparation. This should enable persons not skilled in geology or in tephrochronology to collect and to identify samples of these tephras. Finally, as a part of the study, similar measurements were made on the separated glass portions of these three tephras and of three others (Glacier Peak B and G, White River) from northwest North America. The results suggest that this method may provide tephrochronologists with a useful additional tool for studying tephras in other regions.

The Japanese Archipelago was almost entirely covered by coniferous forests during the last glacial maximum. Northern Hokkaido was distinguished by coniferous parkland and tundra vegetation, while southern Hokkaido and northernmost Honshu were covered by northern boreal coniferous forests consisting mainly of Picea jezoensis, Picea glehnii, Abies sachalinensis, and Larix gmelinii; Tsuga was missing from the forest. More diverse boreal forests including species from Sakhalin and northern Japan grew together in northeastern Honshu. Central Honshu and the mountains of southwestern Japan supported subalpine coniferous forests which are now mainly restricted in distribution to the central mountains. Temperate coniferous forests (Picea polita, Abies firma, and Tsuga sieboldii) existed principally in the modern mid-temperate and evergreen laurel-oak forest regions. Haploxylon pine and tree birch were also abundant in the boreal and cool-temperate zones, as was Diploxylon in the southern temperate zone. Significant populations of Fagus were found along the Pacific coasts of Kyushu and Shikoku, but they were too small to be defined as a beech forest zone. Quercetum mixtum (Quercus, Ulmus, and Tilia) was more common in the coastal lowlands of southwestern Japan than those of northeastern Honshu; it was completely eliminated from Hokkaido. The reduced mean August temperature inferred from the floral assemblages showed a latitudinal gradient 20,000 yr ago; it was 8–9°C in northern Hokkaido, 7.7–8.7°C in northernmost Honshu, 7.2–8.4°C in the central mountains, 6.5°C in the Chugoku District, and 5–6°C in Kyushu. The probable annual precipitation ranged from 1050 to 1300 mm along coasts in southwestern Japan during the culmination of the last glaciation.

This paper considers a model of cold and dry full-glacial climates for the southwestern United States in the light of published studies. The evidence from fossil plants is shown to be reconcilable with temperatures some 10°C below their present levels and a concomitant shift of the upper timberline which varied according to regional summer lapse rates. Fossils of “thermophilous” or “mesophytic” plants are cited by some writers as evidence for mild, pluvial conditions although today these plants occur in relatively cold and dry situations. Mean annual and July temperatures for the United States as a whole, derived from the model, are in accord with periglacial and palynological evidence.

The Holocene history of the Danube Delta has been studied using 14C analyses of faunal material. The principal phases of development include: (1) initial Letea Caroarman spit, 11,700–9800 yr B.P. in its central part, 8800-5500 yr B.P. in its southern part; (2) Sf. Gheorghe I Delta, 8900-7200 yr B.P.; (3) Sulina Delta, 7200-2000 yr B.P., and (4) Sf. Gheorghe II Delta-Chilia Delta 2000 yr B.P.-present. Other smaller-scale features have also been dated, including secondary deltas (Coşna and Sinoe Deltas) and littoral bars. Age determinations carried out on whole samples were erratic and it was found that individual species had to be separated and dated. In all cases, the older dates were of transported material whereas the younger dates gave the true age of the formation.

Until recently, the oldest-known packrat (Neotoma spp.) midden records of desert scrub vegetation were less than 10,500 yr old and were restricted to altitudes below 300 m in the northern Sonoran Desert. Recent discovery of macrofossil assemblages in the Mojave Desert extends the record of desert vegetation back to 14,800 yr ago and to altitudes as high as 910 m. Although xerophytic conifer woodland was widespread in current desert habitats during the Late Wisconsin and early Holocene, the development of extensive desert vegetation was not delayed until the beginning of the middle Holocene. A regional vegetation mosaic of desert scrub and woodland existed at altitudes below 1000 m in the Mojave Desert during the last part of the Late Wisconsin.

Defining the spatial and temporal limits of vegetational processes such as migration and invasion of established communities is a prerequisite to evaluating the degree of stability in plant communities through the late Quaternary. The interpretation of changes in boundaries of major vegetation types over the past 20,000 yr offers a complementary view to that provided by migration maps for particular plant taxa. North of approximately 43°N in eastern North America, continual vegetational disequilibrium has resulted from climatic change, soil development, and species migrations during postglacial times. Between 33° and 39°N, stable full-glacial vegetation was replaced by a relatively unstable vegetation during late-glacial climatic amelioration; stable interglacial vegetation developed there after about 9000 yr B.P. Late-Quaternary vegetation has been in dynamic equilibrium, with a relatively constant flora, south of 33°N on upland interfluves along the northern Gulf Coastal Plain, peninsular Florida, and west-central Mexico.