Very little is known about the prehistory of Siberia prior to the Sartan (“Main Würm” = “Main Wisconsin”) Stadial of the Last Glacial. It is not yet clear whether this is result of the inadequacy of investigations so far or of the fact that human occupation was relatively limited in pre-Sartan times. The Sartan occupation of Siberia has been well documented by the discovery of a relatively large number of open-air sites in the major river valleys of the region. The large numbers of broken-up animal bones found at many of these sites, in combination with rich inventories of bone and stone artifacts and remains of structures, hearths, ect., show that the Sartan inhabitants of Siberia were comparable in level of cultural development to their European (Upper Paleolithic) contemporaries. More particularly, they seem to have been effective big-game hunters, fully capable of exploiting the comparatively rich game resources of their open country environment. As in Europe, evidence from Siberia suggests that the environmental change (especially reforestation) which took place at the end of the Last Glacial led to decreased reliance on big-game hunting and increased emphasis on other modes of subsistence, especially fishing.

Les mesures du rapport isotopique 18O/16O le long de l'axe de stalagmites soigneusement choisies donnent u̇n enregistrement climatique continental qui peut être comparé aux données de la paléoclimatologie océanique. Les âges des différentes couches de la stalagmite sont établis soit par la méthode du carbone 14 pour la période de 0 à 35.000 ans b.p., soit par le rapport 230Th/234U jusqu'à 300.000 ans b.p.

La validité de cette méthode est discutée et une application en est donée pour la période allant de 130.000 à 90.000 ans b.p.

Measurements of the isotopic ratio 18O/16O along the axis of carefully chosen stalagmites give a continental climatic record which can be compared to oceanic paleoclimatological data. Ages of stalagmite layers are established either by carbon 14 for the period 0 to 35,000 years b.p. or by 230Th/234U ratio until 300,000 years b.p.

The validity of this method is discussed and an application is given for the period 130,000 to 90,000 years b.p.

The thermodynamic model of J. Adem has been applied to the determination of Arctic and hemispheric surface temperatures with both ice-covered and ice-free states of the Arctic Ocean. The effect of glaciated and nonglaciated continents is included in the investigation. With an ice cover over the Arctic, as at present, computed temperatures for the polar sea and the Northern Hemisphere correspond closely with present observations. Over a broad range of the critical parameters, removal of the ice cover yields computed temperatures that remain well above freezing level throughout the year. With glaciated continents computed Arctic temperatures are depressed.

The thermodynamic ocean of the Sillen school offers little incentive to those who search the sedimentary record for evidence of changes in ocean chemistry during Cenozoic time. Their models predict a uniform chemical composition. However as the sediments presently accumulating in the ocean show little evidence of equilibration with the overlying water, the possibility that kinetic factors play an important role must be seriously explored. Such a model is presented in this paper. Material balance restrictions are substituted for some of the usual chemical equilibria. The role of organisms is shown to be dominant for at least some of the important components of sea salt (i.e., C, N, P, Si, …). If, as proposed here, the chemistry of sea water is dependent on rates of supply of individual components, the rate of vertical mixing in the sea, and the type of material formed by organisms, then substantial changes in the chemical composition have almost certainly taken place. Several means by which such changes might be reconstructed from chemical and isotopic measurements on marine sediments are discussed.

Deposits of Quaternary age from the Rocky Mountains to the Pacific Coast in the western conterminous United States represent a great variety of environments. The deposits include those of continental and alpine glaciers, glacial meltwater streams, nonglacial streams, pluvial lakes, marine environments, eolian environments, and masswasting environments. On two charts we have attempted to correlate representative sequences of deposits of many of these environments, based on published sources and recent unpublished investigations. Evidence for correlation is based mainly on stratigraphic sequence, soil characteristics, the amount of subsequent erosion and interlayered volcanic ash beds identifiable as to source. Chronologic control is based on numerous radiocarbon dates, U-series dates on marine fossils, and K-Ar dates on volcanic rocks. The Bishop volcanic ash bed and one of the Pearlette-like volcanic ash beds appear to represent significant regional key horizons, respectively about 700,000 and 600,000 years old. Rock magnetism is shown to suggest the paleomagnetic polarity at the time of rock deposition. Assigned land-mammal ages of included fossils help to put limits on the age of some units.

Slope deposits in the Snowy Mountains of south-eastern Australia have a wide distribution above 1000 m elevation on slopes between approximately 5° and 25° which are well stabilized by the existing forest vegetation. The present environment is not severe enough to initiate slope instability.

The slope deposits consist of fines with gravel and angular stones showing preferred downslope orientation, overlying a generally smooth substrate of weathered bedrock. Pockets and lenses of relatively stone-free organomineral soil containing fragments of carbonized wood sometimes occur near the interface between the slope deposits and the weathered bedrock. Fragments of the carbonized wood carefully selected from three sites in different catchment areas several kilometers apart have similar radiometric ages of between 31,000 and 34,000 years.

The properties of the slope deposits and the context of the site and climatic conditions in which they now occur point to an origin under periglacial conditions commencing 31,000–34,000 years ago, associated with deep seasonal freezing and thawing although not necessarily with permafrost. It is estimated that a substantially lower mean annual temperature, at least 8–10°C less than the present, would have been necessary to produce periglacial conditions down to 1000 m in the Snowy Mountains. On the evidence of similar slope deposits elsewhere in south-eastern Australia, this major cold period was evidently widespread.

Climatic conditions prior to the onset of the cold period appear to have been generally similar to those of today, except perhaps for rather moister and cooler summers.

Un forage réalisé en 1966 dans le récif-barrière de la côte sud-ouest de Nouvelle-Calédonie a traversé, avant d'atteindre un substratum éocène à la profondeur de 226 mètres, un ensemble sédimentaire carbonaté divisé en 5 grandes unités lithologiques. L'examen de ces dernières révèle la présence, dès la base, de sédiments vraisemblablement post-miocènes, d'origine peu profonde, semblant s'être déposés durant une subsidence du socle. Le récif-barrière actuel, s'élevant d'une profondeur voisine de 70 mètres, parait être lié, au contraire, à la seule influence de phénomènes glacioeustatiques datant au plus du Quaternaire moyen.

Volcanic ash deposits whose source is the Cascade Mountains area were correlated on the basis of 19 elemental abundances obtained by instrumental neutron activation analysis (INAA). After activation of glassy separates in a TRIGA reactor, gammaray spectra were obtained and analyzed with computer programs. The elements Na, Sm, Sc, Fe, Ce, Hf, and Th were determined with relative standard deviations less than 5%; the precision for La, Co, Eu, Yb, Cs, Ba, and Lu was less than 17%; larger errors were obtained for Rb, Ta, Nd, Tb, and Cr. A statistical method was developed for correlation on the basis of relative elemental compositions unique to the ash deposits. Elemental abundances of Mazama glassy separates were independent of distance from the source. The site to site chemical variability of crystal rich Glacier Peak and St. Helens ash layers was greater than for Mazama and Newberry ashes. The Rb, Yb, Lu, Th, and Ta contents in Newberry glass were more than twice those in Mazama glass. The concentrations of trace elements in Glacier Peak and St. Helens ashes generally were less than one-half those in Mazama glass. The presence of Mazama ash has been confirmed at sites in Oregon, Washington, Alberta, and in sediments of the Pacific Ocean.

Twenty-nine samples of volcanic ash from the Pacific Northwest were analyzed by instrumental neutron activation techniques, with the aim of distinguishing among ashes from different sources. Preliminary results of petrographic studies of 42 ash or pumice samples are also reported. Geochemical characteristics of Mazama ash are defined, and problems induced by winnowing of crystalline material during transport and by weathering are discussed. Contents of La, Th, and Co, and La/Yb ratios are shown to be good discriminants. Data on refractive indices and on proportions of crystalline materials also aid in distinguishing among the various volcanic ashes studied. Ash and pumice found in archaeological contexts at Fort Rock Cave, Paisley Cave, Wildcat Canyon, and Hobo Cave are all from Mount Mazama, presumably from the culminating cruption of 7000 years ago.