The energy required to sustain midlatitude continental glaciations comes from solar radiation absorbed by the oceans. It is made available through changes in relative amounts of energy lost from the sea surface as net outgoing infrared radiation, sensible heat loss, and latent heat loss. Ice sheets form in response to the initial occurrence of a large perennial snowfield in the subarctic. When such a snowfield forms, it undergoes a drastic reduction in absorbed solar energy because of its high albedo. When the absorbed solar energy cannot supply local infrared radiation losses, the snowfield cools, thus increasing the energy gradient between itself and external, warmer areas that can act as energy sources. Cooling of the snowfield progresses until the energy gradients between the snowfield and external heat sources are sufficient to bring in enough (latent plus sensible) energy to balance the energy budget over the snowfield. Much of the energy is imported as latent heat. The snow that falls and nourishes the ice sheet is a by-product of the process used to satisfy the energy balance requirements of the snowfield. The oceans are the primary energy source for the ice sheet because only the ocean can supply large amounts of latent heat. At first, some of the energy extracted by the ice sheet from the ocean is stored heat, so the ocean cools. As it cools, less energy is lost as net outgoing infrared radiation, and the energy thus saved is then available to augment evaporation. The ratio between sensible and latent heat lost by the ocean is the Bowen ratio; it depends in part on the sea surface temperature. As the sea surface temperature falls during a glaciation, the Bowen ratio increases, until most of the available energy leaves the oceans as sensible, rather than latent heat. The ice sheet starves, and an interglacial period begins. The oscillations between stadial and interstadial intervals within a glaciation are caused by the effects of varying amounts of glacial meltwater entering the oceans as a surface layer that acts to reduce the amount of energy available for glacial nourishment. This causes the ice sheet to melt back, which continues the supply of meltwater until the ice sheet diminishes to a size consistent with the reduced rate of nourishment. The meltwater supply then decreases, the rate of nourishment increases, and a new stadial begins.

Cores from five high alpine basins in the northern San Juan Mountains show several fluctuations in lithology. Typically, peats are interbedded with coarser clastic sediments or else woody peats alternate with fibrous peat. Twenty 14C dates provide radiometric control. Sediment rates averaged about 2.5 cm/100 yr but varied at the different sites between 1.19 and 50 cm/100 yr. Rates were lower during the middle of the Holocene. Basal radiocarbon dates indicate that these high (ca. 3600 m a.s.l.) northeasterly facing cirques were icefree by 9000 BP. There is some evidence in the cores for a short climatic reversal sometime between 8000 and 7000 BP. A major change occurred in the high basins very close to 5000 BP and thereafter there are several intervals of increased clastic sedimentation which may be related to Neoglacial climatic fluctuations. Analysis of a 2.15 m core near Hurricane Basin indicates significant fluctuation of pollen and macrofossils occurred during the 9000 ± year record. The Picea/Pinus ratios are used to delimit changes in the apparent elevation of the site: the ratios indicate that a short drop of “treeline” occurred about 8000 BP and then remained near present level until about ≥1800 BP when the apparent elevation of the site rose. Macrofossils indicate that spruce was present in the Hurricane Basin (and others) at specific periods and confirms the general results of the Picea/Pinus ratios. The San Juan Mountains do not possess a glacial Neoglacial record but the stratigraphy of these high cirque basins can be used to define glacial stades (cf. Jardine, 1972). The interpreted climatic response record on vegetation and sediment flux has both similarities and differences from other records in the western mountains of North America.

Stratified scree in the Porters Pass area of the South Island New Zealand consists of up to 30 m of alternating bands of angular gravel and gravelly silt. The gravel consists of frost-shattered bedrock, while the silt appears to have originated from weathered till that entered the area as loess. Every 10 m of stratified scree actually contains at least 5 m of loess. Glaciers left oversteepened slopes on which screes subsequently formed, probably during later nearby glacial advances. The more gently sloping land may have been covered in vegetation as dense as today, but every l0-118 yr, widespread destruction of the vegetation resulted in a marked period of loess deposition. Thus the stratified scree of Soons (1962) has a different origin to that postulated for the grezes litées of European workers.

Emergent Pleistocene sea level indicators in the northern Bahamas include: a bioerosional notch at +5.3 to 5.9 m; sea caves, notches, and marine terraces at about +4.3 m; and lithified coral rubble and reef deposits between 0 and 3 m. Thorium 230 dates of the fossil corals, which were deposited as these features were being produced, span the age range from 100 to 145 thousand years BP with a majority falling between 115 and 130 thousand years BP. The notch at about +5.6 m is interpreted to be the product of a sea level stand 125 thousand years BP, while the features at +4.3 m are believed to be formed sometime later as sea level fell from the higher position. Part of the age span is inherent in the dating technique and possible sample alteration. Another cause of the spread may be mixing of corals of different ages into a single deposit.

Detailed X-ray diffraction analysis of cores taken in the eastern equatorial Atlantic suggest that during approximately the last 600,000 yr a relatively constant background of clay mineral deposition has existed on which are superimposed large oscillations in quartz input (relative to illite). The quartz is transported from the Sahara Desert by the northeast trade winds and the quartz/illite oscillations appear to reflect past changes in the transporting effectiveness (intensity) of the trade winds. Comparison of the quartz/illite variations with paleotemperature variations for the northeast Atlantic suggests that major inputs of quartz correlate with cold periods and that warm periods correlate with low quartz input. The parallelism between the curves indicates a fundamental link between trade wind intensity and past climatic fluctuations, and further suggests that the changes of intensity are closely atuned to temperature fluctuations in the northern latitudes. The relationship between the quartz/illite variations and wind intensity is complicated by the fact that other climatically controlled factors may also affect quartz deposition in the equatorial Atlantic.

Planktonic foraminiferal assemblages have been examined in 25 trigger core top samples and 51 piston core top samples collected between latitudes 28° S and 55° S and longitudes 79° E and 120° E from the southern Indian Ocean during cruises of the U.S.N.S. Eltanin. Samples taken from water depths exceeding 4000 m and/or showing evidence of calcium carbonate dissolution were eliminated from further analysis. The final piston core data set consists of 34 samples; the trigger core data set containing 21 samples. A close relationship exists between changes in the planktonic foraminiferal assemblages in the surface sediments and surface water temperatures. Species diversity values were computed for each of the core top assemblages using the Shannon-Wiener Index and the Brillouin Index, each of which takes into consideration the number of species and the proportionment of individuals among the species. The Shannon and Brillouin diversity values for all samples are positively correlated (correlation coefficient (r) = +.999). Regression analysis of latitude versus Shannon diversity values in the trigger core samples clearly shows a decrease in diversity with increasing latitude (r = −.979). Furthermore, a strong correlation (r = +.977) exists between decreasing species diversity (Shannon) and decreasing average summer-winter temperature of the overlying surface waters. A paleotemperature equation derived from the relationship of diversity in trigger core samples and surface water temperature was used to generate paleotemperature curves for five trigger cores and a 6 m piston core of Late Pleistocene age, located beneath the present position of the Subtropical Convergence. A 7–8° C temperature range is suggested between the interglacial and glacial episodes in this Late Pleistocene sequence, and probably reflects latitudinal shifts of the Subtropical Convergence and Australasian Front during the Late Pleistocene.

Several factors influence the long-term 13C record of the organic component in lake sediments. Two of the more predominant ones are changes in hardness of the water and changes in organic productivity. In general, during colder climatic episodes, 13C values are lower. Of 12 lakes studied, 4 have 13C records with large changes in 13C content that are to a certain degree correlative with climatic changes.

The mean apparent radiocarbon ages of marine shells, colleted alive before the initiation of atomic bomb testing, and also before the main input of dead carbon derived from fossil fuels, are found to be 440 yr for the coast of Norway, 510 yr for Spitsbergen, and 750 yr for Ellesmere Island, Arctic Canada. The relationship between these apparent ages and the oceanic circulation pattern, is discussed. Also possible variations of the apparent ages back in time are discussed.

The relative frequencies of different skeletal elements within the bone assemblage recovered from a late Pleistocene fissure fill at Swartklip (South-Western Cape Province, South Africa) are shown to resemble those in the assemblage from the Transvaal australopithecine site of Makapansgat. Since there is evidence that carnivores, probably hyenas, accumulated the bones at Swartklip, it follows that carnivores, rather than hominids, may have accumulated the bones at Makapansgat.

The Northwestern Plains provide evidence of human occupation from Clovis times. The human groups involved were not spectacular and operated at the band level as hunters and gatherers. Changes in climate during the Altithermal Period may have caused some shifts in animal populations as a result of aridity with concomitant shifts in human occupations. The human groups were not adapted to storage of large quantities of food and as a result were operating in close harmony with the environment. Interdisciplinary efforts are needed to further resolve the past activities of human groups on the Plains.