Paleoecological and paleogeographical evidence is used to mold a framework from which the basic parameters of the late Quaternary glacial-age climate of tropical Australasia can be inferred. The theory of physical circulations, a knowledge of present tropical circulation patterns, and a study of anomalous and extreme events in the present era are used to reemphasize the view of a less pluvial tropical and subtropical zone at that time. Cooler sea-surface temperature, cooler trades, and the effect of the then exposed land areas are indicated as instrumental in producing drier conditions. Tropical areas west of Cape York Peninsula and Torres Strait were subject to fewer tropical disturbances and were similar to the present tropical savannah of the northern interior of Australia. Such effects would exist even without shifts in major climatic zones, although they are shown to be consistent with an equatorward shift of the westerlies brought about by the increased pole to equator temperature gradient. Paleoenvironmental evidence from the New Guinea Highlands and southeastern Australia suggests that their climates were anomalous. Substantial data of the glacial period in New Guinea show snow lines to be 1000 to 1500 m lower than at present which matches a 6 to 8°C lowering of temperature in highland New Guinea. The deep-sea cores of the CLIMAP Project suggest a mere 2°C cooling of the surrounding tropical oceans. It is shown that it is highly unlikely that an upper-level decrease in temperature of 6 to 8°C could be maintained while the surface cools by only 2°C. It is suggested that either the temperature of the tropical oceans of the western Pacific were overestimated by CLIMAP or that cold air incursions from higher latitudes (for which some analogs exist today) were sufficiently frequent to allow the maintenance of a snow line well below the freezing level of the ancient ambient tropical atmosphere. It is shown that in southeastern Australia considerable evidence of aridity cannot be explained by merely displacing the westerlies more equatorward. To account for the aridity, a new circulation pattern is proposed. Noting that there is CLIMAP evidence of preferred equatorward extension of sea ice, a pattern is postulated that displays only small seasonal change and is characterized by an enhanced Indian Ocean trough, marked ridging at eastern Australian longitudes, and a further trough in the western Tasman. Such a basic flow is consistent with (i) a low rainfall over southeastern Australia, (ii) frequent cold outbreak conditions favorable for the maintenance of the New Guinea glaciers, and (iii) considerable precipitation to nourish the ice caps of Tasmania and the Australian and New Zeland Alps.

The Gaap Escarpment is a dolomite cuesta demarcating the southeast margin of the Kalahari. Since Miocene-Pliocene times, thick masses of lime tufa have repeatedly accumulated at several points along this escarpment, and four regional sequences are described. These allow discrimination of six major depositional complexes, commonly characterized by basal cryoclastic breccias or coarse conglomerates that reflect frost shattering and torrential runoff, followed by sheets and lobes of tufa generated in an environment substantially wetter than today. A chronostratigraphy for the last 30,000 yr is provided by 14C dating, with direct or indirect correlations to the Vaal River sequence. The regional stratigraphy as well as faunal dating indicate an early Pleistocene age for Australopithecus africanus at Taung. Repeated episodes of protracted cold or wetter climate or both begin in terminal Miocene times, and the last Pleistocene cold-moist interval began after 35,000 yr B.P. and ended 14,000 yr B.P. Early and late Holocene times were mainly wetter, whereas the middle Holocene was drier than today. The paleoclimatic sequence differs from that of the southern and southwestern Cape or that of East Africa, but close parallels are evident throughout the lower Vaal Basin and the southern Kalahari. The tufa cycles provide a unique, 5,000,000-yr record of climatic variation in the Kalahari summer-rainfall belt that can be related to complex anomalies of the general atmospheric circulation.

Lithologic, paleontologic, and chronostratigraphic investigation of 13 gravity cores indicates the following environmental evolution: a high- (mid-) arctic period with a slight influx of ice-rafted debris occurred during the early middle Weichselian followed by a mid- (high-) arctic environment with a high influx of iceberg-rafted debris during the remainder of the middle Weichselian. The continental ice sheet probably did not extend beyond the inner shelf during middle Weichselian and a minimum relative sea level was ca. −120 m. A low-arctic environment occurred during (parts of) the late Weichselian with an initial winnowing of the sediments. The Norwegian Current entered the area during this substage. A high- (mid-) boreal environment occurred during the Holocene with high winnowing activity in the early Holocene. Winnowing is still very active on the shallower banks in contrast to the deeper banks where it has ceased. Relatively high percentages of carbonate in the form of biogenic skeletal remains occur in the Holocene sediments.

The varved sediments of the Santa Barbara Basin off southern California, offer a unique opportunity to study the changes in oceanographic conditions of this nearshore area during the last 8000 yr. Quantitative analysis of Radiolaria found in recent surface sediment samples from the eastern North Pacific allows the identification of four “assemblages” which can be related to the physical oceanography of the California Current. Two assemblages are associated with the southerly flowing California Current, one with the main stream of the current (California Current Assemblage) and the other with the offshore flow along northern California (Central Assemblage). The two other assemblages are associated with the subtropical region of the eastern North Pacific (Subtropical Assemblage) and one found mostly off the coast of Baja California (Baja Assemblage). Analysis of the Radiolaria found in the varved sediments of a core from the Santa Barbara Basin give an 8000-yr continuous record of these four assemblages. The California and Baja Assemblages show only minor fluctuations in their importance in the sediments of the Santa Barbara Basin. The California Assemblage, however, shows a steady increase during this time period. Prior to 5400 yr B.P. the Radiolaria were predominately subtropical in character, whereas after 5400 yr B.P. the Central Assemblage becomes more important. Since 5400 yr B.P. most of the changes in the radiolarian fauna consist of fluctuations in the importance of these two assemblages. Past sea-surface temperatures for the month of February were calculated using the transfer function technique of J. Imbrie and N. G. Kipp (1971, In “The Late Cenozore Glacial Ages” L. K. Turekian, Ed.), (Chap. 5, Yale Univ. Press, New Haven, Conn.). The time series of paleotemperature estimates show major changes in the average February temperature of Santa Barbara Basin waters. The range of estimated temperatures (12°C) exceeds that of the historical observations of February temperatures in the Santa Barbara Basin but does not exceed the observed range for the California Current region. The intervals from 800 to 1800 yr B.P. 3600 to 3800 yr B.P. and 5400 to the end of the record appear to have been generally warmer than today. Comparison of the Holocene record of alpine glacial advances with the radiolarian assemblage and paleotemperature time series shows that the initiations of advances was coincident with a decrease in sea-surface temperatures and an increase in the importance of the Central Assemblage in the Santa Barbara Basin. The terminations of these advances were not marked by any consistent characteristic in the Santa Barbara Basin time series.

Camelops have been recorded in a number of Paleo-Indian sites that lack evidence of past procurement methods. Recently, two occurrences of Camelops remains have been recorded in Paleo-Indian animal kills in Wyoming. One kill situation was in a Hell Gap cultural context that produced remains of a single Camelops taken along with about 100 bison in a parabolic sand dune trap. The other Camelops was in a Clovis cultural context and deals with a single animal believed to have been taken in an arroyo trap that was used to take bison at several Paleo-Indian time periods. Identification of geomorphic features involved in these kill sites offers a basis for beginning to interpret Paleo-Indian camel procurement methods.

A core section from the Fuquene area (Cordillera Oriental, Colombia) with a total length of 60 m shows a predominantly peaty-clay zone in the upper 12 m containing 15 laminae and thin layers of fine-grained, pyroclastic material. These 15 layers consist of crystal-vitric ash derived from dacitic-andesitic magmas. Mineralogic data and refractive index (r.i.) values of the associated glass shards make it possible to distinguish a lower group of mica-rich and an upper group of pyroxene-bearing ash layers. The successive layers illustrate a progressive increase of hydration of the shards with time and with decreasing particle size. The frequency distribution curves of the r.i. values of 8–4- and 75–50-μm shards are in general rather similar. Provisional pollen data and some radiocarbon dates allow comparison of the petrographic properties of these ashes with those of some ash occurrences in a nearby palynologically investigated core section. This comparison indicates that the mica-rich ashes were produced between about 44,000 and 20,000 yr B.P. and that the production of the pyroxene-bearing ashes took place after about 20,000 yr B.P. The petrographic features of a number of ashes, collected from sections and cores at different sites of the Sabana de Bogotá, appear to be comparable with those established in the sequence of Fuquene ashes. This suggests that these petrographic characteristics may be of use in correlation studies in the Sabana de Bogotá and adjacent areas.