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The Lubbock Lake site, on the Southern High Plains of Texas, contains one of the most complete and best-dated late Quaternary records in North America. A total of 117 14C dates arc available from the site, determined by the Smithsonian and SMU Laboratories. Of these dates, 84 have been derived from residues (humin) and humates (humic acids) of organic-rich marsh sediments and A horizons of buried soils. Most of the ages are consistent with dates determined on charcoal and wood, and with the archaeologic and stratigraphic record. The dates on the marsh sediments are approximate points in time. Dates from the top of buried A-horizons are a maximum for burial and in many cases are close to the actual age of burial. Dates from the base of the A-horizons are a minimum for the beginning of soil formation, in some cases as much as several thousand years younger than the initiation of pedogenesis. A few pairs of dates were obtained from humin and humic acid derived from split samples; there are no consistencies in similarities or differences in these age pairs. It also became apparent that dates determined on samples from scraped trench walls or excavations that were left open for several years are younger than dates from samples taken from exactly the same locations when the sampling surfaces were freshly excavated.

The changing character of vegetation and the effects of disturbance on vegetation are inferred from pollen, plant macrofossils, charcoal, and microlepidopteran larvel head capsules in sediment cores from Upper South Branch Pond, Maine. Following deglaciation 12 500 – 12 000 years ago, a herb–shrub tundra developed which included moss species characteristic of calcareous, mineral soils. Fire and infestation by microlepidopterans were unimportant initially but became important upon arrival of spruce, paper birch, balsam fir, white pine, and tamarack trees (ca. 10 200 – 9500 years BP). Fires were infrequent in the watershed between 7500 and 5000 years BP. The relatively stable forests of this period, dominated by hemlock and yellow birch, grew in what may have been the moistest part of the Holocene. The maximum postglacial abundance of microlepidopteran larvae is centered around the hemlock decline (ca. 4800 years BP). Subsequently, the forest was composed largely of deciduous trees and white pine. Fire incidence was greater, and fewer fossils of microlepidoptera were deposited. Lack of major disturbances between ca. 3300 and 2600 years BP coincided with increases in hemlock, tamarack, yellow birch, and arbor vitae. Increases in boreal conifers began by about 1700 years ago, suggesting cooler, and perhaps wetter, climate. An increase in microlepidoptera accompanied the recent expansion of boreal conifers.

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.