The southeastern coast of South Africa's Cape Province underwent complex geomorphic evolution during the late Cenozoic, leaving a variety of erosional forms and a detailed, complementary record of distinctive sediments. The latter include several new lithostratigraphic units and paleosol horizons. An almost ubiquitous planation surface, the 200-m Coastal Platform, is associated with the fanglomeratic and deltaic Keurbooms Formation (late Tertiary?). A major sea level at +120 m truncated a laterite paleosol and was followed by accumulation of land rubble and littoral deposits to 101 m, constituting the Formosa Formation. Then follow sea level stages at +60, +30, and +15–20 m, as well as several generations of weathered eolianite, including the Brakkloof Formation with the deep superposed Brakkloof Soil. Beaches at +5–12 m, with thermophile mollusca and C14 dates of >40,000 yr mark the Swartkops horizon, probably of Eem interglacial age. Next are cryoclastic screes and cave deposits, and ultimately the podsolic Brenton Soil of the Würm Interpleniglacial. Transgressive eolianites and coastal dunes after 16,000 BP were interrupted by pedogenesis ca. 7500 BP and stabilized after 4200 BP when sea level reached +2.5 m. Geomorphic instability in stream valleys after 1000 BP was followed by man-induced activation of the coastal dunes, since the late 18th century. Environmental patterns accompanying this succession at various times included (1) semiarid pediplanation, (2) interior dune formation, and (3) intensive, cold-climate denudation, all under open vegetation in what is now closed, humid forest; by contrast, some of the more aberrant paleosols indicate warmer, perhumid conditions.
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.
For southeastern Australia, arrival of the First Fleet in 1788 raises similar issues in environmental history as the 1492 landing of Columbus in the Americas. But Anglo‐Australian settlement is younger and better documented, both in terms of scientific proxy data and historical sources, which include data on stocking rates that generally were light. Environmental concerns were voiced early, and a lively debate continues both among professionals and the lay public, with Australian geographers playing a major academic and applied role. This article addresses environmental degradation often attributed to early pastoralism (and implicit clearance) in the Tablelands of New South Wales. Methods include: (1) comparison of well‐reported travel itineraries of 1817–1833 with modern land cover and stream channels; (2) critical reviews of high‐resolution pollen profiles and the issues of Aboriginal vs. Anglo‐Australian fire ecology; and (3) identification of soil erosion and gullying both before and after Anglo‐Australian intrusion. The results indicate that (a) land cover of the Tablelands is little changed since prior to Contact, although some species are less common, while invasive genera of legumes have modified the ground cover; (b) the charcoal trace in pollen profiles prior to Contact supports an ecological impact of regular Aboriginal burning and rare, catastrophic fires; and (c) most stream channels were already entrenched (“gullied”) well before 1840, with repeated cut‐and‐fill cycles during the late Holocene, but before Contact. Land impairment has not been a major problem on the Tablelands, although the last two centuries have experienced cumulative and complex environmental change. This unexpected empirical picture suggests that, until high‐technology intervention, increasing periodicity/magnitude of extreme drought/precipitation events had been the overriding trend in interior New South Wales, perhaps reinforced by burning. There is no support for an apocalyptic model of colonial environmental history.
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