Alluvial Geoarchaeology: Floodplain Archaeology and Environmental Change. A. G. Brown. Cambridge University Press, Cambridge, England, 1997. xxiii + 377 pp. £55 (cloth) or £19.95 (paperback).
Reviewed by Donald Thieme, Geoarcheology Research Associates, 5912 Spencer Avenue, Riverdale, NY 10471.
This book breaks much new ground, ranging over more of the globe and extending over a longer time frame than the standard reference from a North American perspective. Brown endorses a multi-disciplinary approach, integrating faunal, floral, and fluvial changes. This brings "multiple stratigraphies" as developed at Franchthi Cave into open, alluvial settings. The time depth of Old World prehistory enables correlation with the oxygen isotope timescale and encompasses interglacial environments which differ from the present but can be systematically compared. The archaeological perspective is timely and sophisticated, showing an awareness of British post-processualism and emphasizing human impacts on alluvial valleys.
Browns strongest suit is his discussion of sites and rivers in the UK, particularly the Thames and Severn sequences. He pays appropriate attention to the unique depositional settings of the lower Thames in which were found the hominid fossils at Swanscombe (p. 162-164) and associated Paleolithic industries at Clacton-on-Sea (p. 164-167). Independent stratigraphic sequences at Swanscombe include lithology, paleosols, molluscan fauna, and Uranium series age estimates which can be correlated by erosional hiatuses. Less well known sites along tributary streams are also summarized, however, including: Sproughton along the river Gipping (p. 197), Shippea Hill along a paleochannel of the Little Ouse (p. 203-206), and Thatcham at the margin of an early Holocene floodplain lake in the valley of the river Kennett (p. 206-208).
Browns discussion of North American alluvial geoarchaeology (p. 167-184) is weaker and should be considerably revised for future editions. Archaeological sites and "regions" mentioned in the text are supposed to be plotted on Figure 5.7 but several of the most important are missing and the discussion is poorly organized. He seems to have intended the organization to follow the route of migration, which means that Clovis is not actually discussed until near the end (p. 174). Figure 5.7 labels the entire Brazos River "Blackwater Draw" and neither Folsom nor Dent are plotted. Figure 5.8 duplicates Vance T. Hollidays map of sites in the vicinity of Kersey, Colorado which Figure 5.7 indicates as the "Kersey and Jurgens sites." The sites that Holliday studied are Jurgens, Frazier, Klein, and Powars (Brown has "Powers" on p. 170). These may be minor errors but their abundance suggests a lack of attention to detail.
Although Brown makes some interesting comparisons both within North America and between the work of North American and British geoarchaeologists, he sometimes lacks historical perspective. His discussion of the American Southwest, e.g. the "Sulphur Springs valley" is plotted on Figure 5.7 but human remains of Sulphur Springs woman are discussed several pages before the discussion of the Whitwater Draw site (p. 175) and the pioneering study by Sayles and Antevs is not cited. The "Santa Cruz" label on Figure 5.7 refers to the San Xavier reach of the Santa Cruz River studied by Waters which is not in fact an archaeological site. Brown could have discussed recent paleoenvironmental studies on the Colorado Plateau in this section, and the studies of Hohokam canals beginning with Haurys work at Snaketown would have been a nice addition to his chapter on "Managed Floodplains."
Browns summary of hydrographic changes in the Nile basin comes at the beginning of the book (p. 1-13) but encapsulates many of the issues raised in subsequent chapters. He uses a flowchart (p. 5) to suggest linkages between climate change, drainage basin responses, and cultural phenomena ranging from agricultural technology to patterns of social and political organization, to mythology. Management of the Nile flood included construction of canals, dikes to contain floodwaters and facilitate transport, embankments, and in upper Egypt the construction of large floodbasins (p.9). A later chapter on "managed floodplains" features Browns own research on the Middle Severn fish weirs (p. 259-261) of the UK which were large enough to hinder river navigation in the 13th and 14th centuries AD.
Alluvial Geoarchaeology is an essential addition to the library of anyone practicing "geo-archaeology" today, from whichever side of the hyphen we originate academically. The books weaknesses are perhaps to be expected since it breaks so much new ground. Brown summarizes flume studies and field experiments with artifacts and bones (p. 91-96) which probably are not referenced in extant geomorphology texts. He seems unaware, however, of much relevant literature on taphonomy and formation processes from paleontologarchaeological method and theory (e.g. Sdating methods (p. 48-58) is merely adequate although he includes a unique discussion of the use of artifacts for relative age control (p. 58-59).
Brown mixes terms from several European chronologies in a manner that will confuse rather than enlighten North American readers (e.g. Table 5.2 on p. 156). The use of the oxygen isotope chronology is pioneering and may be helpful for students with previous exposure to geochronology. Soils are discussed using the UK system with only marginal reference to the more traditional USDA or FAO soil taxonomies (p. 96-97). Examples of paleosol indications of climates different from the present are also drawn exclusively from the UK (p. 100-103). Micromorphology is mentioned briefly (p. 101-102) and illustrated with an example from the pre-Neolithic in the lower Welland valley in eastern England. The chapter on floodplain ecology and paleoecology (p. 104-146) is strong but omits the "dendrogeomorphology" techniques widely applied in the United States.
University instructors may not find this "manual" easy to incorporate into either undergraduate or graduate curriculae, at least in the United States. The books conceptual sophistication means that it will not stand alone as a primer on geomorphology for archaeologists. The fundamentals of fluvial geomorphology are covered in two appendices but instructors will need to suplement it with more orthodox texts and primary literature for most teaching purposes. Even some graduate students in the United States may be scared off by Browns heralding of "the complexity of terrace deposition, the importance of thresholds, and the multiplicity of conditions under which aggradation and incision may occur (p. 151)." Instructors in several fields should consider assigning individual chapters. Chapters 6 and 8 would be particularly applicable for a course in Old World Archaeology, for example. Brown does an excellent job of linkinritish Isles, continental Europe, and the Near East to Holocene environmental change and the environmental consequences of human settlement.