ABSTRACT
Archaeologists are repeatedly confronted during their excavation careers with maddeningly complex physical situations. In the American West, they may find that a herd of bison was driven into an arroyo and some 190 of them killed and then butchered, leaving a bewildering mass of bones and artifacts, the whole later modified by erosion. That was what Wheat (1972) and his associates encountered at the Olsen-Chubbuck site. In the Middle East, they may find multilayered jumbles of mud-brick walls intermingled with burials, trash, burned-down buildings, all modified by later construction, casual looting, and prehistoric antiquarianism. Dry caves and deserts may yield exquisitely preserved materials and plant remains, but often in the context of dust as fine as talcum powder and sand that runs like water when disturbed. Shell middens in North and South America, geologically rearranged deposits in East Africa, pithouse villages in China, and Maya ruins in Yucatan all present their own unique problems of excavation.
