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251.
In 1992, Mark Seeman proposed the existence of a Jack's Reef horizon in Ohio. Little professional research has been undertaken on domestic sites since then though. The Jack's Reef horizon subsumes the Intrusive Mound complex. Archaeological excavations for the Rockies Express-East gas pipeline project identified three sites in the central Scioto valley that provide evidence of Jack's Reef horizon occupations in floodplain and upland settings flanking the river valley. Radiocarbon dates confirm habitation associated with this late Late Woodland culture from cal A.D. 630–1000. Excavation and geophysical data reviewed in this article indicate intensive habitation of large base camps and small-scale residential bases, with secondary refuse disposal, distinctive ceramics, a curated bifacial lithic technology, and an expedient flake-tool technology.  相似文献   
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This paper describes the design and construction of the side‐wheel steamer Heroine, a representative of the ‘western river steamboat’ type and the earliest example of its kind to undergo archaeological study. Heroine was built at New Albany, Indiana, in 1832 and sunk on the Red River between Oklahoma and Texas in 1838. The extensive remains of the lower hull show assembly practices in use during the developmental era of Mississippi River steamboats. The wreck also reveals a heretofore‐unknown technique for longitudinally strengthening these long, narrow, and very lightly built hulls.  相似文献   
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In the context of an archaeological survey of the southern Argolid, Greece, studies have been carried out to elucidate the evolution of the landscape since its earliest known human occupation about 50,000 years ago. One of these studies was a detailed geological mapping of the late Quaternary alluvium and soils in the area. Dated by means of thorium-uranium disequilibria, archaeological finds, and historical information, seven periods of alluviation were identified, each of short duration relative to long intervening periods of stability and soil formation. The three earliest alluvial phases, falling before and during the last glacial interval, range from about 330,000 to 32,000 years in age. No alluviation accompanied the last glacial maximum around 20,000 years ago. In fact, a stable landscape persisted until about 4500 years ago, when debris flows and widespread aggradation in the valleys resulted from major slope destabilization and soil erosion, probably as a result of extensive land clearance in the Early Bronze Age. A subsequent stable period lasted through the many upheavals of the later Bronze Age, the Dark Ages, and the early historical period. It came to an end with a brief phase of alluviation between about 300 and 50 BC. Stability returned through the late Roman period, notwithstanding considerable expansion of the settled area. Another period of destabilization, this one marked by debris flows and hence major soil erosion, is poorly fixed in time, but probably coincides with expanded maquis clearance accompanying the resettlement of the area around AD 1000. Subsequent events of soil erosion and aggradation vary in nature and timing from one drainage to the next and, in some areas, continue today.Nature and chronology of the soil forming and alluviation events show that simple correlations with climatic events do not suffice to explain them. For the latter ones, past about 2500 BC, human activity seems to be the dominant cause, but once again the relation between cause and effect is not straightforward. Land clearing, or neglect of soil conservation efforts during economic downturns, appear to have a more devastating effect upon the landscape than do intensive land use or total land abandonment.  相似文献   
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