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Evidence from several disciplines supports the proposition that following the Wisconsinan and an initial but brief moist phase of the Holocene, there was a gradual drying trend in the mid-continent Prairie Peninsula that peaked about 7000 years ago, a pattern that was not reversed until about 4000 years ago. Except for minor perturbations, conditions during the past four millennia have essentially been similar to those of the present. Studies in palynology and geomorphology have shown that the climatic regimes of the early/mid Post-glacial had a marked influence on both the biota and landscape erosional patterns, especially along the margins of the Prairie Peninsula. Measurable changes in the landscape and attendant biota show a time-transgressive pattern of drought related phenomena recorded palaeo-ecologically from west to east.Few studies of archaeological sites in the Prairie Peninsula have examined the evidence in and around the sites themselves for data reflecting local environmental dynamics. In fact, earlier models proposed for explaining the evolution of food-procuring systems in eastern North America virtually ignored potential changes in the natural environment. This paper examines data from two archaeological sites along the prairie-forest border in Missouri that contain long cultural sequences. Evidence is presented that pronounced changes in the natural environment occurred and that these biophysical variables are indeed critical for understanding the evolution of food-procuring societies in the American Midwest. 相似文献
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David Jacoby 《Journal of Medieval History》1977,3(3):225-264
This case-study is the first attempt to examine a commercial outpost in the Crusader Levant within the context of the commercial and colonial expansion of its mother-city and in direct relation to its particular features. The Venetian quarter in Acre in the second half of the thirteenth century provided the physical setting for the exercise of authority by the state and a solid base for the expansion of its dominion. The Venetian administration there implemented the strict regulation of commerce and shipping enacted in Venice in this period, including several rules stemming from the particular needs of Acre. Various families of settlers from Venice, nobles as well as popolani, can be traced for several generations; the grant of Venetian status to natives of the Latin kingdom of Jerusalem, Latins oriental Christians, and Jews, enlarged the size of the Venetian population in Acre. The fate of the refugees who escaped from the city in 1291 is the last topic to be examined. 相似文献
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