American Recovery and Reinvestment Act 2009 Section 110 Compliance Report for the U.S. Army Corps of Engineers, St. Louis District, NHPA, Cultural Resources Investigations, Technical Report No. 34 (Volume 3)(Part 1), Shoreline Survey of the Lower 80 Miles of the ILlinois River Brown, Cass, Pike, Mo

Shoreline Survey of the Lower 80 Miles of the Illinois River Brown, Cass, Pike, Morgan, Scott, Calhoun, Green, and Jersey Counties, Illinois.

Bear Creek Archeology, Inc. undertook a 4.6 m wide bank site survey along the lower 80 miles of the Illinois River. Seventy-two sites were examined and the soil profile recorded. Limited auger testing supplemented the profile at 18 sites. At 17 sites, datum rods were placed and measured from the scarp for erosion monitoring. Conclusions are that navigation, i.e., maintenance of the channel and boat wave action, are the primary adverse effects to the bank sites. High water levels have caused extensive bankline retreat over the past 100 years and recent deposition of sediment on many of the banks. Thirteen sites are interpreted to either be destroyed by erosion or redeposited artifacts and are recommended not eligible for the NRHP. At 27 site plots, no artifacts were found, but landforms capable of containing sites are present and Phase I survey is recommended. Twenty-six sites produced artifacts and have prehistoric landforms that conform to the artifacts. These sites are potentially eligible for listing to the NRHP and Phase II testing is recommended. Six sites are recommended NRHP eligible and for erosion monitoring and Phase III data recovery.

伊利诺伊河下游80英里岸线勘测：覆盖伊利诺伊州布朗（Brown）、卡斯（Cass）、派克（Pike）、摩根（Morgan）、斯科特（Scott）、卡尔霍恩（Calhoun）、格林（Green）及泽西（Jersey）县。熊溪考古公司（Bear Creek Archeology, Inc.）对伊利诺伊河下游80英里河段开展了宽度为4.6米的岸址勘测，共踏勘72处岸址并记录土壤剖面；针对其中18处岸址，通过有限的螺旋钻取样测试补充完善了剖面数据；另在17处岸址设置基准杆，从陡崖处开展测量以用于侵蚀监测。勘测结论显示：航道维护与船舶浪击等航运活动是对岸址造成负面影响的主要因素。过去百年间高水位导致岸线大规模后退，近期多数岸段又出现了泥沙沉积现象。经研判，13处岸址要么已遭侵蚀破坏，要么仅存再沉积的人工遗物，因此不具备列入美国国家历史遗迹名录（National Register of Historic Places，NRHP）的资格。在27处岸址地块中未发现人工遗物，但存在具备承载考古遗址潜力的地貌单元，建议开展第一阶段勘测（Phase I）。26处岸址发现了人工遗物，且其史前地貌与出土遗物特征相符，这些岸址具备列入NRHP的潜在资格，建议开展第二阶段测试（Phase II）。另有6处岸址被认定符合NRHP列入资格，需开展侵蚀监测并进行第三阶段数据恢复（Phase III）工作。