Archaeological Investigations in the Adobe Dam Project Area

The Adobe 4 archaeological mitigation program was carried out at the site of a flood control dam to be constructed by the U.S. Army Corps of Engineers on Skunk Creek in north Phoenix, Arizona. The project area, which covers approximately 750 h, is situated 30 km north of the Salt River. Thus, it is located within the northern Hohokam periphery. This study presents information concerning prehistoric land use in the study area during the Colonial and Sedentary periods.

The primary goal of the study was to delimit the kind, extent, and temporal duration of aboriginal land use in the Adobe 4 project area. Those findings were then related to more general questions concerning possible relationships between the Hohokam core area and the northern peripheral zone.

Five archaeological sites and 26 field loci were investigated. These include one small habitation unit, a ground stone quarry, a chipped stone quarry, a 300,000 square meter administrative site area which yielded evidence of both chipped stone procurement and generalized exploitation adjacent to riparian zones, an agricultural site (located north of the project area), and 26 small, surface lithic scatters. A possible canal segment, a check dam, and several small, dry-laid stone masonry rooms of unknown age were also located in the study area. Evidence of ground stone manufacture and quarrying activities in the Adobe 4 area constitute the first clear- cut indications of this undoubtedly important (but overlooked) economic activity to be discovered in south-central Arizona.

This investigation employed a multidisciplinary approach. In addition to archaeological investigations, an extensive consideration of the paleohydrology of Skunk Creek was undertaken, as were studies concerning modern vegetation in the project area, and the analysis of macrofloral, faunal, and pollen remains, and of a cremation from the habitation site.

A consideration of radiocarbon, archaeomagnetic and comparative archaeological data suggests that prehistoric use of the Adobe 4 area occurred primarily between A.D. 800 and 1100+. During that time period, Skunk Creek sustained seasonal flow during late winter, spring, and occasionally part of the summer. This contrasts sharply with its ephemeral nature today and helps to explain how prehistoric groups could have survived in the northern Hohokam peripheral zone. Evidence from the Adobe 4 area appears to fit a general model which postulates the existence of an extensive pre-Classic Hohokam interaction sphere based on economic ties between the core and peripheral areas.

美国陆军工兵团（U.S. Army Corps of Engineers）计划在亚利桑那州凤凰城北部的臭鼬溪（Skunk Creek）修建防洪大坝，Adobe 4考古缓解项目即在该大坝选址区域开展。项目区域占地约750公顷，地处盐河（Salt River）以北30公里处，属于霍霍坎文化（Hohokam）北部边缘地带。本研究旨在呈现该研究区域内殖民时期与定居时期的史前土地利用相关信息。

本研究的核心目标是明确Adobe 4项目区域内原住民土地利用的类型、范围与持续时长，并将研究结果与更宏观的问题相联系——即霍霍坎文化核心区域与北部边缘地带之间可能存在的关联。

本次调查共探明5处考古遗址与26处野外遗迹点，具体包括1处小型居住单元、1处磨制石器采石场、1处打制石器采石场、一处占地30万平方米的行政遗址区域（该区域出土了打制石器原料获取与河岸带周边广义资源开发的相关证据）、一处位于项目区域以北的农业遗址，以及26处小型地表石器散布点。研究区域内还发现了一段疑似运河的遗存、一处拦沙坝，以及数座年代不明的小型干砌石屋。Adobe 4区域内出土的磨制石器制作与采石活动证据，是亚利桑那州中南部地区首次明确发现的此类虽重要却长期被忽视的经济活动遗存。

本次调查采用多学科研究方法：除考古学调查外，团队还对臭鼬溪的古水文状况开展了全面研究，同时对项目区域内的现代植被进行了调查，并对大植物遗存、动物遗存、花粉标本以及居住遗址出土的一处火葬遗存进行了分析。

对放射性碳测年、考古地磁数据以及对比考古学资料的综合分析表明，Adobe 4区域的史前人类活动主要集中于公元800年至1100年及以后时段。在这一时期，臭鼬溪在冬末、春季乃至夏季部分时段存在季节性径流，这与如今臭鼬溪作为间歇河的状态形成鲜明对比，也为解释史前人群何以在霍霍坎文化北部边缘地带存续提供了依据。Adobe 4区域的相关证据，与“霍霍坎文化前古典时期存在以核心区与边缘区经济联系为基础的广泛互动圈”的通用模型高度契合。