Human Occupation of the Bighorn Mountains

在国家科学基金会的资助下，罗伯特·凯利博士将研究怀俄明州西北部洞穴和避难所中的晚更新世沉积物。人类殖民北美的最早确凿证据可以追溯到大约13,200年前的更新世晚期。然而，与后来的北美人不同的是，该大陆最早的居民似乎很少使用洞穴和避难所。在他们的殖民模型中，罗伯特·凯利和劳伦斯·托德(1988)认为，这表明殖民者没有使用“稀有的”景观元素，因为它们是北美快速殖民的一部分。然而，在12,000年前的洞穴和避难所中很少出现这种情况，这可能是一个抽样问题(例如，没有挖掘到足够深的深度)，或者是避难所挖掘的结果(例如，目前可以观察到的避难所在更新世晚期不能居住)。理解早期职业是多么罕见，对于理解它们为什么如此罕见至关重要。对全美各地数据的分析表明，早期在洞穴和避难所居住的情况确实很少见，=11%的地点拥有适当年龄的矿藏。使用主要在怀俄明州Bighorn MTS收集的现场数据，该项目将对洞穴和避石场中的12,000-13,500 BP沉积物进行充分采样，确定挖掘生物学在限制是否使用避难所方面的作用，并确定11%的入住率是否适用于该地区。该项目调查了怀俄明州大角山150个数据库中的一系列避难所；目前，其中只有10-11个避难所证明渗透到了12,000年前的沉积物中，只有2-3个避难所有证据表明在那个时间范围内有人使用过。将挖掘出30个避难所的样本，这些避难所有12,000-13,500年的历史，在更新世末还可以居住。该项目主要是重新调查以前挖掘的避难所，通过AMS放射性碳和光激发发光(OSL)测年重新确定其地层剖面，以避免不必要地挖掘后来的矿藏。在两名地质考古学家的协助下，该项目将收集与评估每个避难所的墓葬和古环境历史有关的数据。将在新的掩体中进行测试挖掘，以确保采集足够的样本，以及不同基岩类型和环境(例如，石灰岩与砂岩；高海拔与低海拔)中的掩体样本。智力价值一旦完成，该项目将：(A)首次确定特定地区更新世晚期居住在避难所的频率；(B)评估样本偏差和避难所分类对更新世晚期洞穴和避难所栖息的稀少证据的可能性；以及(C)提供数据，以评估用于支持Kelly/Todd晚更新世殖民模式的证据。更广泛的影响这个项目(1)加强了怀俄明大学在古印第安人考古学方面的博士课程的培训，并加强了国际合作协议(一名俄罗斯学生在2005年得到了资助)；此外，一名高中生在2006年参与了该项目(2)为其他研究项目汇编了关于大角兽避难所考古记录的信息；(3)提供了帮助评估OSL年代测定的数据；(3)导致了对以前挖掘的遗址的报告/分析；(4)证明了重新检查以前挖掘的遗址/收藏品可以有很大的回报；以及(5)帮助了公共教育；对于其中一个遗址，建造了一个小博物馆案例，描绘了研究的结果；现在，它被陈列在属于该遗址土地所有者的牧场上的洛杉矶边缘青年营地。

With National Science Foundation funding, Dr. Robert Kelly will investigate late Pleistocene deposits in caves and rockshelters in northwestern Wyoming. The earliest definitive evidence of human colonization of the North America dates to about 13,200 years ago, the terminal Pleistocene. Unlike later peoples of North America, however, the earliest inhabitants of the continent seem to have rarely used caves and rockshelters. In their colonization model, Robert Kelly and Lawrence Todd (1988) argued that this indicated that the colonizers did not use "rare" landscape elements because they were part of a rapid colonization of North America. However, infrequent occurrence of occupations in caves and rockshelters prior to 12,000 years ago could be a sampling problem (e.g, failure to excavate deep enough), or a result of shelter taphonomy (e.g, shelters that are currently observable were uninhabitable in the late Pleistocene). Understanding how rare the early occupations are is essential to understanding why they are rare. Analysis of data from across the U.S. suggests that early occupations in caves and rockshelters are indeed rare, = 11% of sites with appropriately-aged deposits. Using field data gathered primarily in Wyoming's Bighorn Mts, this projects will adequately sample 12,000-13,500 BP deposits in caves and rockshelters, determine the role of taphonomy in conditioning whether shelters were used, and determine whether the 11% occupancy rate holds true for this region or not. This project investigates a series of shelters from a database of 150 in Wyoming's Bighorn Mountains; currently, only 10-11 of these demonstrate penetration into pre-12,000 year old sediments, and only 2-3 bear evidence of human use in that time range. A sample of 30 shelters with 12,000 - 13,500 year old deposits and that were habitable at the end of Pleistocene will be excavated. The project is primarily re-investigating previously excavated shelters, redating their stratigraphic profiles through AMS radiocarbon and Optically Stimulated Luminescence (OSL) dating to avoid unnecessary excavation of later deposits. With the assistance of two geoarchaeologists the project will collect data relevant to evaluating each shelter's taphonomic and paleoenvironmental history. Test excavations will be conducted in new shelters to ensure acquisition of an adequate sample, as well as an adequate sample of shelters in different bedrock types and settings (e.g. limestone vs. sandstone; high vs. low elevation). Intellectual MeritsOnce completed, this project will (a) establish for the first time, the frequency of terminal Pleistocene occupations in shelters in a specific region; (b) evaluate the probability that sample bias and shelter taphonomy are responsible for the sparse evidence of terminal Pleistocene habitation of caves and rockshelters; and (c) provide data to evaluate one piece of evidence used to support the Kelly/Todd late Pleistocene colonization model. Broader ImpactsThis project (1) enhances training in the University of Wyoming's doctoral program in paleoindian archaeology and enhances international cooperative agreements (a Russian student was sponsored in 2005); in addition, a high school student participated in the project in 2006 (2) compiles information on the archaeological record of Bighorn shelters for other research projects; (3) provides data to help evaluate the utility of OSL dating; (3) is leading to reports/analyses on previously-excavated sites that have not been reported; (4) demonstrates that re-examining previously-excavated sites/collections can have large payoffs; and (5) has helped with public education; for one site, a small museum case was constructed depicting the results of the research; this is now on display at a camp for Los Angeles youth-at-risk on the ranch belonging to the site's landowner.