A series of severe and prolonged droughts occurred throughout the Northern Hemisphere between approximately 1150 BP to 600 BP. This phenomenon is referred to as the Medieval Climatic Anomaly and has been shown to have differentially impacted various regions of the world. Previous studies have suggested causal links between the Medieval Climatic Anomaly and observed culture change. The goal of this study was to examine the Antelope Valley region of the Mojave Desert for evidence of impacts on human populations related to the Medieval Climatic Anomaly. To achieve this goal, a sample selection of archaeological sites was chosen from lands within Edwards Air Force Base. These sites represented occupations which occurred immediately before, during, and after the Medieval Climatic Anomaly. Site assemblages were analyzed and compared by cultural period, with cross-comparisons made of artefactual and ecofactual constituents. Site densities and areal extents were also examined and compared. These analyses showed the emergence of trends concurrent with the introduction of the Medieval Climatic Anomaly. The data supports the hypothesis that humans who populated the Antelope Valley region of the Mojave Desert during this period may have engaged in population aggregation, with a tethered nomadism subsistence strategy. The data also shows evidence that upon the amelioration of the environment after the Medieval Climatic Anomaly, site characteristics within the region saw a significant shift. While the evidence generated by this study does suggest a link between climatic change experienced during the Medieval Climatic Anomaly and change observed within the archaeology of the Antelope Valley, it does not suggest climate as a sole, or even primary, causal factor. Rather, the intent of this study was to identify one possible variable responsible for observed change that occurred in the region. With this in mind, the Medieval Climatic Anomaly was found to have been significant enough to have either directly or indirectly impacted the prehistoric occupants of the study region.

Prehistoric life in the Colorado Desert endured a variety of environmental extremes. Episodic flooding and shifts in the course of the Colorado River resulted in the infilling of the Salton Basin and created a large freshwater lake known as Lake Cahuilla. Settlement along the different segments of the lakeshore is considered variable and may reflect accessibility to nearby viable resources. Remains from archaeological excavations at lakeshore sites show that lacustrine resources and fishing opportunities attracted prehistoric groups to the ancient lake. How prehistoric groups organized themselves and utilized lakeshore and nearby resources offer opportunities to explore the subsistence and mobility strategies of populations living in an oscillating environmental context. Using information generated from past Cultural Resource Management projects, the current study analyzes multiple data sets to address questions of a regional scale to more fully understand the effects of cyclical Lake Cahuilla on desert inhabitants. Analysis of existing collections and their associated documentation from late prehistoric habitation sites adjacent to the northwestern maximum shoreline as well as recessional shoreline sites some 30 miles to the south provide additional information on resource availability in a changing environment. It appears that in some circumstances the northwestern lakeshore inhabitants adapted to a changing environment and maintained occupation spanning multiple lake stands. During high stands, subsistence practices focused on lacustrine resources until no longer viable and habitation sites feature specialized subsistence technology reflecting fish procurement and processing. During lake recession, at least short-term habitation was sustained and corresponded to the exploitation of specific fish and waterfowl species. This study will help us better understand the strategies employed by groups who utilized the resources of this fluctuating lacustrine environment. Examination of resource use and mobility patterns practiced by prehistoric Lake Cahuilla inhabitants allows for interpretations of the adaptations necessary for life within this desert region. Ultimately, this research is applicable to broader anthropological queries on a regional scale. The Salton Basin is positioned within a geographical region that likely experienced influence and change from the surrounding environs. Gaining a deeper understanding of the study area will ultimately aid in future research concerning environmental adaptation, exchange relations, and culture change among the neighboring regions of the Mojave and Great Basin deserts, the agricultural Southwest, adjacent mountains and coast lines, and Baja California (Schaefer and Laylander 2007:381). Additionally, an understanding of how resource availability influenced past populations can contribute to ongoing and future studies concerned with resource management in the Colorado Desert and similar xeric environments.

The use of mortar and pestles has long been associated with acorn processing in California. Based on ethnographic and archaeological evidence, groundstone was used to process a multitude of resources, including small mammals. Twenty groundstone artifacts recovered from the Rock Camp Site in the San Bernardino Mountains were analyzed for protein residues using the crossover immunological electrophoresis (CIEP) method. Using previously obtained data from the Summit Valley, a comparative analysis was done to determine if processing small mammals on groundstone was a common occurrence throughout the San Bernardino Mountain region.

In 1985 a settlement and subsistence model of seasonal round mobility was proposed by Statistical Research, Inc. This model proposed four travel routes used by the Late Prehistoric Serrano to access the higher elevation village site known as Rock Camp to gather acorns and pinyon nuts in the fall. This research investigates the proposed routes, as well as an additional route, for energy efficiency and archaeological evidence of use in prehistory. Data collection involved using experimental methods designed to gather controlled physiological data for evaluating the efficiency of traveling each route. Archaeological sites present on the travel routes and within the research area and were analyzed for elements indicative of prehistoric settlement characteristics. A combination of physiological evidence and archaeological evidence are the basis for determinations on which routes were most likely to have been used in prehistory. An analysis of the settlement model is also provided in order to provide future research with guidelines and context for evaluating sites within the region. Suggestions are provided for future studies to focus on chronology and expansion of the settlement model.

Little is known about the time depth of human occupation in the Tualatin Valley. Archaeological investigations have produced no absolute dates for the few sites tested. Projectile points collected from the Ibach and Heynderickx farms in the Tualatin Valley show similarities to early point styles from sites in the Pacific Northwest dating from 6,000 to 10,000 years ago. To determine how old the Ibach and Heynderickx sites are, the undated collections of 107 Ibach points and 119 Heynderickx points are compared to two established chronological projectile point sequences, which had been constructed using the relative dating technique of frequency seriation. These sequences are further anchored with radiocarbon dates which extend back 6,000 years. On the basis of the comparison of Ibach and Heynderickx projectile point types to the seriated point types, it is suggested that the Tualatin Valley sites evidence occupation times at least as early as 6,000 years ago and possibly earlier.

As a result of the quick rise of pXRF technology in archaeology, there are concerns regarding the reliability and validity of data output acquired from pXRF. In this study, I test the hypothesis that portable X-ray fluorescence (pXRF) spectrometry can provide reliable and valid results, using newly developed calibration curves, for the analysis of archaeological animal and human skeletal materials in prehistoric Peru to address hypotheses about ancient diet and trade. While pXRF systems may come with calibration software, the few if any standards and reference materials provided with the instrument rarely correspond to the vast array of archaeological materials capable of being analyzed by pXRF, including archaeological bone specimens. Empirical calibration curves for Ba, Ca, Fe, and Sr were created using the linear regression analysis of 19 human and animal bone standards analyzed via pXRF and ICP-MS. The results suggest the calibrations for Ca and Sr are sound, but the calibrations for Ba and Fe need to be further improved. In order to assess the reliability of pXRF (i.e. precision and accuracy), statistical analyses of 60 measurements on human bone specimens as well as on 19 human and animal bone specimens was performed in this study. The results indicate that the precision of pXRF is reliable, but additional work is needed with regard to accuracy. In contrast, the analysis of forty-four prehistoric human and animal bone specimens from varying regions in Peru were used to test the validity of pXRF. The pXRF data support the notion that pXRF is a valid technique to use in the analysis of bone specimens to address archaeological questions regarding paleodiet and possible trade interactions among individuals that reside in the highland and coastal valley regions of Peru

Sugarcane cultivation has played a key role in the development of the Caribbean since the seventeenth century A.D. The Eastern Caribbean island of Antigua in the West Indies was almost exclusively dedicated to sugarcane monoculture from the mid-1600s until its independence from Britain in 1981. This research seeks to better understand the landscape legacies left by long-term sugarcane monoculture at the site of Betty's Hope Plantation in Antigua. This study creates a 400-year simulation of crop yields using the USDA's Erosion Productivity Impact Calculator (EPIC), and evaluates the simulated trajectory of landscape change using historical information about the plantation's agricultural yield and a geoarchaeological analysis of the regional landscape. Findings suggest that some parts of Betty's Hope have experienced degradation due to long-term sugarcane monoculture, but degradation in other parts of the region may be the result of the cessation of commercial agriculture in 1972, when human investment in the highly engineered landscape ended. If these results are representative of other parts of the island, then they suggest that current erosion and degradation experienced today cannot be attributed to intensive plantation agriculture alone, but rather are part of a complex mosaic of human- environmental interactions that includes abandonment of engineered landscapes.

This research describes a large, newly-recorded archaeological site in the Upper Apalachicola River valley, northwest Florida, and a private collection of artifacts from it, as well as test excavations, three-dimensional modeling, clay/pottery sourcing through chemical analysis, and direct radiocarbon dating of ceramics to relate the site with regional archaeological chronologies and settlement patterns. A University of South Florida (USF) 2013 field school conducted excavations at the multicomponent midden on the western floodplain of the Apalachicola River called the McKinnie site (8JA1869). Students collaborated with a local collector and family members to learn about the site's history. Data from the collection and excavations show that the site was inhabited through four thousand years of prehistory, serving as a rich seasonal resource base for local people in the area starting in the Middle Archaic Period, and as a small place of occupation during the Woodland Period, until people moved out into the river valley to live in farming villages. We also investigated a series of fascinating features, stored in the private collection and excavated by USF, which may have been intentionally buried at the site up to 5500 years ago. They may be evidence of some ancient ochre processing to obtain pigments, or some other special activity.

Throughout history and prehistory, Sicily has played a key role for maritime trade in the Mediterranean. Interactions with Sicily are attested to in research for various societies throughout the Mediterranean as early as the Neolithic. However, much of this research paints Sicilian societies as passive, focusing primarily on external groups of people in a given period and their influence on the island. By ignoring the importance of the indigenous population, current research lacks a balanced approach to investigations and subsequent conclusions. This is most evident in literature pertaining to Mycenaean interactions with Sicily during the Bronze Age. Ceramic evidence and archaeometric studies can be used to reveal the impetus and scope of these interactions. This research addresses the nature of exchange in Bronze Age Sicily prior to Mycenaean influence. In addition, my research addresses apprehensions regarding the precision of portable X-ray fluorescence (pXRF) analysis on archaeological ceramics. Samples of Bronze Age ceramics from eight archaeological sites in southern Sicily were analyzed using non-destructive pXRF spectrometry. Multiple single spot and multi-spot analyses were conducted to assess the precision of the device and the non-destructive application of the technology on potentially heterogeneous materials. Findings show no significant difference in trace element composition levels with either method. Regional signatures of ceramic trace element compositions may be developed and used to assess existing exchange patterns in Bronze Age Sicily. Comparison of ceramic exchange patterns between the Early and Middle Bronze Age suggests that Sicilian populations had a strong local identity and were noticeably inter-connected prior to Aegean influence.

The Crystal River site (8CI1) is a Woodland-period (ca 1000 B.C. to A.D. 1050) mound complex located on the Gulf of Mexico in west-central Florida. Among the features at the site are four shell and sand platform mounds, two burial mounds, and an extensive shell midden. The proximity to the Gulf and the reliance on marine and brackish resources present an apparent, yet poorly understood interaction between the people of this area and their environment. I attempt to model the relationship of the occupation of Crystal River with sea level change. The analysis of 58 soil cores from across the site provided detailed stratigraphic information and AMS radiocarbon dates needed to examine anthropogenic site formation. I then compared the rates of midden deposition and monumental architecture construction with sea level and climatic periods. This research revealed that landscape modification occurred during periods of both high and low mean sea level suggesting that human-environmental interaction at Crystal River cannot be modeled by sea level alone. Further comparison showed that mound construction increased and midden deposition decreased during the Vandal Minimum indicating a possible sociopolitical transition concurrent with changing environmental conditions.