Peter E. Wigand

The North American Great Basin: A Sensitive Indicator of Climatic Change

Climatic change has become a major scientific and political issue during the past decade. Articles concerning global warming due to the greenhouse effect and ozone depletion from industrial chemicals are common in the news media and scientific literature. As stated by Schneider (1989), “the intense heat, forest fires, and drought of the summer of 1988 and the observation that the 1980s are the warmest decade on record have ignited an explosion of media, public, and governmental concern that the long-debated global warming has arrived”.

Southwestern North America

The greater American Southwest of the North American continent is a region typified by great topographic diversity formed by a complex interaction of numerous continental plates. Driven by the interaction of climate, topography, and distance from the Pacific Ocean to the west and north, and from the Gulf of Mexico to the southwest, vegetation communities as diverse as desert shrub, chaparral and semiarid woodlands, oak and montane conifer forests, subalpine woodlands and grasslands, as well as tundra can be found within relatively short distances of each other. During the Holocene the region has been characterized by dynamic climate and vegetation change that has been amplified by topography, that has served both to impede the flow of moisture-laden storms from the Pacific to the west and to channel monsoonal storms northward from the Gulf of California and the Gulf of Mexico. Climatically, the region has been influenced by three weather patterns characterized by differences in seasonal distribution of rainfall and temperature. Displacement of winter and summer storm tracks, and variations in the penetration of summer monsoon have all been affected by the realignment of these weather patterns through time. Movements of these systems during the Holocene have had a dynamic affect upon both local and regional climates, and is reflected in the palaeoecological proxy record by changes in hydrology, erosion and deposition processes, as well as in vegetation. It is the pollen and plant macrofossil records of the region that provide some of the basic information for reconstructing this climate history.

Reassessment of Radiocarbon Age Determinations for the Munkers Creek Phase

Abstract The Munkers Creek phase was initially defined using cultural assemblages from the William Young site in the north central Flint Hills of Kansas. Radiocarbon ages from the type site are suspect due to extremely large standard deviations on all but one date and because of stratigraphic inconsistencies. Recently, samples of curated wood charcoal from stratigraphically separate cultural levels at the William Young site were submitted for dating in an attempt to better ascertain the age range for the site’s Munkers Creek phase cultural components. The new radiocarbon ages are more precise and are stratigraphically consistent. These new assays and all other contemporaneous radiocarbon dates from other Munkers Creek phase contexts have an average age of 5259 ± 26 B.P. with a three sigma range of 5180-5338 B.P. The sum of the areas under the polynomial curves using decadal means indicates the mean to be ∼5240 B.P. The new dates and this statistical analysis have helped to refine our understanding of the temporal placement of the Munkers Creek phase in the Kansas prehistoric cultural sequence.

Application of Dendrochronology to Historical Charcoal-Production Sites in the Great Basin, United States

During the Comstock mining era of the late 1800s, forested lands in the North American Great Basin were used for charcoal production to fuel mining smelters and related industries. Archaeological studies within or near mining districts include assessments of charcoal-production sites when such remnant features are present. Minimal historical documentation exists for individual production sites, and so the science of dendrochronology (tree-ring dating) is used to provide calendar dates and other information on the nature of historical activity within forests and woodlands. A synthesis of the dendrochronological approach to historical charcoal-production investigation is presented in the context of four recent studies, including a comprehensive strategy, new processing techniques, and unique results. This approach provides charcoal-production archaeologists with precise temporal and spatial data that are applied to questions such as patterns and timing of deforestation, or differences in technology and practices among immigrant laborers.