North-central Kansas Research Articles

Development and Forcing of the Rear Inflow Jet in a Rapidly Developing and Decaying Squall Line during BAMEX

Abstract This study examines the development, structure, and forcing of the rear inflow jet (RIJ) through the life cycle of a small, short-lived squall line over north-central Kansas on 29 June 2003. The analyses were developed from airborne quad-Doppler tail radar data from the NOAA and NRL P-3 aircraft, obtained over a 2-h period encompassing the formation, development, and decay of the squall line during the Bow Echo and Mesoscale Convective Vortex Experiment (BAMEX). The strengthening of the system-relative rear inflow to 17 m s−1 was concurrent with the formation of a bow echo, an increased dynamic pressure gradient beneath the rearward-tilted updraft, and two counterrotating vortices at either end of the bow. The later weakening of the RIJ to 8 m s−1 was concurrent with the weakening of the bow, a decreased dynamic pressure gradient at midlevels behind the bow, and the weakening and spreading of the vortices. In a modeling study, Weisman quantified the forcing mechanisms responsible for the development of an RIJ. This present study is the first to quantitatively analyze these mechanisms using observational data. The forcing for the horizontal rear inflow was analyzed at different stages of system evolution by evaluating the contributions of four forcing mechanisms: 1) the horizontal pressure gradient resulting from the vertical buoyancy distribution (δPB), 2) the dynamic pressure gradient induced by the circulation between the vortices (δPV), 3) the dynamic irrotational pressure gradient (δPI), and 4) the background synoptic-scale dynamic pressure gradient (δPS). During the formative stage of the bow, δPI was the strongest forcing mechanism, contributing 50% to the rear inflow. However, during the mature and weakening stages, δPI switched signs and opposed the rear inflow while the combination of δPB and δPV accounted for at least 70% of the rear inflow. The δPS forced 4%–25% of the rear inflow throughout the system evolution.

A Late Prehistoric Bison Processing Camp in the Central Plains: Montana Creek East (14JW46)

Bison utilization during the Late Prehistoric period in the central Plains varied from the diffuse pattern that characterizes the Central Plains tradition to the focal pattern of the westernmost Oneota. Both patterns are represented at sites in the Lovewell locality on White Rock Creek, a tributary of the lower Republican River in north-central Kansas. Intensive bison exploitation is also represented at the Montana Creek East (14JW46) site within this locality. Abundant faunal remains indicative of marrow and bone grease processing are associated with the varied, if modest, lithic and ceramic assemblages. These do not suggest use by Oneota or Central Plains tradition peoples although a date fits the Late Prehistoric period. A buried Plains Woodland component, previously undocumented at Lovewell, indicates earlier evidence of bison hunting. Together the remains at this and certain other sites at Lovewell indicate extensive use of bison by different groups.

Assessing the multi-resolution information content of remotely sensed variables and elevation for evapotranspiration in a tall-grass prairie environment

Understanding the spatial scaling behavior of evapotranspiration and its relation to controlling factors on the land surface is necessary to accurately estimate regional water cycling. We propose a method for ascertaining this scaling behavior via a combination of wavelet multi-resolution analysis and information theory metrics. Using a physically-based modeling framework, we are able to compute spatially distributed latent heat fluxes over the tall-grass prairie in North-central Kansas for August 8, 2005. Comparison with three eddy-covariance stations and a large aperture scintillometer demonstrates good agreement, and thus give confidence in the modeled fluxes. Results indicate that the spatial variability in radiometric temperature (a proxy for soil moisture) most closely controls the spatial variability in evapotranspiration. Small scale variability in the water flux can be ascribed to the small scale spatial variance in the fractional vegetation. In addition, correlation analysis indicates general scale invariance and that low spatial resolution data may be adequate for accurately determining water cycling in prairie ecosystems.

Presence of the Evening bat (Nycticeius humeralis) in westernmost Kansas

The evening bat, Nycticeius humeralis, is an austral species (Armstrong, Choate, and Jones 1986) that ranges from the southeastern United States north to the southern Great Lakes region and west to the central Great Plains (Watkins 1972). In Kansas, the species was known from just four counties (Clay, Douglas, Jewell, and Johnson) in the northeast when Jones, Fleharty, and Dunnigan (1967) reviewed the distributional status of bats in the state. Birney and Rising (1968) subsequently reported specimens of the evening bat from Franklin and Ford counties, the latter in southwestern Kansas, and Kunz, Choate, and George (1980) reported specimens from Barber and Comanche counties in south-central Kansas. Sparks and Choate (2000) added more than a dozen counties, most in north-central Kansas, to the known range of the species in the state and opined that this tree-dwelling species, which previously was rare at the western limit of its range, was becoming increasingly common in riparian corridors. They concluded that the lack of forested habitats in much of western Kansas in the past possibly restricted the range of the evening bat to the eastern twothirds of the state (Sparks and Choate 2000), but that growth of forested habitats along watercourses was enabling this species to expand westward.

New reservoir model from an old oil field: Garfield conglomerate pool, Pawnee County, Kansas

Garfield field, an old (1948) stratigraphic trap in central Kansas, produced 10 million bbl of oil from Cherokee (Desmoinesian, Pennsylvanian) conglomerate reservoirs and from Mississippian carbonate and sandstone reservoirs. The primary reservoir rock at Garfield conglomerate pool is the Pennsylvanian basal conglomerate (PBC), unique in that it accumulated as an unstratified alluvial-fan deposit, in a subtle structural depression that may be coincident with a microplate boundary. Each of these conditions is uncommon in the northern Mid-continent. The PBC at Garfield pool is composed of pebbles, cobbles, and boulders of reworked Mississippian chert and limestone in a matrix of porous, fine-grained sandstone and sandy shale. Microporosity in the chert cobbles has access to the borehole through the porous sandstone matrix. The sandstone matrix was the product of reworking of the original shaly sand matrix and older sandstones from the substrate during short-term Desmoinesian marine transgressions of the alluvial-fan surface. Ultimately, Marmaton transgressive onlap smoothed and buried the fan surface. A near-modern alluvial fan at Rocky Flats in central Colorado provides an ideal analog for the PBC deposit at Garfield pool. The Rocky Flats fan is nearly identical in scale, areal distribution, and thickness, and its constituents are remarkably similar to conglomerate zones, which produce hydrocarbons at Garfield pool. Future exploration in north-central Kansas and southern Nebraska should focus on the occurrence of conglomerate deposits in similar depositional settings where coincident with structural depressions.

An evaluation of selenium concentrations in water, sediment, invertebrates, and fish from the Solomon River Basin

The Solomon River Basin is located in north-central Kansas in an area underlain by marine geologic shales. Selenium is an indigenous constituent of these shales and is readily leached into the surrounding groundwater. Portions of the Basin are irrigated primarily through the pumping of selenium-contaminated groundwater from wells onto fields in agricultural production. Water, sediment, macroinvertebrates, and fish were collected from various sites in the Basin in 1998 and analyzed for selenium. Selenium concentrations were analyzed spatially and temporally and compared to reported selenium toxic effect thresholds for specific ecosystem components: water, sediments, food-chain organisms, and wholebody fish. A selenium aquatic hazard assessment for the Basin was determined based on protocol established by Lemly. Throughout the Basin, water, macroinvertebrate, and whole fish samples exceeded levels suspected of causing reproductive impairment in fish. Population structures of several fish species implied that successful reproduction was occurring; however, the influence of immigration of fish from low-selenium habitats could not be discounted. Site-specific fish reproduction studies are needed to determine the true impact of selenium on fishery resources in the Basin.

One Hundred Years of Echinacea angustifolia Harvest in the Smoky Hills sof Kansas, USA

Abstract Echinacea angustifolia DC. (Asteraceae) is a major North American medicinal plant that has been harvested commercially in north-central Kansas for 100 years, making it one of the longest documented histories of large-scale commercial use of a native North American medicinal herb. We have compiled historical market data and relate it to harvest pressure on wild Echinacea populations. Interviews with local harvesters describe harvesting methods and demonstrate the species' resilience. Conservation measures for E. angustifolia also should address the other threats faced by the species and may include restoration and management of its mixed-grass prairie habitat and protection by private landowners.

Regional disconformities in Turonian and Coniacian (Upper Cretaceous) strata in Colorado, Wyoming, and adjoining states biochronological evidence

Siliciclastic and calcareous sedimentary rocks of early Late Cretaceous age in the Western Interior of the United States have been assigned to, in ascending order, the Graneros Shale, Greenhorn Formation, Carlile Shale, Niobrara Formation, and their lateral equivalents (including members of the Frontier Formation and overlying formations). This sequence of formations was deposited intermittently within and near an epicontinental seaway during the Cenomanian, Turonian, and Coniacian stages of the Cretaceous. It encloses three conspicuous and widespread disconformities that reflect regional marine regressions and transgressions as well as moderate tectonism. The disconformities and associated lacunae occupy three large areas within Wyoming, Colorado, and adjoining states. In parts of that region, as in northwestern Wyoming, a lacuna can represent more than one period of erosion and more than a single disconformity. Evidence for these disconformities was obtained from about 175 collections of molluscan fossils and from sedimentological studies of outcrops and borehole logs, supplemented by previously published data. The oldest of the three disconformities, within the Frontier Formation and partial age-equivalents (including the Carlile Shale), separates Cenomanian or lower Turonian beds from middle Turonian beds in central and western Wyoming, northwestern Colorado, and adjoining areas of Montana and Utah. In parts of that region, the maximum duration of the associated lacuna is about 3 m.y. Erosion of the region in the late early Turonian was associated with a marine regression and transgression as well as mild local tectonism. The area where strata underlying the unconformity are oldest is partly overlain by the youngest of the succeeding transgressive beds. These youngest overlying beds presumably were deposited in an uplifted area where the eroded surface had a slightly higher elevation. A younger disconformity, within the Frontier Formation and lateral equivalents, separates upper Cenomanian or lower or middle Turonian strata from middle or upper Turonian strata in central and eastern Wyoming, southwestern South Dakota, western Nebraska, and central and eastern Colorado. Locally in that region, the duration of the lacuna is as much as 5 m.y. The oldest beds underlying this contact are of late Cenomanian age and are distributed in north-central and southeastern Wyoming and in north-central Colorado, where the erosional surface was affected probably by slight uplifts and by fluvial drainage systems. In that region, the oldest beds are partly overlain by the youngest (late Turonian) of the transgressive strata. The areal distribution of the younger overlying beds in central Wyoming could indicate a westward migration of marine prodelta environments during the late Turonian. At the youngest of the three disconformities, strata of middle or late Turonian ages in the Carlile Shale and lateral equivalents are overlain by upper Turonian or lower or middle Coniacian beds of the basal Niobrara Formation in Wyoming, Colorado, Nebraska, and parts of adjoining states. The maximum duration of the associated lacuna is more than 4 m.y. in northwesternmost Wyoming and northeasternmost Nebraska. Beds underlying this disconformity are oldest (early middle Turonian) in northwestern Wyoming, northeasternmost Nebraska, and possibly elsewhere in Nebraska, which apparently were areas of comparatively higher elevation and greater truncation. The underlying beds are youngest in a northeast-trending area that extends at least from eastern Utah to northeastern Wyoming. This area presumably was uplifted less than adjoining areas possibly in the late Turonian. Strata overlying this disconformity are oldest in northeastern New Mexico and much of Colorado and are youngest in northeastern Utah, northwestern and east-central Wyoming, north-central Kansas, and northeastern Nebraska, which indicates a marine transgression that progressed mainly northward. Most of the ages used for the following calculations are estimates; consequently the resulting quantitative interpretations are speculative. The duration of the lacuna between the uppermost Carlile and the basal Niobrara increased northwestward from about 0.8 m.y. in south-central Colorado to about 4.3 m.y. in northwesternmost Wyoming. It also increased northeastward from 0.8 m.y. in Colorado to about 5.1 m.y. in northeastern Nebraska. Ages of basal beds of the Niobrara decrease northwestward from about 89.3 Ma in southeastern Colorado and northeastern New Mexico to about 88.7 Ma in northwesternmost Wyoming. Apparently, the Niobrara sea transgressed northwestward about 500 mi (805 km) from southeastern Colorado to northwesternmost Wyoming in about 0.6 m.y. Ages of the basal Niobrara also decrease toward the northeast, from 89.3 Ma in southeastern Colorado to 87.6 Ma in northeasternmost Nebraska. The Niobrara sea in that region, where chronologic data are notably sparse, possibly transgressed more than 480 mi (772 km) in about 1.7 m.y.

Jiternice and Kolache: Food and identity in Wilson, Kansas

A small town in north-central Kansas uses its ethnically Czech heritage, especially traditionally Czech food products, as a way to maintain personal and social identity and to encourage heritage tourism as a means of economic development. Wilson, Kansas, is a town with a significant proportion of its population that is ethnically Czech. The town is attempting to use this ethnic background and its historical nature to deal with economic and demographic problems caused by its location away from major transportation infrastructures and lack of large-scale employers. The residents are using elements of Czech ethnicity and historical identity to create useful social and personal identities in the face of the challenges created by their unique situation. We focus on the primary areas of the food served at the After-Harvest Czech Festival, the Midland Hotel, analysis of local cookbooks featuring Czech cooking, and changing meal patterns among local residents in order to examine the nature of the changing identity of the residents and the town. The four areas examined show the difference between the ways that ethnicity is performed in the public and private space and the way in which the Midland Hotel functions as a metaphor for the larger changes that are affecting the community.

Homogenization of fish faunas in two categories of streams in a single basin in Kansas and the choice of similarity coefficients

The process of biotic homogenization represents an increased similarity among communities in their taxonomic, genetic, or functional attributes (Olden et al. 2004) through the loss of unique elements of native communities and the addition of widespread, nonnative elements (McKinney and Lockwood 1999). Thus, homogenization can result from introductions, extirpations, or both (Olden and Poff 2003; Olden and Poff 2004). Most assessments of the homogenization of fish faunas in streams have focused on comparisons of communities among basins, ecoregions, or states (Duncan and Lockwood 2001; Marchetti et al. 2001; Carlson and Daniels 2004). However, Scott and Helfman (2001) compared fish faunas in highland and lowland streams in the southeastern USA and discussed the importance of assessments at these smaller scales. Streams in western Kansas and their communities have undergone substantial changes since the state was established in 1861 (Cross and Moss 1987; Bergman et al. 2000). We used information summarized in a study on changes in the fish faunas of the Solomon River basin in north-central Kansas (Eberle et al. 2002) to assess the degree of homogenization that might have occurred between faunas characteristic of two general types of streams in a single basin in western Kansas.

Observations of foraging on taproots of invasive thistles by prairie voles

Prairie voles (Microtus ochrogaster) feed primarily on leaves and stems of forbs and grasses and to a lesser extent on plant roots and seeds, and arthropods (Fleharty and Olson 1969; Kaufman and Bixler 1995; Menhusen 1963; Zimmerman 1965). As these investigators have noted, the species eaten by prairie voles include grasses such as big bluestem (Andropogon gerardii), Indiangrass (Sorghastrum nutans), and Kentucky bluegrass (Poa pratensis), and forbs such as fireweed (Kochia scoparia), curly dock (Rumex crispus), and alfalfa (Medicago sativa). As part of our interest in the mammals of the mixed-grass prairie region of north-central Kansas, we continue to record natural history observations made in native and anthropogenic habitats. Herein, we report an unusual observation of prairie voles foraging on the taproots of invasive thistles, both musk thistle (Carduus nutans) and bull thistle (Cirsium vulgare).

Sources of Sr and implications for weathering of limestone under tallgrass prairie, northeastern Kansas

Grasslands of north-central Kansas are underlain by carbonate aquifers and shale aquitards. Chemical weathering rates in carbonates are poorly known, and, because large areas are underlain by these rocks, solute fluxes are important to estimating global weathering rates. Grasslands exist where the amount of precipitation is extremely variable, both within and between years, so studies in grasslands must account for changes in weathering that accompany changes in precipitation. This study: (1) identifies phases that dominate chemical fluxes at Konza Prairie Biological Station (KPBS) and Long-Term Ecological Research Site, and (2) addresses the impact of variable precipitation on mineral weathering. The study site is a remnant tallgrass prairie in the central USA, representing baseline weathering in a mid-temperate climate grassland. Groundwater chemistry and hydrology in the 1.2 km 2 watershed used for this study suggest close connections between groundwater and surface water. Water levels fluctuate seasonally. High water levels coincide with periods of precipitation plus low evapotranspiration rather than during precipitation peaks during the growing season. Precipitation is concentrated before recharging aquifers, suggesting an as yet unquantified residence time in the thin soils. Groundwater and surface water are oversaturated with respect to calcite within limitations of available data. Water is more dilute in more permeable aquifers, and water from one aquifer (Morrill) is indistinguishable from surface water. Cations other than Ca co-vary with each other, especially Sr and Mg. Potassium and Si co-vary in all aquifers and surface water, and increases in concentrations of these elements are the best indicators of silicate weathering at this study site. Silicate-weathering indices correlate inversely to aquifer hydraulic conductivity. 87Sr/ 86Sr in water ranges from 0.70838 to 0.70901, and it decreases with increasing Sr concentration and with increasing silicate-weathering index. Carbonate extracted from aquifer materials, shales, soil, and tufa has Sr ranging from about 240 (soil) to 880 ppm (Paleozoic limestone). 87Sr/ 86Sr ranges from 0.70834 ± 0.00006 (limestone) to 0.70904 ± 0.00019 (soil). In all cases, 87Sr/ 86Sr of aquifer limestone is lower than 87Sr/ 86Sr of groundwater, indicating a phase in addition to aquifer carbonate is contributing solutes to water. Aquifer recharge controls weathering: during periods of reduced recharge, increased residence time increases the total amount of all phases dissolved. Mixing analysis using 87Sr/ 86Sr shows that two end members are sufficient to explain sources of dissolved Sr. It is proposed that the less radiogenic end member is a solution derived from dissolving aquifer material; longer residence time increases its contribution. The more radiogenic end member solution probably results from reaction with soil carbonate or eolian dust. This solution dominates solute flux in all but the least permeable aquifer and demonstrates the importance that land-surface and soil-zone reactions have on groundwater chemistry in a carbonate terrain.

BERRIOCHLOA GABELI AND BERRIOCHLOA HULETTI (GRAMINEAE: STIPEAE), TWO NEW GRASS SPECIES FROM THE LATE MIOCENE ASH HOLLOW FORMATION OF NEBRASKA AND KANSAS

Berriochloa gabeli n. sp. and Berriochloa huletti n. sp. are described from fossil anthoecia (husks) recovered in late Miocene (Ash Hollow Formation) sediments in central Nebraska and central and western Kansas. Comparisons with other known fossil and living grasses suggest relationships with members of the grass tribe Stipeae and previously described B. intermedia Elias, 1942 from Ash Hollow deposits in north-central Kansas. Berriochloa gabeli and B. huletti were recovered in direct association with, or in the close vicinity, of rich biotas that provide evidence of widespread, probably treeless, grasslands with adjacent moist riparian habitats along streams or around temporary pools of water during deposition. Fossil vertebrates associated with the grasses at some sites suggest that the age of B. gabeli and B. huletti is early to middle Hemphillian.

White Rock Oneota Chipped Stone Tools

A standardized approach to descriptive analysis of chipped stone artifacts from the White Rock site (14JW1) in north-central Kansas allows comparison with Oneota lithic assemblages. These comparisons reinforce the interpretation of the White Rock phase as the remains of a late prehistoric Oneota population in the Central Plains. White Rock peoples made tool forms (e.g., small triangular points) similar to those recovered from Oneota sites in the Midwest. Informal tools are well represented, reflecting an Oneota lithic technology. Despite continuity in chipped stone tool production, regional adaptation is evident in the selection of lithic raw materials from the Central Plains, production of blades and blade tools, and an abundance of scrapers. The latter, along with beveled knives, reveals extensive processing of bison hides and meat, a reflection of Oneota adaptation to the Plains.

EFFECT OF BODY SIZE ON REPRODUCTIVE CHARACTERISTICS OF THE NORTHERN GRASSHOPPER MOUSE IN NORTH-CENTRAL KANSAS

Northern grasshopper mice (Onychomys leucogaster) were sampled periodically from June 1977 to November 1986 in the mixed-grass prairie region of north-central Kansas. Necropsies were performed on 175 mice to assess number of pregnancies and litter size for females and testis size for males. Fourteen of 87 females were pregnant with the earliest and latest dates of captures of pregnant females on 22 March and 18 August, respectively. The proportion of pregnant females peaked during May–June. The average number of fetuses was 4.0 (range: 2 to 5), and number of fetuses was correlated positively with body length of the mother. Testes of large males (≥110 mm) increased in size from January to August, and then rapidly regressed through October, whereas smaller males either exhibited a high degree of variability in testes size or had relatively small testes throughout this period. Temporal patterns for pregnancies and testis size suggested that the reproductive cycle for northern grasshopper mice in north-central Kansas was unimodal, and reproductive activity was greatest in late spring to mid-summer.

Changes in Fish Assemblages, Solomon River Basin, Kansas: Habitat Alterations, Extirpations, and Introductions

Abstract We sampled fishes four times each year at 12 sites on the Solomon, North Fork Solomon, and South Fork Solomon rivers in north-central Kansas during 1996 and 1997. Kirwin and Webster reservoirs are located on the North Fork Solomon River and South Fork Solomon River, respectively, and Waconda Reservoir inundates the confluence of these two rivers at the head of the Solomon River. Multivariate analyses identified two fish assemblages that were related to stream discharge. One fish assemblage was associated with stream segments that had lower discharges, such as those located upstream from Kirwin and Webster reservoirs. This assemblage was characterized by equal numbers of extirpations of native species and introductions of nonnative species. The other fish assemblage was associated with the reservoirs and stream segments that had higher discharges. This assemblage was characterized by a large number of species that were introduced or had immigrated into these areas. For the basin as a whole, 32% of...

The Effects of Prairie Habitat Loss and Land-Use Changes on Loggerhead Shrike Populations in Kansas

The vast expanse of North American prairie has been reduced by at least 90% of its original area. As a result, the populations of many grassland birds are in serious decline. This study investigated Loggerhead Shrike (Lanius ludovicianus) population trends in Kansas by comparing two Breeding Bird Survey (BBS) routes (16 and 17) in north-central Kansas showing more stable shrike populations, with two BBS routes (06 and 07) in southern Kansas showing more dramatic declines during the last 30 years. With the exception of large increases in pesticide use, there have been few land-use changes the last 30 years along the two northern routes. Along the southern routes, land-use changes include large decreases in pasture, urbanization, loss of tree rows, and large increases in pesticide use.Our land-use survey showed more pasture, woodland, scattered trees and shrubs, and barbed-wire fences in the north, and more wheat, residential areas, and tree rows in the south, indicating significant differences between study areas in key habitat requirements for breeding Loggerhead Shrikes. Our two-year census of the four BBS routes showed a higher density of shrikes in the north (3.0/census) than the south (1.9/census). The habitat associated with shrikes in the north showed a greater amount of pasture and significantly more scattered trees and shrubs compared to the south, where shrike habitats were more heterogeneous and usually associated with tree rows. The nesting success in both areas was relatively low for Loggerhead Shrikes.

Evidence of evolving carbaryl resistance in western corn rootworm (Coleoptera: Chrysomelidae) in areawide-managed cornfields in north central Kansas.

Susceptibility of adult populations of the western corn rootworm, Diabrotica virgifera virgifera LeConte, to carbaryl was determined by a survey in 1996 before the implementation of an areawide management program near Scandia in north central Kansas. Subsequently, the susceptibility of western corn rootworm adults to carbaryl has been monitored throughout the program from 1997 to 2000 in both control and managed areas. In 1996, adults were highly susceptible to carbaryl with a mean LC50 value of 0.64 microg/vial. This value was comparable to those for adults collected from other regions within Kansas. However, adult susceptibility to carbaryl decreased rapidly within the managed area, where the cucurbitacin- carbaryl-based bait SLAM has been used as the primary tool to control adults in this project since 1997. In 1999, adults collected from the managed area were 9- and 20-fold less susceptible to carbaryl at the LC50 and LC90 levels, respectively, than those evaluated in 1996. In contrast, adults collected from the control area were only 2- and 3-fold less susceptible to carbaryl at the LC50 and LC90 levels, respectively, than adults evaluated in 1996. Although field adult populations of western corn rootworm were relatively low in 2000, evaluations showed trends similar to those in 1999 regarding their carbaryl susceptibility in the managed and control areas. These results provide evidence that western corn rootworm has been evolving carbaryl resistance rapidly in response to the use of SLAM in areawide-managed cornfields near Scandia.

Pottery Production at the Mugler Site (14CY1-A), A Central Plains Tradition House in North-Central Kansas

Clay processing and resource use were investigated at the Mugler site, a late prehistoric site in north-central Kansas. Seven sherds from Mugler (14CYJ-A) were thin-sectioned for petrographic analysis and three were also submitted for x-ray diffraction. Two sherds from the Steed-Kisker type site (23PLJ 3) in western Missouri were included in the petrographic analysis for comparison. Data from these analyses were compared to published data to determine which clay accumulations or deposits were the most likely sources for prehistoric potters at Mugler. Montmorillonite-rich alluvial clays were probably used for most of the vessels sampled. The preservation and size of iron mottles in the paste suggests that clays were minimally processed before vessel manufacture.

Western Oneota Obsidian: Sources and Implications

Exotic lithic raw materials provide insight into exchange relations and mobility of prehistoric populations. Toward this end, obsidian flakes from two western Oneota sites, Warne in north central Kansas and Blood Run in northwestern Iowa, were sourced using x-ray fluorescence spectrometry. With the exception of two artifacts from Warne, all were traced to parent obsidian sources in the northwestern Plains and Plateau regions. Obsidian pieces from Warne compare favorably with geologic samples from Malad, Idaho (n=4) and Obsidian Ridge, New Mexico (n=2). Trace element composition in the Blood Run flakes is congruent with sourced standards from Obsidian Cliff, Wyoming (n=5) and Bear Gulch, Idaho (n=l). The artifacts from Warne point to down-the-line acquisition during contact with groups closer to their sources to the west and south. Such contact may have occurred during bison hunting forays in those directions. The low incidence of New Mexico obsidian supports the Late Prehistoric temporal placement of the White Rock phase. The sources of obsidian from Blood Run are consistent with those of artifacts from earlier sites in Iowa, particularly those of the Middle Woodland period, and reflect the maintenance of trade relations with northern Plains groups.