Southeast Montana Research Articles

The Paleocene Horse Creek florule, Tongue River Member of the Fort Union Formation, southeastern Montana, USA

We investigated leaf, cone and fruit impressions preserved in a siltstone deposit between coal seams in the late Paleocene Tongue River Member near Otter, southeast Montana, to assess the floristic diversity and composition. We document the presence of Taxodium based on seed cone scales as well as foliage branches and associated pollen cones, and a low-diversity angiosperm assemblage of about 15 genera dominated by Platanaceae (Platanus, Macginitiea, Macginistemon) and Cornales (Cornus, Davidia, Amersinia, Browniea), cf. Trochodendraceae (Zizyphoides, Nordenskioeldia), augmented by Aesculus, Trochodendroides, Ulmites and Porosia. Most of these genera were widespread in the Paleocene of the Northern Hemisphere. The low diversity of this florule is consistent with that of Tiffanian assemblages elsewhere in Montana and Wyoming. The leaf known as Phyllites demoresii Brown is proposed as a likely candidate to correspond with the extinct fruits called Porosia verrucosa (Lesquereux) Hickey emend. Manchester et Kodrul.

Petrophysical Tutorial, Lessons Learned, and Evaluation Workflow: A Case Study in the Power River Basin

The objective is to empower the reader and scientific community with the knowledge and specific applicable equations to then reproduce the critical rock and fluid attributes in the Powder River Basin. To then continue to unravel the basin and its potential (both conventionally and unconventionally). The overall goal is to ensure the transfer of knowledge and communication of a petrophysical workflow that can then also influence application to other basins worldwide. The Powder River Basin is in southeast Montana and northeast Wyoming and is a prolific oil and gas (hydrocarbon-prone) sedimentary basin related to the greater Rockies chain/series of hydrocarbon-bearing basins (ex. Big Horn, Greater Green River, Denver-Jules). In this study, we briefly set-up the geological background of the Powder River Basin and the importance/ relevance to then tackling subsurface petrophysical evaluation on a regional scale. Approximately, 200 wells were evaluated petrophysically by a combined deterministic and inversion-based workflow representing an effort to share best practices, approaches, and the relative trends to apply in the basin to unravel the stratigraphic hydrocarbon potential in place. An extensive workflow involving basic petrophysical approaches such as raw log applicable cutoffs and volume of clay determination are shared as well as extending knowledge and application into advanced petrophysics through geochemical property derivation and impact of those derived properties as well as bound versus free water and hydrocarbon understanding. Results of the petrophysical analysis highlight the varying properties in conventional and unconventional formations (example Niobrara). The results of how and why the petrophysical approach was calibrated and then applied are the primary efforts accomplished.

Capacitance-Resistance Model Used for Integrated Detection of Water Production

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper IPTC 19333, “Integrated Detection of Water Production in a Highly Heterogeneous and Tight Formation Using a CRM Model: A Case Study on Waterflooding Gaither Draw Unit, Wyoming, USA,” by Kailei Liu, China University of Geosciences; Xingru Wu, SPE, University of Oklahoma; and Kegang Ling, University of North Dakota, prepared for the 2019 International Petroleum Technology Conference, Beijing, 26–28 March. The paper has not been peer reviewed. Copyright 2019 International Petroleum Technology Conference. Reproduced by permission. The Gaither Draw unit is a heterogeneous tight formation with an average permeability of less than 0.1 md. After substantial water injection, there was no clear benefit of injected water for any producer. However, knowing the distribution of the injected water is critical for future well planning and quantification of injection efficiency. The objective of this study is to show how the capacitance-resistance model (CRM) was used on this field and how it validated the use of other independent methods. This paper demonstrates that integration of different sources of data in reservoir management is critical. Introduction Unlike numerical reservoir simulation, the CRM requires only the injection rates of each injector and the production rates of each producer as input to evaluate reservoir performance. The connectivity and the time constant that are estimated by fitting production rates can provide useful information about geological features and reservoir heterogeneity. With a clear understanding of reservoir heterogeneity, flow barriers and high-permeability zones can be identified. Significant reservoir heterogeneity may lead to poor sweep efficiency. These characteristic features make the CRM (the development of which is outlined in the complete paper) a unique and practical tool to investigate water-flooding projects. Basics of the CRM The root of the CRM is the governing material-balance equation stating that the mass difference in an arbitrary control volume (CV) is equal to the mass difference between injected and produced fluid passing through this CV. Then, the governing material-balance equation is combined with a linear productivity model to obtain an ordinary differential equation. The semianalytical solution of the ordinary differential equation forms the CRM. In the field case, there are often many injectors and producers, which would be a large nonlinear optimization problem in the CRM. A CRM-producer (CRMP) model can be used to reduce the number of time constants and increase computational speed. The equations contributing to such a model are provided in the complete paper. Case Study The study area is located in the Parkman reservoir, which is a part of the Powder River Basin in southeast Montana and northeast Wyoming. The Parkman Sandstone Member of the Upper Creta-ceous Mesaverde formation is the oldest sandstone member in a widespread cycle of late Cretaceous regression. The Parkman reservoir consists of multiple stacked sands 5,000 to 9,500 ft deep. There are three dominant lithologies of the Parkman reservoir. The first is pro-delta shale and siltstone, which includes very fine and well-sorted sandstone. The second is medium-grained sandstone, which lies as coarsening-upward successions mixed with siltstone. The last is silt and mudstone, which gradually changes from exhibiting carbonaceous to lignitic characteristics.

Supporting Caregiver Use of Child Restraints in Rural Communities via Interactive Virtual Presence.

When used correctly, child restraint systems (CRS) effectively reduce the risk of serious injury and death to child passengers in motor vehicle crashes. However, error rates in CRS use among caregivers are extremely high. Consultation with child passenger safety technicians (CPST) reduces misuse rates, but access to CPST is limited, particularly in rural areas. Remote consultation via interactive virtual presence (IVP) may increase access to CPST. One hundred and fifty caregivers in Southeast Montana completed remote consultation with CPST via IVP. Errors in CRS selection, installation, and child positioning were coded at baseline and postintervention in a within-subjects, pretest-posttest design. The proportion of caregivers making one or more errors in CRS selection (McNemar's test p < .001) and installation (McNemar's test p < .001), but not child positioning, significantly decreased following remote consultation. IVP is a promising mobile health (mHealth) strategy for providing remote consultation with CPST to improve rates of correct CRS use and mitigate child injury risk.

Poor Man’s Love Song

Poor Man’s Love Song Shann Ray (bio) Is there anything pureanymore? Not me,I know. But you well, yes, hell yes you arepure sweet vintage is what I hearsung in hardwood cathedrals from way back,the sound going on forever andso good to the ear, like medicine soothe my soul soft sweet pure swishpure honey money swish snap whap thwapsweet sweat rhythm deep fade swish three thunder on the mountain wherelightning strikes, so let it rainpure money swish coin cash love light that light that match so it rainsfire pure fire en fuego fuegofire on fire so every forest blazes pure true cotton cash moneycotton cash money honeyswish sweet cold cash money cotton honey, honey honey love, honey pure love pure honey love. [End Page 177] Shann Ray Shann Ray’s collection of short stories, American Masculine, received the American Book Award, the High Plains Book Award, and the Bakeless Prize. He is also the author of the debut novel American Copper; a work of political theory, Forgiveness and Power in the Age of Atrocity; and Balefire, a poetry collection. His work has appeared in McSweeney’s, Montana Quarterly, Narrative, Northwest Review, and Poetry. He spent part of his childhood on the Northern Cheyenne Reservation in southeast Montana and has lived in Alaska, Canada, and Germany. A systems psychologist focusing on the psychology of men, he now lives with his wife and three daughters in Spokane, Washington, where he teaches leadership and forgiveness studies at Gonzaga University. Copyright © 2015 University of Nebraska Press

Linking conservation actions to demography: grass height explains variation in greater sage‐grouse nest survival

Conservation success often hinges on our ability to link demography with implementable management actions to influence population growth (λ). Nest success is demonstrated to be important to λ in greater sage‐grouse Centrocercus urophasianus, an imperiled species in the North American sagebrush‐steppe. Enhancing this vital rate through management represents an opportunity to increase bird numbers inside population strongholds. We identified management for grass height as an action that can improve nest success in an analysis of sage‐grouse nests (n = 529) from a long‐term study (2003–2007) in the Powder River Basin, southeast Montana and northeast Wyoming, USA. Average grass height by study area and year varied (11.4–29.2 cm) but its positive effects on nest survival were consistent among study years and study areas that differed in absolute rates of nest success. We tested the predictive ability of models by grouping output from log‐link analyses (2004–2006) into two bins with nest success probabilities &lt; 0.45 and &gt; 0.55, and validated the relationship with additional data from 2003 and 2007. Nests with probabilities &gt; 0.55 were 1.64 (2004–2006) to 3.11 (2007) times more likely to hatch than those &lt; 0.45, except in 2003 when an early wet spring resulted in universally high grass height at nest sites (29.2 cm) and high predicted nest success (64%). The high predictive power of grass height illustrates its utility as a management tool to increase nest success within priority landscapes. Relationships suggest that managing grass height during drought may benefit sage‐grouse populations.

Low neutral genetic diversity in isolated Greater Sage-Grouse (Centrocercus urophasianus) populations in northwest Wyoming

ABSTRACT Identifying small, isolated populations is a conservation priority, not only because isolation may result in negative fitness consequences, but these populations may also harbor unique genetic diversity. The Greater Sage-Grouse (Centrocercus urophasianus) is a widespread obligate species of the sagebrush biome in western North America that has experienced range-wide contraction over the past century. To prevent local extirpation, efforts have been made to identify isolated populations. Here, we analyzed 16 microsatellite loci from 300 Greater Sage-Grouse individuals to assess genetic structure among populations in Wyoming and southeast Montana, particularly with the Jackson Hole and Gros Ventre populations in northwest Wyoming. Four genetic clusters were observed with Pinedale (central-west) and Casper (central) populations forming a cluster, Powder River Basin (central-north) and southeast Montana forming a second cluster, and both Jackson Hole and Gros Ventre forming distinct population cluster...

The Death of Rhetoric

Poetry is about the experience of meaning as well as the meaning of experience. To read a poem is to feel one’s way into the inner workings of its language, rather than to peer through that speech to an extractable truth. It is to treat words as constitutive of meaning, not simply as reflective of it. This, to be sure, is true of all verbal acts, even the most banal, but poetry is the place where the performative, rhetorical dimensions of speech rise to supreme self-consciousness. No poem reports on an experience without casting a continual sideways glance at itself. It is this, among other things, that marks the difference between Wallace Stevens and a report on the sanitation system of southeast Montana. The early poetry of T.S. Eliot, for example, tempts us to read through its verbal density to a determinate meaning, while mischievously withholding any such semantic consolation. To write “Let us go then, you and I, / When the evening is spread out against the sky / Like a patient etherized upon a table,” as Eliot does at the opening of “The Love Song of J. Alfred Prufrock,” is to cajole the unwary reader into wondering how on earth the evening can resemble an anesthetized patient, whereas the true effect of the lines is surely to draw ironic attention to the kind of dislocated modern sensibility that could come up with such an incongruous simile in the first place. The image concerns form, not content. What matters is its rhetorical effect, not its abstractable sense. Acad. Quest. (2012) 25:546–551 DOI 10.1007/s12129-012-9318-3

Low Neutral Genetic Diversity in an Isolated Greater Sage Grouse (Centrocercus Urophasianus) Population in Northwest Wyoming

Habitat loss is well recognized as an immediate threat to biodiversity. Depending on the dispersal capabilities of the species, increased habitat fragmentation often results in reduced functional connectivity and gene flow followed by population decline and a higher likelihood of eventual extinction. Knowledge of the degree of connectivity between populations is therefore crucial for better management of small populations in a changing landscape. A small population of greater sage-grouse (Centrocercus urophasianus) exists in northwest Wyoming within the Jackson Hole valley, including Grand Teton National Park and the National Elk Refuge. To what degree the Jackson population is isolated is not known as natural dispersal barriers in the form of mountains and anthropogenic habitat fragmentation may limit the population’s connectivity to adjacent populations. Using 16 microsatellite loci and 300 greater sage-grouse samples collected throughout Wyoming and southeast Montana, significant population differentiation was found to exist among populations. Results indicated that the Jackson population was isolated relative to the other sampled populations, including Pinedale, its closest neighboring large population to the south. The one exception was a small population immediately to the east of Jackson, in which asymmetric dispersal from Jackson into Gros Ventre was detected. Both Jackson and Gros Ventre populations exhibited significantly reduced levels of neutral genetic diversity relative to other sampled populations. More work is warranted to determine the timing at which Jackson and Gros Ventre populations had become isolated and whether it was primarily due to recent habitat fragmentation or more historic processes. Due to its small population size, continual monitoring of the population is recommended with the goal of at least maintaining current population size and, if possible, increasing suitable habitat and population size to levels recorded in the past.

English

An uncommon variety of perennial mustard occurred in a topsoil stripping area at a southeast Montana coal mine. Spring Creek Coal Company is attempting to reestablish Physaria didymocarpa (Hook.) A. Gray var. lanata A. Nelson, woolly twinpod, in reclamation. This recognized variety is rated S1 in Montana (at risk, imperiled); the G5 (common, secure) global designation refers to generic Physaria didymocarpa (common twinpod), whereas T2 (less imperiled than S1, it occurs also in WY) refers to the trinomial (var. lanata). It is more of a stenotopic stress-tolerator than a competitor. In the wild, fruits aren't produced every year and empty capsules are common, hence the prospects for collecting seed appeared dim. Fifty mature plants were collected from the area permitted for mining and transplanted into five-gallon Smartpots™ with a mix of native scoria soil, manure-based compost, and commerical mycorrhizal inoculant. One year later, most were magnificent specimens bearing more and bigger fruits than seen in nature. Because seed production is naturally meager, cloning was implemented to propagate seedlings to become nursery-raised transplants. Tissue culture was easily started from seed provided by three of the original transplants. However, transplanting and acclimatizing them to commercial greenhouse conditions presented other problems. Seedling survival was just 15%. Seed collected from the initial transplants, prompted by their prodigious fruit production, yielded about 90% survival. From these two propagation methods, more than one thousand 115-ml (seven- cubic-inch) stubby cells were raised in 2008. An experimental population was planted in fall 2008 into suitable mine reclamation. Approximately 800 seedlings will be transplanted in spring 2009, this effort to be repeated in subsequent years. In addition to delicate clone roots/indurate agar, challenges include nursery rot due to the tendency to collect water at the rosette center, providing good root/soil contact when transplanting into appropriate coarse substrate, and possible herbivory. Flexibility and adaption are key elements of the revegetation program. Some lessons may guide others similarly engaged.

Primary Productivity and Precipitation-Use Efficiency in Mixed-Grass Prairie: A Comparison of Northern and Southern US Sites

Precipitation-use efficiency (PUE) is a key determinant of aboveground net primary production (ANPP). We used long-term datasets to contrast ANPP and PUE estimates between northern (southeast Montana) and southern (north Texas) mixed-grass prairies. Effects of varying amounts and temporal distribution of precipitation on PUE were examined at the Montana site, using a rainout shelter and irrigation. Results show that 1) ANPP was 21% less in Montana than Texas (188 g · m-2 vs. 237 g · m-2); 2) plant function type (PFT) composition varied between the two study locations, with cool-season perennial grasses (CSPG) dominating in Montana (52%) and warm-season perennial grasses (WSPG) dominating in Texas (47%); 3) production dynamics varied between the two sites with 90% of ANPP completed by 1 July in Montana as compared to 31 August in Texas; 4) average PUE estimates were greater in Montana (0.56 g dry matter · m-2 · mm-1 of precipitation) than Texas (0.40 g · m-2 · mm-1); and 5) contributions to PUE estimates varied among PFT and location, with CSPG estimates being greater in Montana than Texas (52% vs. 31%) and WSPG estimates being greater in Texas than Montana (47% vs. 27%). Seasonal droughts and supplemental irrigations at the Montana site substantially altered ANPP, PFT biomass composition, and PUE. Results show PUE was responsive to PFT composition relative to amount and seasonal distribution of precipitation. Therefore, one should expect changes in ANPP and PUE to occur with shifts in precipitation patterns until PFT composition becomes adjusted to the regime. La eficiencia del uso de la precipitación (PUE) es una clave determinante de la producción primaria aérea neta (ANPP). Utilizamos una base de datos para contrastar estimaciones de ANPP y PUE entre (el suroeste de Montana) y el sur de los pastizales mixtos (norte de Texas). El efecto de la variación y la cantidad en la distribución temporal de la vegetación en PUE se examinaron en el sitio de Montana, utilizando un refugio para la lluvia e irrigación. Los resultados muestran que: 1) ANPP fue 21% menor en el sitio de Montana, que en el sitio de Texas (188 g · m-2 vs. 237 g · m-2); 2) la composición de los tipos funcionales de las plantas (PFT) varía entre las dos localidades, especies de gramíneas perenes de crecimiento de invierno (CSPG) dominaron en el sitio de Montana (52%) y gramíneas perenes de crecimiento de verano (WSPG) dominaron en el sitio de Texas (47%); 3) La dinámica de la producción varía entre los dos sitios con 90% de ANPP concluido para el 1 de Julio en Montana, comparado al 31 de Agosto en Texas; 4) el promedio de la estimación de PUE fue mayor en Montana (0.56 g de materia seca · m-2 · mm-1 de precipitación) que en Texas (0.40 g · m-2 · mm-1); y 5) las contribuciones a las estimaciones de PUE varían entre PFT y la del sitio, con una estimación CSPG mayor en Montana que en Texas (52% vs. 31%) y la estimación WSPG mayor en Texas que en Montana (47% vs. 27%). Las sequias estacional y la irrigación suplementaria en el sitio de Montana significativamente altera ANPP, la composición de la biomasa de PFT, y PUE. Estos resultados demuestran que PUE fue receptivo a la composición de PFT relativo a la cantidad y la distribución estacional de la precipitación. Por lo que uno debe esperar que ocurran cambios en ANPP y PUE con modificaciones en los patrones de la precipitación hasta que la composición de PFT se ajuste al sistema.

Soil solution and exchange complex response to repeated wetting–drying with modestly saline–sodic water

Coal bed natural gas (CBNG) extraction in the Powder River (PR) Basin of Wyoming and Montana produces modestly saline-sodic wastewater, which may have electrical conductivity (EC) and sodium adsorption ratios (SAR) exceeding accepted thresholds for irrigation (EC = 3 dS m−1, SAR = 12 (mmolc l−1)1/2. As an approach to managing large volumes of CBNG-produced water, treatment processes have been developed to adjust produced water salinity and sodicity to published irrigation guidelines and legislated in-stream standards. The objective of this laboratory study was to assess acute and chronic soil solution EC and SAR responses to various wetting regimes simulating repeated flood irrigation with treated CBNG product water, followed by single rainfall events. Fifty-four soil samples from irrigated fields in southeast Montana were subjected to simulated PR water or CBNG water treated to EC and SAR values accepted as thresholds for designation of saline × sodic water, in a single wetting event, five wetting–drying events, or five wetting–drying events, followed by leaching with distilled water. Resultant saturated paste extract EC (ECe) and SAR of soils having 33% clay. Repeated wetting with PR water having EC of 1.56 dS m−1 and SAR of 4.54 led to SAR 3 dS m−1 and SAR near 12. Subsequent inundation and drainage with distilled water, simulating rainfall-quality leaching, reduced ECe and SAR more often in coarse-textured, high salt content soils than in finer-textured, lower salt content soils. Decreases in ECe upon leaching with distilled water were of greater magnitude than corresponding decreases in SAR, reinforcing supposition of sodium-induced dispersion of fine-textured soils as a consequence of rainfall following irrigation with water having salinity and sodicity levels equal to previously published thresholds.

Application of remote-sensing and ground-truth techniques in determining the effects of coalbed-methane discharge waters on soils and vegetation

The current coalbed methane (CBM) play in the Powder River Basin of northeast Wyoming and southeast Montana is the most active in the United States. Large volumes of water generated during methane production present environmental concerns because the water typically contains high levels of sodium and is generally discharged at the surface, possibly resulting in the alteration of soil properties and changes to plant biomass. This study utilizes Landsat Enhanced Thematic Mapper (ETM) data and field observations for change analysis in a region of CBM production along Spotted Horse Creek in northeast Wyoming. Hypotheses tested in this study are: (1) plant biomass increases with the addition of saline and/or sodic CBM waters; and (2) CBM waters increase soil salinity, sodicity, and pH. Results indicate the application of CBM waters at the Spotted Horse Creek study site has initially increased plant biomass in areas of CBM activity. However, the CBM waters are very high in salinity and sodicity. Soil chemistry is affected such that pH, salinity, and sodicity levels have changed to the point of making the soils slightly sodic. Presently, these levels are within the tolerance limits for most of the plants in the region but may continue to increase with the continued discharge of CBM waters.

Ekalaka, Montana small watershed data set: Precipitation, runoff, air temperature, and soil water, 1968–1980

A 12‐year (1968–1980) hydrologic database has been developed for three sets of watersheds on the frail land resource area located near Ekalaka in southeast Montana. These records contain daily maximum and minimum air temperature, precipitation, runoff, soil water measured monthly and more often during the growing season, and breakpoint precipitation and runoff for summer runoff events. These data can be accessed from the U.S. Department of Agriculture, Agricultural Research Service, Northwest Watershed Research Center, Boise, Idaho database through the anonymous ftp site ftp.nwrc.ars.usda.gov.

Tamarisk growth at the northern margin of its naturalized range in Montana, USA

Tamarisk (Tamarix spp.), an introduced shrub or small tree, has invaded riparian areas throughout the western United States. Tamarisk invasion has been studied extensively in the Southwest, but there is little information on its performance at the northern margin of its naturalized range. We measured the canopy cover, density, height and age of tamarisk and plains cottonwood (Populus deltoides) in 50 plots at 25 sites along the Bighorn, Powder, and Yellowstone rivers in southeast Montana near the northern edge of tamarisk’s western North American range. Tamarisk commonly formed thickets on open, low terraces and along over-flow channels but was less dense beneath a cottonwood canopy. Tamarisk stems routinely died back to the ground, and the oldest live stems were generally much younger than the plants. Tamarisk 30 to 40 years old in our study area usually attained heights of only 4 m or less. Height and number of live stems of tamarisk plants were 16% and 44% lower respectively under a tall cottonwood canopy. Cottonwood grows faster than tamarisk, eventually shading it and causing its decline. We believe that tamarisk will be only an understory shrub in most eastern Montana riparian forests, declining as cottonwoods form a closed canopy. Minimizing the spread of tamarisk in riparian areas in Montana can best be accomplished by managing for cottonwood.

Spatial Distribution of Soil Attributes on Reconstructed Minesoils

Mining companies and regulatory agencies need clearly defined methods by which sample data of reconstructed minesoils can be interpolated to determine the spatial distribution and suitability of minesoils for reclamation. Objectives of this study were to model spatial distributions of minesoil attributes across reconstructed landscapes at the Rosebud Mine in southeast Montana, and to evaluate geostatistical procedures that account for spatial dependence in data. Minesoils at the Rosebud Mine have been routinely sampled in an irregular pattern of 100-m sample intervals. The combined replacement depth of topsoil and subsoil material determined the depth of sampling. Topsoil and subsoil materials were analyzed separately for replacement depth, soil texture, soil pH, and electrical conductivity. Minesoil attributes in all cases were spatially independent at the 100-m sample spacing. Four soil attributes, topsoil clay content, topsoil pH, topsoil electrical conductivity, and subsoil replacement depth, were used to described the spatial relationships found in the minesoil data. Application of kriging techniques to interpolate between data points was deemed unnecessary due to the uncorrelated nature of the data and lack of reasonable fit of any semivariograms. Trend surface analysis was used to develop a model that predicts minesoil properties across the site. For topsoil clay content, pH, and electrical conductivity, a constant surface through the overall means was the best predictive model for these properties at the site. A quadratic surface was fit to replacement depth data, which exhibited a trend across the reconstructed landscape. This data set provides an example of how geostatistical techniques can be used to evaluate spatial dependence in data. In the absence of spatial dependence, more traditional satistical techniques that rely on independent data assumptions can be used, such as regression techniques.

The Use of Limited Surface Networks to Measure Mesoscale Phenomena

Abstract Large mesonetworks have successfully demonstrated coupling of surface meteorological phenomena to convective activity. It is unrealistic however, to assume that such networks will be available for wide-area operational applications. This paper examines an alternative to large mesonetworks which applies a limited number of closely spaced (10–20 km) stations to describe mesoβ, meso-γ phenomena. The techniques are applied to data from the Cooperative Convective Precipitation Experiment conducted in southeast Montana during the summer of 1981. Examples are presented for a benign day, a day having limited convective activity, and a period having a severe convective storm. Each of these periods shows distinctive trends of convergence, vorticity and total atmospheric energy. Surface convergence shows little variance during the quiescent portions of the day. Heating and convection are accompanied by increased variance of convergence and a more organized character of its time plots. The vertical component...

Petrographic Analyses of Knobloch Coal Seam (Paleocene), Powder River County, Southeastern Montana: ABSTRACT

A single core of Knobloch coal from Powder River County, southeast Montana, was drilled to obtain samples for coal quality studies. The coal occurs in the lower Tongue River Member of the Paleocene Fort Union Formation. The Knobloch coal core (63 ft long) was divided into 1-ft increments and analyzed using chemical and petrographic methods. Definite variations in maceral content were seen. Preliminary studies show relationship between ash, gelinite, inertinite, and humodetrinite contents. A zone of low gelinite, low humodetrinite, and high inertinite, located in the lower quarter of the seam, implies a period of severe oxidation occurred, possibly as swamp fires. Four zones of high inertinite and high humodetrinite (three in the upper half and one in the lower half of the seam) indicate fluctuations in the water table, allowing moderate oxidation and weathering of plant material and subsequent mechanical reworking of humic grains. Near the center of the seam, a zone of high inertinite, high humodetrinite, and high ash content suggests water levels were high enough to allow significant sediment influx as well as reworking of the humic materials. These conclusions suggest the Knobloch coal is autochthonous and hypautochthonous in origin, a result of several water-table fluctuations and/ormore » climatic changes due to drought.« less

Crow Indian justice: Strategies of informal social control

This study presents ethnographic findings based on fieldwork conducted on the Crow Indian Reservation in Southeast Montana. Special focus is placed on patterns of informal social control which help preserve a condition of communal harmony among reservation Indians. Aspects of kinship obligation, religion, ceremony, and personality are introduced as strategies influencing early socialization and adherence to rules. Off‐reservation problems of assimilation regarding alcohol abuse and adjustment to non‐Indian judicial systems are discussed.

The Structure and Phase of Cloud Tops as Observed by Polarization Lidar

High-resolution observations of the structure of cloud tops have been obtained with polarization lidar operated from a high altitude aircraft. Case studies of measurements acquired from cumuliform cloud systems are presented, two from September 1979 observations in the area of Florida and adjacent waters and a third during the May 1981 CCOPE experiment in southeast Montana. Accurate cloud top height structure and relative density of hydrometers are obtained from the lidar return signal intensity. Correlation between the signal return intensity and active updrafts was noted. Thin cirrus overlying developing turrets was observed in some cases. Typical values of the observed backscatter cross section were 0.1-5 (km/sr) for cumulonimbus tops. The depolarization ratio of the lidar signals was a function of the thermodynamic phase of cloud top areas. An increase of the cloud top depolarization with decreasing temperature was found for temperatures above and below -40 C.