Divergence along a steep ecological gradient in lake whitefish (Coregonus sp.)

To understand mechanisms structuring diversity in young adaptive radiations, quantitative and unbiased information about genetic and phenotypic diversity is much needed. Here, we present the first in-depth investigation of whitefish diversity in a Swiss lake, with continuous spawning habitat sampling in both time and space. Our results show a clear cline like pattern in genetics and morphology of populations sampled along an ecological depth gradient in Lake Neuchâtel. Divergent natural selection appears to be involved in shaping this cline given that trait specific P(ST)-values are significantly higher than F(ST)-values when comparing populations caught at different depths. These differences also tend to increase with increasing differences in depth, indicating adaptive divergence along a depth gradient, which persists despite considerable gene flow between adjacent demes. It however remains unclear, whether the observed pattern is a result of currently stable selection-gene flow balance, incipient speciation, or reverse speciation due to anthropogenic habitat alteration causing two formerly divergent species to collapse into a single gene pool.

INTEGRATED ASSESSMENT OF ANTHROPOGENIC, CLIMATE, AND POLICY INDUCED CHANGES OF PHOSPHORUS EXPORT IN THE UNITED STATES LAURENTIAN GREAT LAKES WATERSHEDS

Anthropogenic activities have increased phosphorus (P) loading in tributaries to the Laurentian Great Lakes resulting in eutrophication in small bays to most notably, Lake Erie. Changes to surface water quality from P loading have resulted in billions of dollars in damage and threaten the health of the world’s largest freshwater resource. To understand the factors affecting P delivery with projected increasing urban lands and biofuels expansion, two spatially explicit models were coupled. The coupled models predict that the majority of the basin will experience a significant increase in urban area P sources while the agriculture intensity and forest sources of P will decrease. Changes in P loading across the basin will be highly variable spatially. Additionally, the impacts of climate change on high precipitation events across the Great Lakes were examined. Using historical regression relationships on phosphorus concentrations, key Great Lakes tributaries were found to have future changes including decreasing total loads and increases to high-flow loading events. The urbanized Cuyahoga watersheds exhibits the most vulnerability to these climate-induced changes with increases in total loading and storm loading , while the forested Au Sable watershed exhibits greater resilience. Finally, the monitoring network currently in place for sampling the amount of phosphorus entering the U.S. Great Lakes was examined with a focus on the challenges to monitoring. Based on these interviews, the research identified three issues that policy makers interested in maintaining an effective phosphorus monitoring network in the Great Lakes should consider: first, that the policy objectives driving different monitoring programs vary, which results in different patterns of sampling design and frequency; second, that these differences complicate efforts to encourage collaboration; and third, that methods of funding sampling programs vary from agency to agency, further complicating efforts to generate sufficient long-term data to improve our understanding of phosphorus into the Great Lakes. The dissertation combines these three areas of research to present the potential future impacts of P loading in the Great Lakes as anthropogenic activities, climate and monitoring changes. These manuscripts report new experimental data for future sources, loading and climate impacts on phosphorus.

Archeological Investigations at the Big Creek Lake Site (24RA34)

In August 1977 excavation was conducted at the Big Creek Lake site -24RA34- at the outlet of the 91g Creek Lakes, Selway-Bitterroot Wilderness Area, Ravalli County, Montana. The site contained shallow, disturbed deposits and lacks any statisgraphic separation. One of these occupations was identified by a projectile point type not previously reported from the area. This was termed Big Creek Corner Notched and its temporal affiliation is not precisely known. Comparative material from Colorado and Alberta suggest either Early Archaic or Late Archaic affiliation. The occupations exemplified by Big Creek Corner Notched points and by Pelican Lake-Elko points (Late Archaic 1000 B.B – A.D. 200) were the most prevalent at the site. Less intensive occupations are by ·Middle Plains Archaic McKean points and Late Prehistoric small side notche arrow points. Microscopic analysis of tool working edges shows several of the projectile point forms were used as multi-functional implements. especially as butchering tools. Many of the types of chipped stone recovered from the site are from known sources in western Montana; indicating group movements within the eastern portion of the Intermountain region. Based on the numerous projectile points and cutting tools, the site is interpreted as a seasonally occupied base camp for hunters.

The Testing and Concentration of Lake Chelan Copper Ore

The geologic history of the Holden area and Lake Chelan district is an integral part of the history of the Cascade Mountain Range. The structure is very complex and the rocks, which have been subjected to intense metamorphic action, are portions of a roof pendant and consists of gneisses, schists and quartzites that are often difficult to correlate.

Ground Water in the Lake Basin Field and Adjacent Area

This thesis consists of studying the stratigraphic and structural features of the Lake Basin Field and an adjacent area with special emphasis upon the ground water conditions present.

Study of particle movement in the nearshore region of Lake Superior with radioisotope tracers

Biogeochemical processes in the coastal region, including the coastal area of the Great Lakes, are of great importance due to the complex physical, chemical and biological characteristics that differ from those on either the adjoining land or open water systems. Particle-reactive radioisotopes, both naturally occurring (210Pb, 210Po and 7Be) and man-made (137Cs), have proven to be useful tracers for these processes in many systems. However, a systematic isotope study on the northwest coast of the Keweenaw Peninsula in Lake Superior has not yet been performed. In this dissertation research, field sampling, laboratory measurements and numerical modeling were conducted to understand the biogeochemistry of the radioisotope tracers and some particulate-related coastal processes. In the first part of the dissertation, radioisotope activities of 210Po and 210Pb in a variability of samples (dissolved, suspended particle, sediment trap materials, surficial sediment) were measured. A completed picture of the distribution and disequilibrium of this pair of isotopes was drawn. The application of a simple box model utilizing these field observations reveals short isotope residence times in the water column and a significant contribution of sediment resuspension (for both particles and isotopes). The results imply a highly dynamic coastal region. In the second part of this dissertation, this conclusion is examined further. Based on intensive sediment coring, the spatial distribution of isotope inventories (mainly 210Pb, 137Cs and 7Be) in the nearshore region was determined. Isotope-based focusing factors categorized most of the sampling sites as non- or temporary depositional zones. A twodimensional steady-state box-in-series model was developed and applied to individual transects with the 210Pb inventories as model input. The modeling framework included both water column and upper sediments down to the depth of unsupported 210Pb penetration. The model was used to predict isotope residence times and cross-margin fluxes of sediments and isotopes at different locations along each transect. The time scale for sediment focusing from the nearshore to offshore regions of the transect was on the order of 10 years. The possibility of sediment longshore movement was indicated by high inventory ratios of 137Cs: 210Pb. Local deposition of fine particles, including fresh organic carbon, may explain the observed distribution of benthic organisms such as Diporeia. In the last part of this dissertation, isotope tracers, 210Pb and 210Po, were coupled into a hydrodynamic model for Lake Superior. The model was modified from an existing 2-D finite difference physical-biological model which has previously been successfully applied on Lake Superior. Using the field results from part one of this dissertation as initial conditions, the model was used to predict the isotope distribution in the water column; reasonable results were achieved. The modeling experiments demonstrated the potential for using a hydrodynamic model to study radioisotope biogeochemistry in the lake, although further refinements are necessary.

Subsurface to Surface Correlation of the Tensleep Sandstone in the West Flank of the Pryor Mountains in Carbon County, Montana

The Pennsylvanian Tensleep Sandstone is an eolian and nearshore marine/sabka quartz arenite unit with prominent outcrops along the western Pryor/Bighorn Mountain front east of Red Lodge, MT. Regionally, the formation represents one of the largest ergs in the global geologic record. High permeability makes it an important oil and gas reservoir and aquifer in south central Montana and throughout much of Wyoming. The Tensleep Sandstone’s high percentage of quartz content and grain roundness, due to its eolian origin, makes it a prospective source for natural proppant sand. Three continuous 4-inch cores were obtained during a cooperative project between Montana Tech and industry partners. Using stratigraphic sections, cores, thin sections, and x-ray fluorescence (XRF) analysis, the usefulness and economic feasibility of the Tensleep Sandstone as a minable hydraulic fracture proppant was explored. Usefulness depends on cementation, grain shape, grain size, and depth from surface of the prospective zone. Grain shape and size were determined by thin sections, sieving, and stereomicroscope analysis. Analysis of 20 disaggregated sand samples has shown that as much as 30 percent of the grain sizes fall between 30-50 mesh (medium- to finegrained sand size) and about 45 percent of the grain sizes fall between 70–140 mesh (very fine-grained sand to coarse silt), grain sizes appropriate for some hydraulic fracture operations. Core descriptions and XRF data display the distribution of lithology and cementation. Core descriptions and XRF data display the distribution of lithology and cementation. Elemental (XRF) analyses help to delineate more pure quartz sands from those with grain fractions reflecting fine-grained clastic and evaporitic inputs. The core and nearby stratigraphic sections are used to quantify the amount of overburden and the 3 amount of resource in the area. Initial results show favorable crush strength and useable grain size and shape.

Kibbey Sandstone in Montana

Much attention has recently been given, by geolog­ists, to prolific water bearing horizon and a potent­ial oil horizon, known as the Kibbey sandstone, which lies deeply buried under much of central Montana. In some local­ities the sandstone is dry, and its identification in cut­tings from deep wells has in many cases proved difficult.

The Problem of the Tensleep Sandstone

Sandstone is probably one of the most important groups of rocks in existence today. The economic importance of so insignifi­cant a thing as a mass of sand grains grows with the true reality of the situation. By increasing our knowledge of grains of sand, or particles of sandstone in all their ram­ifications, it would undoubtedly reflect upon our everyday life by increasing commercial possibilities of an undevel­oped natural resource of Montana.