Larry Stetler | South Dakota School of Mines and Technology (original) (raw)

Papers by Larry Stetler

A perennial spring forming a tributary to Battle Creek in the Black Hills was studied to determin... more A perennial spring forming a tributary to Battle Creek in the Black Hills was studied to determine controls on both shallow and deep water sources. Characteristics defining the interface between these sources are poorly understood but are integral to development of a tenable water supply. Seismic reflection has indicated a large fault extending to the basement, potentially cutting the Mississippian Madison Group aquifer. Alluvial deposits consist of interbedded gravel and silt and overlie the Triassic Spearfish formation. Gypsum beds in the upper Spearfish formation dissolve forming conduits for surface runoff to infiltrate into coarse-grained alluvial beds that are in hydraulic connection with the stream channel. Thus, a mixed spring source seems likely. Six piezometers were installed up- and downstream of the spring and monthly water table measurements have been made. Observed water levels have remained steady at each location and are unaffected by precipitation. Shallowing of the...

The former Homestake mine in Lead, SD, has been chosen by the NSF as the location for the propose... more The former Homestake mine in Lead, SD, has been chosen by the NSF as the location for the proposed Deep Underground Science and Engineering Laboratory (DUSEL). Prior to the establishment of the federally-funded facility, an interim early science program is being facilitated by the South Dakota Science and Technology Authority, which currently operates the Sanford Laboratory. Many unique opportunities are associated with early access to the Lab site as well as a number of challenges, including access to services such as power and communications and reconciling desired experiment locations with the approved safely -accessible laboratory areas. Experience gained from observing and participating in research has led to an understanding of best practices for safely and effectively utilizing the Sanford Laboratory area and resources.

Geomorphology, 2018

Abstract Petrographic and geostatistical analysis of linear dune forms on the Hanford Site, south... more Abstract Petrographic and geostatistical analysis of linear dune forms on the Hanford Site, south-central Washington, have resulted in data supporting reinterpretation of depositional environments from eolian to primary glaciofluvial with post-depositional eolian modification. Miocene basalt flows of the Columbia River Basalt Group form the bedrock across the region overlain by Pliocene fluvial deposits from the preglacial Columbia River. Between ~21,000 and 12,000 YBP, glacial outburst floods scoured eastern Washington forming the Channeled Scablands. In the Pasco Basin, floodwaters were ponded behind flow restrictions resulting in deposition of coarse-grained gravel and sand sheets capped by fine-grained cyclic Touchet beds in higher elevation peripheral canyons. Outflow of ponded water mobilized the upper few meters of sediment forming a series of giant current ripples or megaripples. Modification of the surfaces of the megaripples under the influence of the Holocene wind regime has produced an eolian surficial signature. Subsurface excavations in these dune forms revealed the primary glaciofluvial provenance. Sedimentologic and petrographic evidence supports a general winnowing of fine-grained sediments from west to east under the current wind regime and includes both quartz and heavy minerals. These processes have resulted in the formation of an active dune field along the western bank of the Columbia River that overlies flood deposits locally.

Journal of Hydrology, 2018

Geomorphology, 2019

Abstract Identification and characterization of a relict landscape in the Black Hills of South Da... more Abstract Identification and characterization of a relict landscape in the Black Hills of South Dakota has provided insight into the postuplift history (~30 Ma to present). A new watershed decomposition technique has been developed that utilizes high-resolution digital elevation models and traditional long valley profiles to identify the location and extent of the relict landscape as well as its geomorphic characteristics. Results identified an expansive relict landscape at elevation in the center of the Black Hills that contains fluvially mature features such as low-gradient channels and broad flood valleys. Moreover, the relict landscape and associated watersheds that drain it are undergoing active fluvial incision via knickzone migration. This observation suggested that the Black Hills were once much more subdued than today. At present, channel confinement, lack of potential floodwater storage, and steepened stream gradients exists in reaches of active incision downstream of the relict landscape. Large paleofloods influenced by these processes have been well documented and have been restricted to the narrow and steep canyons that drain the relict landscape. Therefore, active fluvial incision into the Black Hills influences the ability of more recent (Holocene) large floods to leave substantial evidence of their occurrence inside incised canyon walls and should also be considered when studying watershed factors influencing large flood events on the flanks of the Black Hills.

SPE Russian Petroleum Technology Conference and Exhibition, 2016

This research proposes to answer the question, what are the directional dependencies of the poroe... more This research proposes to answer the question, what are the directional dependencies of the poroelastic properties of shale? To fully answer this question, the following tasks will be completed. First, determine shale properties: strength, elastic and permeability. Second, determine what effective stress(es), or range, exceeds the shale's tensile strength. Lastly, determine a theoretical model for fracture propagation in shale. A large-scale laboratory experiment has been designed to subject shale to pore over-pressurization and induce tensile fractures bringing the sample to failure. It is anticipated that the pressure differential, elevated pore pressure in a low permeability rock sample, and concomitant bleeding off of confining pressure will induce tensile fractures affected by poroelastic properties of the rock. The results from this experiment will be used to calibrate a forward finite element numerical model, which can then simulate the tensile fracturing process and answ...

The former Homestake Gold Mine in Lead, South Dakota in the United States is being transformed in... more The former Homestake Gold Mine in Lead, South Dakota in the United States is being transformed into the Sanford Underground Research Facility (Sanford Lab) to host a variety of astrophysics experiments deep underground. While operating, Homestake was the deepest underground mine in North America with workings reaching over 2,439 meters deep. With the transformation to Sanford Lab, new laboratories and experiments are in operation and future facilities are planned at the 4850 Level, about 1,490 meters below ground surface. The laboratories are located at great depth to shield sensitive experiments from interference by cosmic radiation. Excavations of unparalleled size and span for such depths are under consideration at Sanford Lab to accommodate instrumentation and conduct long-term experiments. Geotechnical stability and ground control within strict tolerances are required to protect sensitive instruments and ensure personnel safety. One factor that bears on the stability of laborat...

A new methodology was developed to estimate a rock discontinuity roughness using LiDAR data colle... more A new methodology was developed to estimate a rock discontinuity roughness using LiDAR data collected from the 4850-ft level of the Sanford Underground Research Facility (SURF) at the former Homestake Gold Mine, Lead, SD. Maptek’s I-Site Studio and Vulcan 3D mine modeling software packages were used for the analysis. The data was obtained using a Z&F IMAGER 5006h LiDAR scanner that had a maximum resolution of 0.01mm. Data preparation was performed in I-site Studio and the points were triangulated to create a surface. The analytical data consisted of ten rectangular point clouds of dimensions of about 1.1 m by 0.56 m. The triangulated surface was imported into Vulcan where data analyses were performed. Results indicated that this method yields a useful way of estimating the roughness of a 3D rock surface by considering orientation (slope) of triangular facets making up the surface. Using the slope angles the surface roughness parameter Z2s was readily determined and correlated with t...

Uranium, Mining and Hydrogeology, 2008

Applied Geochemistry, 2009

Hydrogeology Journal, 2011

Managing Soils and Terrestrial Systems

A portable wind tunnel has been designed and constructed by senior geological engineering student... more A portable wind tunnel has been designed and constructed by senior geological engineering students enrolled in the capstone course ‘Geological Engineering Design II’ at South Dakota School of Mines and Technology, Rapid City, SD. The project involved research, design, analysis and implementation phases under the constraints of a budget. The experience offered students a first-hand view of an actual design process where critical design decisions were required at various stages of the project. The result was a research quality field wind tunnel that will be used to research wind erosion of soil and sediment from numerous landuse categories across western South Dakota. The tunnel has an overall length of 8.5 m with a working section 4.5 m long, 0.5 m high and 0.5 m wide. Power was supplied using a 6.5 kW generator driving a 0.62 m axial fan. An in-line power inverter allowed a variable current to be supplied to the fan thereby controlling wind speed. A diffuser was used at the downstre...

Potential human health impacts from respiration of dust containing lowlevels of radionuclides wer... more Potential human health impacts from respiration of dust containing lowlevels of radionuclides were evaluated near abandoned uranium mines in Harding County. Specific interest centered on potential disposition of contaminated particles, i.e., are dust particles contaminated with acute concentrations of radionuclides, and where are such particle being deposited. Contaminated particles small enough to settle in the bronchi and lungs could lead to adverse health conditions such as irradiated lung tissue, tumor, atrophy of functional tissue, and increased susceptibility to other disease agents. Samples of surface dust were collected using a portable wind tunnel at 34 sites and analyzed for As, Cu, Pb, Mo, Se, Th, U, and V. All wind-derived dust samples contained As, Cu, Pb, Th and V. Uranium occurred in 32 samples and was above established background (0.74 mg/kg) in 15 samples. For evaluation, all concentrations were converted from mg/kg to pCi/g to allow comparison to radionuclide conce...