Physical Sciences and Mathematics Commons^™

Concentrations And Isotope Ratios Of Dissolved Inorganic Carbon In Denitrifying Environments, C. Nascimento, Eliot A. Atekwana, R. V. Krishnamurthy

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

We measured the concentration and isotope ratio of dissolved inorganic carbon (DIC) in groundwater associated with denitrification (C_org + NO₃^- = CO₂ + N₂) in an agriculturally impacted site in southwestern Michigan. Samples with the lowest nitrate levels also had low dissolved oxygen content and were more depleted in δ¹³C than background groundwater. All the samples had DIC concentrations in excess of titratable alkalinity. The magnitude of this DIC in excess of alkalinity correlated with a decreasing δ¹³C attesting to the presence of CO₂ derived from organic carbon. Carbon …

Cycle Symmetry And Its Causes, Cisco Group (Virgilian And Wolfcampian), Texas, Wan Yang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

181 transgressive-regressive cycles composed of nonmarine and marine carbonate and siliciclastic rocks of the Cisco Group on the Eastern Shelf, Texas, display complex characteristics at both hemicycle and full-cycle scales. They are delineated on the basis of successive changes of depositional environments, stratal boundary relations, and stratigraphic position. Transgressive and regressive stratigraphic environment gradients are defined as the magnitude of environmental shift divided by thickness for each hemicycle. They indicate the rates of lateral environmental shifts during transgression and regression. Cycle symmetry index is defined as the ratio between transgressive and regressive stratigraphic environment gradients. It provides a measure of …

Localized Amplification Of Seismic Waves And Correlation With Damage Due To The Northridge Earthquake: Evidence For Focusing In Santa Monica, Stephen S. Gao, Kelly H. Liu, Paul M. Davis, Leon Knopoff

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The analysis of seismograms from 32 aftershocks recorded by 98 seismic stations installed after the Northridge earthquake in the San Fernando Valley, the Santa Monica Mountains, and Santa Monica, California, indicates that the enhanced damage in Santa Monica is explained in the main by focusing due to a lens structure at a depth of several kilometers beneath the surface and having a finite lateral extent. The diagnosis was made from the observation of late-arriving S phases with large amplitudes, localized in the zones of large damage. The azimuths and angles of incidence of the seismic rays that give rise to …

Data Report For The 1993 Los Angeles Region Seismic Experiment (Larse93), Southern California: A Passive Study From Seal Beach Northeastward Through The Mojave Desert, Monica D. Kohler, Paul M. Davis, Kelly H. Liu, Mark Benthien, Stephen S. Gao, Gary S. Fuis, Robert W. Clayton, David Okaya, James Mori

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

This report contains a description of the first part of the Los Angeles Region Seismic Experiment (LARSE). To date, LARSE has consisted of two experiments: passive, which took place in fall, 1993 (LARSE93), and active, which took place in fall, 1994 (LARSE94). The goal of the 1993 experiment was to collect waveform data from local and distant earthquakes to obtain three-dimensional images of lower crust and upper mantle structure in Southern California, particularly under the San Gabriel Mountains and across the San Andreas fault. During LARSE93, approximately 88 stations were deployed in a 175-km-long, linear array across the Los Angeles …

Vertical Resolution Of A Seismic Survey In Stratigraphic Sequences Less Than 100 M Deep In Southeastern Kansas, Richard Daniel J. Miller, Neil Lennart Anderson, Howard Randall Feldman, Evan K. Franseen

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

A 400-m long, 12-fold high-resolution common depth point (CDP) reflection seismic profile was acquired across shallow converging Pennsylvanian strata in the Independence area of southeastern Kansas. One of the principal objectives was to determine practical vertical resolution limits in an excellent shallow seismic-data area with borehole control. The dominant frequency of the CDP stacked data is in excess of 150 Hz based on peak-to-peak measurements. Interference phenomena observed on stacked seismic data incorporated with models derived from log and drill-hole information suggest a practical vertical resolution limit of about 7 m, or one-third of the dominant wavelength. The data suggest …

Sks Splitting Beneath Southern California, Kelly H. Liu, Paul M. Davis, Stephen S. Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Measurements of SKS phase splitting were obtained from nineteen seismic stations in southern California. The fast polarization directions are 53° at the southern end of the Great Valley, 82 ± 8° in the western Transverse Ranges and northern Peninsular Ranges, 95 ± 4° in Mojave Desert, and 70° on San Clemente Island. The splitting time ranges from 0.8 to 1.8 seconds, which is consistent with an anisotropic layer of 100 to 200 km thick for 4% anisotropy.

Asymmetric Upwarp Of The Asthenosphere Beneath The Baikal Rift Zone, Siberia, Stephen S. Gao, Paul M. Davis, Kelly H. Liu, Philip D. Slack, Yu A. Zorin, Nikolai A. Logatchev, M. Kogan, P. D. Burkholder, Robert P. Meyer

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In the summer of 1991 we installed 27 seismic stations about lake Baikal, Siberia, aimed at obtaining accurately timed digital seismic data to investigate the deep structure and geodynamics of the Baikal rift zone and adjacent regions. Sixty-six teleseismic events with high signal-to-noise ratio were recorded. Travel time and Q analysis of teleseisms characterize an upwarp of the lithosphere-asthenosphere boundary under Baikal. Theoretical arrival times were calculated by using the International Association of Seismology and Physics of the Earth's interior 1991 Earth model, and travel time residuals were found by subtracting computed arrival times from observed ones. A three-dimensional downward …

Sporomorphs And Palynological Interpretations Of Lower Oligocene Strata From The Eastern Gulf Coast, U.S.A., Lisa M. Reeves

Opportunities for Undergraduate Research Experience Program (OURE)

The Vicksburg Group in the eastern Gulf Coast of the United States belongs to one of the most complete and continuous Paleogene strata in the world. Previous studies in this region have neglected the rich palynomorph assemblages of the Lower Oligocene units of the Vicksburg Group. Four samples from Wayne County Mississippi were analyzed for palynological information on the Vicksburg Group. The initial objective of the study was to understand the principles of palynology and the basis for sporomorph identification. A minimum of 300 specimens were counted per slide to determine the distribution of sporomorphs in the sediments. Two hundred …

An Integrated Surface And Borehole Seismic Case Study: Fort St. John Graben Area, Alberta, Canada, Ronald C. Hinds, Richard Kuzmiski, Neil Lennart Anderson, Barry R. Richards

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The deltaic sandstones of the basal Kiskatinaw Formation (Stoddard Group, upper Mississippian) were preferentially deposited within structural lows in a regime characterized by faulting and structural subsidence. In the Fort St. John Graben area, northwest Alberta, Canada, these sandstone facies can form reservoirs where they are laterally sealed against the flanks of upthrown fault blocks. Exploration for basal Kiskatinaw reservoirs generally entails the acquisition and interpretation of surface seismic data prior to drilling. These data are used to map the grabens in which these sandstones were deposited, and the horst blocks which act as lateral seals. Subsequent to drilling, vertical …

An Integrated Surface Seismic/Seismic Profile Case Study: Simonette Area, Alberta, Ronald C. Hinds, Neil Lennart Anderson, Richard Kuzmiski

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

On the basis of conventional surface seismic data, the 13-15-63-25W5M exploratory well was drilled into a low-relief Leduc Formation reef (Devonian Wood-bend Group) in the Simonette area, west-central Alberta, Canada. The well was expected to intersect the crest of the reef and encounter about 50-60 m of pay; unfortunately it was drilled into a flank position and abandoned. The decision to abandon the well, as opposed to whipstocking in the direction of the reef crest, was made after the acquisition and interpretive processing of both near-and far-offset (252 and 524 m, respectively) vertical seismic profile (VSP) data, and after the …

An Overview Of Some Of The Large Scale Mechanisms Of Salt Dissolution In Western Canada, Neil Lennart Anderson, Ralph W. Knapp

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Well log and seismic data indicate that the bedded rock salts of the Devonian Prairie Formation were widely distributed and uniformly deposited in the Lloydminster area, Western Canada; however, as a result of extensive leaching, the distribution of these salts is not now what it once was. The Lloydminster area is now bisected by the north-south trending main dissolutional edge of the Prairie salt. Thick salt (up to 150 m) is preserved to the west of this edge; to the east the salt is mostly absent. The paper presents an overview of the envisioned principal mechanisms of salt dissolution. The …

Westhazel General Petroleums Pool: Case History Of A Salt- Dissolution Trap In West-Central Saskatchewan, Canada, Neil Lennart Anderson, Dale A. Cederwall

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The Westhazel General Petroleums (GP) Pool of west-central Saskatchewan, Canada, produces from the GP member of the Lower Cretaceous Mannville Group. This reservoir is structurally closed across the updip, eastern dissolutional edge of the underlying Middle Devonian rock salt of the Leofnard Member, Prairie Formation. The leaching of these salts occurred in post-Mannville time in the Westhazel area and caused the regional southwest dip of the General Petroleums member to be locally reversed.The Westhazel GP Pool, from a geophysical perspective, is characteristic of many of the shallow Lower Cretaceous pools situated along the dissolutional edge of the Prairie salt. The …

Dolomite Cement Stratigraphy Of The Reelfoot Rift And The Relationship Of These Cements To Dolomite Cements Found In Southeast Missouri, Timothy James Keller

Opportunities for Undergraduate Research Experience Program (OURE)

The formation of the southeast Missouri Mississippi Valley-type Pb, Zn, Cu ore districts have been a subject of controversy. Using petrology and geochemistry, earlier studies have attempted to reveal fluid flow, composition, and origin of the ore forming fluids. In this study, the potential role of the Reelfoot rift (New Madrid seismic zone) as a source and/or conduit for ore forming fluids is addressed. By observing cuttings and cores from four oil test wells within the Reelfoot rift using cathodluminescence, four cement types were described: 1) A multiple generation cement type similar to that observed associated with mineralization in southeastern …

Depositional Facies Analysis And Sea Level Curve Determination From The Soth Western St. Francois Mts. To The Western Margin Of The Reelfoot Rift, Missouri, Aaron Ramon Rezendez

Opportunities for Undergraduate Research Experience Program (OURE)

Knowledge of the relative influence of eustatic and tectonic controls on sedimentation in basins is important to developing a regional facies model. The Reelfoot Rift basin is located on the southern margin of the North American Craton. The tectonic and sedimentary history of the rift began during Middle Cambrian time and extended through the Early Ordovician. Oil test well cuttings and cores were used to construct a stratigraphic fence extending from the Cambro- Ordovician platform west of the St. Francois Mts. southeastward info the rifted basin. Three major transgressive-regressive sequences and numerous minor transgressive-regressive sequences were observed in Cambro-Ordovician rocks …

Influence Of The Mcdowell Sanitary Landfill On Groundwater Quality, Phelps County, Missouri, Christine E. Bough

Opportunities for Undergraduate Research Experience Program (OURE)

This is a case study of the groundwater quality near the McDowell Sanitary Landfill in Phelps County, Missouri. The landfill is located in section 21 of T37N R8W off of Missouri State Highway CC. This landfill is a near surface solid waste disposal facility above the groundwater table located in an abandoned area of a rock quarry. The thickness, lithology, and structure of the material beneath the landfill, and the design of the landfill itself, will influence the time of contaminant transport and degree of modification in the event that leachate escapes the landfill. Among the more important topographic features …

A Seismic Analysis Of Black Creek And Wabumun Salt Collapse Features, Western Canadian Sedimentary Basin, Neil Lennart Anderson, Robert James Sidford Brown

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

These salt remnants and their associated collapse features are often associated with structural or stratigraphic traps. As a result of the relationships between dissolution and hydrocarbon entrapment, the distribution (areal extent and thickness) of these salt remnants is of significant interest to the explorationist. Seismic information about the thickness and the extent of these salts should be used together with well log control to generate subsurface distribution maps. These maps will facilitate both the delineation of prospective structural and stratigraphic play fairways and the determination of the timing of salt dissolution. In addition, an appreciation of regional salt distribution will …

Differential Compaction Of Winnipegosis Reefs: A Seismic Perspective, Neil Lennart Anderson, Evan K. Franseen

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Winnipegosis Formation reefs in southern Saskatchewan are typically encased in the thick, apparently incompressible salts of the Prairie Evaporite. Illustrates the usefulness of seismic data to separate postdepositional compaction features from primary features to determine the primary morphology of a reef better and to determine the relative amounts of postdepositional compaction with the different reef environments.

Low- And High-Relief Leduc Formation Reefs: A Seismic Analysis, Neil Lennart Anderson, Robert James Sidford Brown, Ronald C. Hinds

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Leduc reefs have grown to widely varying heights and aereal extents along the Rimbey-Meadowbrook trend of central Alberta, resulting in significantly different seismic signatures. Three examples considered in this paper include two high-relief or full reefs from the Leduc-Woodbend field, an atoll and a pinnacle, each around 200 m in height but differing greatly in areal extent, about 100 km² for the atoll and 1 km² for the pinnacle. The third example, a low-relief or basalt reef from the Morinville field, is about 100 m high and 1 km² in areal extent.

The Leduc-Woodbend and Morinville reefs …

Seismic Signature Of A Swan Hills (Frasnian) Reef Reservoir, Snipe Lake, Alberta, Neil Lennart Anderson, Robert James Sidford Brown, Ronald C. Hinds, L. V. Hills

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Swan Hills formation (Frasnian stage) carbonate buildups of the Beaverhill Lake group are generally of low relief and considerable areal extent and are overlain by and encased within the relatively high-velocity shale of the Waterways formation, which thins but does not drape across the reefs. Consistent with this picture, prereef seismic events are not significantly pulled up beneath the reefs nor are postreef events draped across them. Indeed, the seismic images of these reefs are effectively masked by the high-amplitude reflections from the overlying top of the Beaverhill Lake group and underlying Gilwood member and cannot be distinguished from those …

An Economical Field Datalogger, Norbert H. Maerz, M. B. Dusseault, R. W. Gillham

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Data acquisition is important in geotechnical and hydrological field investigations. Commercially available data acquisitions systems are often not well suited to field use, and can be costly. An alternative to buying a data acquisition system is to build one, and recent advances in computer micro-chip technology have made it easy to understand, design and build simple data acquisition devices.

The design of a data acquisition system developed at the University of Waterloo, along with an example of its use, is discussed in the paper. The intent was to sample 16 channels at 12 bit resolution for prolonged periods under adverse …

Microcomputer Image Analysis Of Rock Fabric, Norbert H. Maerz, C. P. Bennettt, B. A. Dony

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The behavior of many types of rock is largely dependent on the fabric of the rock mass. Current methods of manually measuring the discontinuity networks in rock masses are slow, tedious and error prone. The alternative is to make automated measurements of rock jointing parameters on digital images of rock faces in mines, tunnels, and surface excavations.

Photoanalysis techniques are being developed to measure various rock fabric parameters. Techniques presented here include the generation of a joint trace map from a photograph, and the measurement of simple statistics on the joint trace map. Methods are also presented for the determination …

Investigation Of Present Thermal Regime Of Missouri River In Missouri, James C. Maxwell

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The applicability of power spectral density techniques, Fourier series analysis, and linear regression to the mathematical modeling of river water temperature is demonstrated. Consideration is also given to the problem of estimating thermal inputs to rivers from man-made sources such as electrical power plants. First, power spectral density techniques are used in the time-series analysis of water temperature records which were taken from the Missouri River. Two spectral ranges are then studied from the standpoint of their applicability to (1) mathematical model building and (2) detection and identification of cyclic thermal inputs. Next, a Fourier regression fit to the time-series …

Gravity Investigations Over A Salt Structure Near Lübbecke, Northern Germany, Reinhard K. Frohlich

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

A detailed gravity survey was conducted parallel to the “Wiehengebirge” northwest of Minden in Northern Germany. The survey localized between Liibbecke and Levern a salt deposit, which is known as “Münder Mergel” salt of the Upper Jurassic. The salt deposit forms a cylindrical structure with an axis striking NWW. With a deep drill hole detailed interpretation was possible using the polygon method of TALWANI, WORZEL and LANDISMAN [1959], The section shapes of salt bodies under eight profiles show asymmetrical figures of two salt units. Both increase in thickness strongly to the northeast, where the salt is interrupted by a fault …