The Ellisras Basin, with huge coal resources, is fault-bounded along its southern and northern margins and is a graben-type deposit. The study area is situated in the south-western part of the Limpopo Province of the Republic of South Africa and is geologically located in the Ellisras Basin. In this area the basin is influenced by three major fault zones, the Eenzaamheid Fault delineating its southern limit, the Zoetfontein Fault near its northern limit and the Daarby Fault, with a down-throw of approximately 350 m towards the north-east. Sedimentological facies changes also influence the continuity of the coal zones, with deterioration in coal development. The exploration project was a collaboration between two of the large role players in the South African coal mining industry Sasol and Exxaro, for the purpose of identifying whether the coal in the Ellisras Basin could be used for gasification purposes in the Sasol process, and that enough resources exist on the farms on which the two companies have the exploration rights.. The prospecting method used at the Project area, situated 50 kilometer west of the town of Lephalale in the Limpopo Province of South Africa, comprises the drilling of cored exploration boreholes on a random spacing of ± 1 000 m x 1 000 m, together with infill percussion drilling. The use of slimline geophysical methods to log lithologies is a technique which has been used extensively in the mining industry over a number of years. At the Project area the correlation between the measured densities derived from the traditional method of air and water measurement and those derived from Vectar processed derived densities from geophysical logging is better than 95%. As a method of “fingerprinting” the various coal zones and samples it was decided to calculate the distribution of relative densities in the chosen geological intersection. The data was then used to portray geophysically derived relative density cumulative distribution line diagrams (GDCDD) of the various lithotypes on either a sample-by-sample or zone-by-zone basis. Using the classification method proposed, the various coal seams and zones can be correlated to a high degree and discrepancies easily identified. The lateral correlation between lithologies can be accurately described and substantiated, and this would convince a Competent Person that the method proposed is invaluable in classifying coal resources in the coal basins. / Thesis (PhD)--University of Pretoria, 2014. / lk2014 / Geology / PhD / Unrestricted

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23175号 / 工博第4819号 / 新制||工||1753(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 小池 克明, 教授 林 為人, 准教授 柏谷 公希 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

Many surveying engineering applications require the knowledge of the orientation parameters of instruments. One can use inertial measurement units (IMUs) to determine that. IMUs are combinations of several inertial sensors and comprise at least an accelerometer and a gyroscope. Therefore, they can detect accelerations and angular rates in a three-dimensional space. As micro-electro-mechanical systems, the sensors are increasingly getting smaller and lighter, but without being reduced in their accuracy. The smaller size facilitates diverse placing of the sensors, which allows a variety of uses. Moreover, several low-cost IMUs have been devised since the development of single-board computers. The main objectives of this work are to determine tilts using a low-cost IMU, and the accuracy of the sensor. Furthermore, it studies general IMU applications in surveying engineering, and examines whether low-cost versions are applicable. To fulfil the objectives, the study was based on a selected low-cost IMU. Two programs were developed as part of this work. One was to control the sensor and the other, to calculate the tilts and analyse the data. The IMU was mounted in front of the objective of the total station and aligned in different reference orientations. All measurements were performed under controlled thermal conditions. Thereby, it was ensured that no falsifications could appear due to ambient temperature influences. As a first step, the sensor calibration process was completed. It helped determine the signal offset parameter and their time-dependent change. The calibration was done using two present methods, the six-position and the multi-position methods. The calibrated IMU helped determine the tilts. This was done in the case of the accelerometer via trigonometric functions, which allowed an absolute orientation statement. In contrast, the gyroscope provided relative orientation with the multiplication of the detected angular variance and the time that passed. After that, a target-actual comparison with the reference information of the total station helped determine the external accuracy of the tilt from the IMU. Moreover, multiple measurements could give a statement of the internal accuracy. Finally, the Kalman Filter was added to smooth out the sensor data and combine it in real-time. The calibration methods showed similar results, and it was striking that the sensors did not show the expected drifts. The reason could be related to a pre-calibration by the manufacturer. On the one hand, the used IMU showed differences in the total station alignments in the order of 0.798° for the accelerometer and up to 4.3° for the gyroscope with the calibrated data. On the other, the differences in repeated measurements were at 0.024° for the accelerometer and 0.5° for the gyroscope. It was figured out different possible applications of IMUs in surveying engineering. Among other things, these included orientation monitoring of sensor platforms or the determination of the external orientation of unmanned aerial systems. For these applications, the usability depends on the achievable accuracy. In the case of the IMU chosen in this study, the proven accuracy is too inaccurate for these applications. There is a need for further investigation because the use of another sensor type may rectify the insufficient accuracy problem. Moreover, to achieve better accuracies and to make it possible to use the IMU in different ambient temperatures, the temperature influence must be determined.

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Title: Geophysical survey for deep geothermal energy exploitation at the site Nova Paka Author: Magda Karousová Supervisor: Prof. RNDr. Miloš Karous, DrSc. Supervisor's e-mail address: karous@geonika.com The topic of this thesis is a literature search of geological, geophysical, and geothermal information about wider surroundings of the area of Nova Paka and a complete geophysical survey focused on mapping of deeper fault zones and verification of Permo-Carboniferous sediments thickness. The area has been preliminarily assessed as promising for the use of deep geothermal energy. It belongs to the south-western part of Krkonoše Piedmont Basin. The bedrock of the basin is formed by Proterozoic metamorphites. Heating of surrounding rocks by intrusions of local volcanics during the Younger Tertiary is considered important for geothermal applications. The cover of metamorphic bedrock by sediments may indicate accumulation of the heat from the bedrock at relatively shallow depths of several hundred meters. Geophysical measurements, namely reflection and refraction seismics, gravimetry and resistivity profiling identified two major fault zones of east-west and northwest-southeast direction. The interpretation of the data obtained by geophysical sounding methods, namely seismic reflection and vertical...

Inversion and Depth Range of Dipole Electromagnetic Induction Measurements in Geophysics Fernando César Moura de Andrade Institute of Hydrogeology, Engineering Geology and Applied Geophysics Faculty of Science, Charles University Electromagnetic induction geophysical methods are, basically, composed by a transmitter which produces a magnetic field and a set of receivers which measure the primary magnetic field, from the transmitter, superimposed by secondary magnetic fields inducted in the subsurface. Equipment operating at, relatively, low frequencies and with short distances between the transmitter and the receivers are usually called conductivity meters and operate at low inductions numbers. The depth of investigation, in such kind of equipment, depends mainly on the transmitter-receiver distance, on the orientations of the magnetic dipoles and the height of the instrument from the ground, in order that a depth sounding can be done changing these parameters in a single measurement location. Making a series of these multi-configuration measurements, two-dimensional, or even three-dimensional surveys, can be performed and, subsequently, inverted in order to produce an image of the subsurface of the earth. Forward modelling and inversion of multi-configuration electromagnetic induction data can be made...

The variable contexts of Fremont habitation sites in Utah Valley often make identification of those sites very challenging for archaeologists. Pit houses and other structures throughout the valley are frequently in plowed fields or other disturbed contexts that obscure their more exact location and nature. The application of geophysical technologies at archaeological sites throughout the world, including in North America, has proven to be an effective means of subsurface archaeological survey. However, geophysical techniques have been underutilized in Fremont archaeology. This paper reports on the employment of two geophysical methods, ground-penetrating radar (GPR) and fluxgate gradiometer surveys, at three known Fremont habitation sites in southern Utah Valley – the Wolf Village, Wolf Mound, and Snow Farm sites. The preliminary geophysical surveys and later ground-truthing of various geophysical anomalies reveals the effectiveness of these methods in identifying where architectural or other cultural features exist below the surface.

<div> <div> <div> <p>The combination of field-based studies and numerical modeling provides a robust tool for evaluating geologic and geodynamic processes along a convergent margin. Complex and persistent tectonic activity and a novel suite of geophysical observations make the southern Alaskan convergent margin a key region to evaluate these processes through both basin analysis studies and geodynamic modeling. This conceptual approach is utilized to explore the active driving forces of surface deformation throughout southcentral Alaska, as well as the geologic record of regional Cenozoic tectonic processes. </p> <p>New sedimentologic, chronostratigraphic, and provenance data from strata that crop out within the central Alaska Range document a previously unrecognized stage of Eocene – early Miocene strike-slip basin development along the northern side of the central Denali fault system. This stage was followed by Miocene-Pliocene deformation and exhumation of the central Alaska Range, and basin development and northward sediment transport into the Tanana foreland basin. This portion of the study provides insight into Cenozoic tectonics and basin development in the central Alaska Range. </p> <p>How transpressional tectonics are manifest in the modern-day, in combination with shallow subduction processes, are not well understood for the southern Alaskan convergent margin. Simulations of the 3-D deformation of this region allow for investigation of the complex relationship between these tectonic processes and surface deformation. Results from this study display the far-field affect that strong plate coupling along the shallowly subducting Yakutat slab has on the surface deformation of southcentral Alaska. Our models also show that partitioning of this convergence is observed along the Denali fault system. Additionally, our results indicate the subducting slab is segmented into separate Pacific, Yakutat and Wrangell slab segments. This variation in slab structure exerts control on the upper plate response to shallow subduction.</p> </div> </div> </div>

Carter Mansion is a well-known historic site in Tennessee. It is estimated to have been built in the 1770s and is believed to be the oldest frame house, a house with a wooden skeleton for the base, in the state. This house was built by John and Landon Carter, father, and son respectively, who were well known influential leaders of the Watauga Settlement in the late 18th century. Prior to their arrival, the area was home to Native Americans. The aim of this research was to perform a geophysical survey of a previously unresearched area of the site, providing guidance for future development of the property. A ground penetrating radar (GPR) survey was conducted with a GSSI SIR4000 with 400 MHz antennas. Previous research was able to identify both historic and prehistoric graves in other areas of the property. This project extends this knowledge and aims to determine if there are graves associated with the headstones of the Carters on the eastern margin of the property, thus enriching the history and prehistory of the site without disturbing the grounds.

In this thesis, the results from a geophysical mapping and coring campaign of Lagoa das Furnas are presented. Specific focus is placed on the origin of a subaqueous volcanic cone mapped in the southern part of the lake. Lagoa das Furnas is a crater lake within the Furnas volcanic centre which is located on the island of São Miguel in the Azores archipelago. The Furnas volcanic centre has a long history of earthquakes and volcanic activity. The area is relatively well-studied, except for the lake floor. Therefore, a high resolution geophysical and geological mapping survey was conducted at Lagoa das Furnas. Sidescan sonar was used to map the surface of the lake floor and single beam sonar was used to acquire sub-bottom profiles. In addition to the geophysical mapping, sediment surface sampling and core drilling were carried out followed by geochemical analyses of the retrieved material. The mapped data permitted a characterisation of the floor of Lagoa das Furnas and revealed several volcanic features including fumarole activity and a volcanic cone in the southern part of the lake. In order to unravel the origin of this cone several methods were applied, including analyses of tephra and minerals collected from the cone itself and from nearby deposits of two known eruptions Furnas I and Furnas 1630. Sedimentological, petrological, geochemical and geochronological studies of pyroclastic deposits from the cone suggest a subaqueous eruption linked to the Furnas 1630 eruption. The chemistry of glass and crystal fragments sampled from the cone suggests that it is composed of more evolved magma than that of the main Furnas 1630 implying that the lake cone is likely a product of the last eruptional phase. Historical documents reveal three lakes in Furnas valley before the 1630 eruption. Two of these lakes were lost due the eruption and the remaining lake is most likely Lagoa das Furnas and consequently did exist before the 1630 eruption.