Дисертації з теми "Aeromagnetics"
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Bontenakel, Alexander P. "Three dimensional modelling of the Truro-Sandleton area using aeromagnetics and gravity /." Title page, contents and abstract only, 1992. http://web4.library.adelaide.edu.au/theses/09S.B/09s.bb722.pdf.
Повний текст джерелаOn title page: "National Grid reference: Adelaide sheet S1 54-9 (1:250 000). Map in pocket inside back cover. Includes bibliographical references (leaves 23-25).
Sahu, Bijay Kumar. "Aeromagnetics of selected continental areas flanking the Indian Ocean : with implications for geological correlation and reassembly of Central Gondwana." Doctoral thesis, University of Cape Town, 2000. http://hdl.handle.net/11427/10718.
Повний текст джерелаThomson, G. F. "Palaeomagnetic and aeromagnetic studies of some sulphide deposits." Thesis, University of Newcastle Upon Tyne, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383983.
Повний текст джерелаWhiting, Thomas H. "A study of the lithology and structure of the eastern Arunta Inlier based on aeromagnetic interpretation : a lithological subdivision and structural history of the eastern Arunta Inlier, with particular emphasis on the relationship between magnetic mineral petrogenesis, rock magnetism and aeromagnetic signature /." Title page, contents and abstract only, 1987. http://web4.library.adelaide.edu.au/theses/09PH/09phw6125.pdf.
Повний текст джерелаCasto, Daniel W. "Calculating depths to shallow magnetic sources using aeromagnetic data from the Tucson Basin." Tucson, Ariz. : U.S. Dept. of the Interior, U.S. Geological Survey, 2001. http://geopubs.wr.usgs.gov/open-file/of01-505/.
Повний текст джерелаNaudé, Corus. "Target selection from airborne magnetic and radiometric data in Steinhausen area, Namibia." Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1001520.
Повний текст джерелаJohnson, Ashley Charles. "A geophysical investigation of crustal structure and segmentation of the central Antarctic Peninsula." Thesis, Open University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266417.
Повний текст джерелаGarrett, S. W. "Interpretation of regional gravity and aeromagnetic surveys of the Antarctic Peninsula." Thesis, University of Cambridge, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373905.
Повний текст джерелаLucius, Jeffrey E. "Crustal geology of Ohio inferred from aeromagnetic and gravity anomaly analysis." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1318868502.
Повний текст джерелаMagaia, Luis. "Processing Techniques of Aeromagnetic Data. Case Studies from the Precambrian of Mozambique." Thesis, Uppsala universitet, Geofysik, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-183714.
Повний текст джерелаLeblanc, G. "Wavelet analysis denoising of aeromagnetic data, application to hydrocarbon and mineral exploration." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0035/NQ66216.pdf.
Повний текст джерелаUkaigwe, Nnaemeka Francis. "Interpretation of aeromagnetic data of the Olary province, South Australia and the development of interpretation methods /." Title page, contents and summary only, 1985. http://web4.library.adelaide.edu.au/theses/09PH/09phu34.pdf.
Повний текст джерелаKeating, Pierre B. "The inversion of time-domain airborne electromagnetic data using the plate model /." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75772.
Повний текст джерелаPresent interpretation techniques are based on the use of nomograms (i.e. families of pre-computed characteristic responses) and the method is easily amenable to digital processing as it is easy to program and economic to use. For high accuracy interpretation however it is necessary to develop quantitative interpretation techniques that can make full use of all the data available. Inverse theory has been used with great success in all branches of geophysics, but to date in mining exploration it has been used for the interpretation of airborne E.M. data using only the one layer earth model. Use of inverse theory for the plate model has been limited by the high cost of numerically solving the forward problem.
In this thesis we show how to use inverse theory to interpret time domain E.M. data with the rectangular thin plate model by introducing some economies. It is then possible to estimate parameter errors, the correlation matrix and to assess the validity of the model. This is extended to the joint inversion of magnetic and aeromagnetic data a case that often arises in mining problems. It is finally shown that under some assumptions the late time channels can be used to interpret time domain E.M. data in the presence of conductive overburden. ftn$ sp1$Registered trademark of Barringer Research Ltd.
Kennedy, Roger J. "A 3-D gravity and aeromagnetic interpretation of the Black Hill - Cambrai region /." Title page, contents and abstract only, 1989. http://web4.library.adelaide.edu.au/theses/09SB/09sbk36.pdf.
Повний текст джерелаChan, Mei-ki. "Gravity and aeromagnetic modelling of the Longmenshan Fold-and-Thrust Belt, SW China." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/b4020330x.
Повний текст джерелаChan, Mei-ki, and 陳美琪. "Gravity and aeromagnetic modelling of the Longmenshan Fold-and-Thrust Belt, SW China." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B4020330X.
Повний текст джерелаMartin, J. E. "Spectral analysis of aeromagnetic data and investigation of errors in spherical harmonic models." Thesis, University of Newcastle Upon Tyne, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376255.
Повний текст джерелаStröm, Tobias. "A geophysical study of the Mertainen area : Modelling and interpretation of primarily aeromagnetic data." Thesis, Luleå tekniska universitet, Geovetenskap och miljöteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-63850.
Повний текст джерелаNautanen Deformation Zone, är en framträdande deformationszon i Malmfälten området, vilken är av betydelse att förstå för mineral prospekterings ändåmål. Trotts att det finns ett stort utbud av geofysiska data i Malmfälten och att det finns en god korrelation mellan de flyggeofysiska mätningarna och geologiska observationer, så har området inte undersökts fullständigt med den tillgängliga datan. En geologisk struktur i koppling till apatit järn malms fyndigheten Mertainen has studerats. Bland metoder ingår studie av geologiska kartor, studie av de analytiska signlar hos magnetiska och gravimetriska data, data processering, potential fält- och 3D modellering samt tolkningen av ovannämnda modeller. Baserat på den observerade samt modellerade datan har en veck strucktur upptäckts i koppling till Mertainen, och flertalet mineraliseringar tros vara strukturellt relaterade till detta veck. Dessutom har en potentiell mineralisering strukturellt relaterad till vecket upptäckts, dock är det väldigt troligt att den inte är ekonomiskt brytbar.
Miles, Warner Frederick. "An interpretation of high resolution aeromagnetic data over the Manitouwadge greenstone belt, Ontario, Canada." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0005/MQ36726.pdf.
Повний текст джерелаReynolds, Scott. "A gravity and aeromagnetic investigation of sub-surface granitoids in the Pine Creek geosyncline /." Abstract and contents only, 1997. http://web4.library.adelaide.edu.au/theses/09SB/09sbr465.pdf.
Повний текст джерелаTaib, Samsudin Hj. "Interpretation of the aeromagnetic anomalies of mainland Scotland using pseudogravimetric transformation and other methods." Thesis, Durham University, 1990. http://etheses.dur.ac.uk/6076/.
Повний текст джерелаVallejos, Luis E. Santamaria. "Three-dimensional analysis of aeromagnetic and gravimetric data of sedimentary basins from Panama, Central America." Licentiate thesis, Luleå tekniska universitet, Geovetenskap och miljöteknik, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-18258.
Повний текст джерелаGodkänd; 2008; 20080602 (ysko)
Markham, Stephen L. "The application of high resolution aeromagnetic surveys to petroleum exploration in the Western Otway Basin /." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09SM/09smm345.pdf.
Повний текст джерелаOne compact disc in pocket on back end paper. System requirements for accompanying computer CD-ROM: Mackintosh or IBM-compatible computer. Other requirements: Microsoft Word 6 or compatible Word Processor, or Postscript file viewer. Includes bibliographical references (leaves 183-197).
Santamaria, Vallejos Luis E. "Three-dimensional analysis of aeromagnetic and gravimetric data of sedimentary basins from Panama, Central America /." Luleå : Luleå University of Technology, 2008. http://epubl.ltu.se/1402-1757/2008/24/.
Повний текст джерелаHaidarian, Mohammad Reza. "Aeromagnetic interpretation of a section of the Willyama Inliers in the Curnamona Craton, South Australia /." Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phh149.pdf.
Повний текст джерелаLeonard, Mark. "Interpretation of an aeromagnetic survey over a shallow sedimentary basin with particular emphasis on spectral analysis /." Title page, contents and abstract only, 1986. http://web4.library.adelaide.edu.au/theses/09SB/09sbl581.pdf.
Повний текст джерелаBeinke, Lynelle Marie. "Applications of three component aeromagnetic data to iron ore exploration in the Hamersley Basin, Western Australia /." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09SB/09sbb4228.pdf.
Повний текст джерела"November 1997" The potential applications of three component aeromagnetic data in iron ore exploration have been investigated through forward model study and the interpretation of real data from the Hamersley Basin. The use of three component aeromagnetic data for iron ore exploration in the future has been recommended.
Barker, Kelly. "Improved application of remote referencing data in aeromagnetic processing : insights and applications from global geomagnetic modelling." Thesis, University of Liverpool, 2016. http://livrepository.liverpool.ac.uk/3002173/.
Повний текст джерелаHarvey, Leslie M. "Examination of an aeromagnetic anomaly over the Talisker Mine area on the southern Fleurieu Peninsula, South Australia /." Title page, contents and abstract only, 1989. http://web4.library.adelaide.edu.au/theses/09SB/09sbh342.pdf.
Повний текст джерелаBranch, Thomas Cameron. "Electrical conductivity experiments on carbon-rich Karoo shales and forward modelling of aeromagnetic data across the Beattie Anomaly." Thesis, Nelson Mandela Metropolitan University, 2014. http://hdl.handle.net/10948/d1014544.
Повний текст джерелаAnderson, Eric D. "Aeromagnetic signature of the geology and mineral resources near the pebble porphyry cu-au-mo deposit, southwest Alaska." Thesis, Colorado School of Mines, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3602616.
Повний текст джерелаAeromagnetic data are used to better understand the geology and mineral resources near the Late Cretaceous Pebble porphyry Cu-Au-Mo deposit in southwestern Alaska. The reduced-to-pole (RTP) transformation of regional-scale aeromagnetic data show that the Pebble deposit is within a cluster of magnetic anomaly highs. Similar to Pebble, the Iliamna, Kijik, and Neacola porphyry copper occurrences are in magnetic highs that trend northeast along the crustal-scale Lake Clark fault. A high-amplitude, short- to moderate-wavelength anomaly is centered over the Kemuk occurrence, an Alaska-type ultramafic complex. Similar anomalies are found west and north of Kemuk. A moderate-amplitude, moderate-wavelength magnetic low surrounded by a moderate-amplitude, short-wavelength magnetic high is associated with the gold-bearing Shotgun intrusive complex. The RTP transformation of the district-scale aeromagnetic data acquired over Pebble permits differentiation of a variety of Jurassic to Tertiary magmatic rock suites. Jura-Cretaceous basalt and gabbro units and Late Cretaceous biotite pyroxenite and granodiorite rocks produce magnetic highs. Tertiary basalt units also produce magnetic highs, but appear to be volumetrically minor. Eocene monzonite units have associated magnetic lows. The RTP data do not suggest a magnetite-rich hydrothermal system at the Pebble deposit. The 10 km upward continuation transformation of the regional-scale data shows a linear northeast trend of magnetic anomaly highs. These anomalies are spatially correlated with Late Cretaceous igneous rocks and in the Pebble district are centered over the granodiorite rocks genetically related to porphyry copper systems. The spacing of these anomalies is similar to patterns shown by the numerous porphyry copper deposits in northern Chile. These anomalies are interpreted to reflect a Late Cretaceous magmatic arc that is favorable for additional discoveries of Late Cretaceous porphyry copper systems in southwestern Alaska. Aeromagnetic data help to understand the three-dimensional distribution of plutonic rocks near the Pebble porphyry copper deposit. Magnetic susceptibility measurements show that rocks in the Pebble district are more magnetic than rocks of comparable compositions in the Pike Creek-Stuyahok Hills volcano-plutonic complex. The reduced-to-pole transformation of the aeromagnetic data demonstrates that the older rocks in the Pebble district produce strong magnetic anomaly highs. The tilt derivative transformation highlights a strong, northeast-trending structural grain attributed to Tertiary volcanic rocks. Multiscale edge detection maps near-surface magnetic sources that are mostly outward dipping and coalesce at depth in the Pebble district. The total horizontal gradient of the 10 km upward continued magnetic data map a circular, deep magnetic contact along which the porphyry deposits occur. Forward and inverse magnetic modeling show that the magnetic rocks in the Pebble district extend to depths greater than 9 km. The magnetic inversion is constrained by a near-surface, three-dimensional geologic model that is attributed with measured magnetic susceptibilities from various rock types in the region. The inversion results indicate that several near-surface magnetic features with moderate susceptibilities converge with depth into magnetic bodies with higher susceptibilities. This deep magnetic source appears to rise towards the surface in several areas. An isosurface value of 0.02 SI is used to depict the magnetic contact between outcropping granodiorite and non-magnetic sedimentary host rocks. The contact is shown to be outward dipping. At depths around 5 km nearly the entire model exceeds the isosurface value indicating the limits of non-magnetic host material. The inversion results show the presence of a relatively deep, northeast trending magnetic low that parallels lineaments mapped by the tilt derivative. This deep low represents a strand of the Lake Clark fault. The geodynamic setting of an accreted island-arc terrane represent a region in which several types of mineral resources may occur. The mineral resources from southwest Alaska are classified into greenstone-hosted, oxidized intrusion-related, reduced intrusion-related, and epithermal. Aeromagnetic data are related to the classified mineral resource and outcropping geology to better understand the distribution of gold-rich mineral resources. Three magnetic domains are defined by the reduced-to-pole, upward continue, and tilt derivative transforms. The greenstone-hosted mineral resources that include VMS are mapped along magnetic lineaments mostly landward of the accreted island-arc. The oxidized intrusion-related mineral resources that include porphyry copper, skarn, and Alaska-type ultramafic-mafic complexes occur along magnetic anomaly highs in the Peninsular and Kahiltna domains. Characteristic short wavelength, high amplitude magnetic anomalies suggest additional Alaska-type ultramafic-mafic complexes and skarn resources in the Kahiltna and Kuskokwim domain. Magnetic depth estimates indicate potential greenstone-hosted and oxidized intrusion-related resources occur beneath 100 m of glacial deposits. Reduced intrusion-related resources are best imaged in the more landward, Kuskokwim magnetic domain. Epithermal resources are not well imaged. The mineral potential map highlights areas most favorable for additional mineral resources.
Stokes, Terence Michael. "An investigation of ground based and aeromagnetic data over the Cairngorm and other Caledonian granites in the UK." Thesis, Open University, 1994. http://oro.open.ac.uk/57502/.
Повний текст джерелаDutra, Alanna Costa. "\"Estudo de anomalias gravimétricas e aeromagnéticas das alcalinas morro de engenho e A2, sudoeste de Goiás\"." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/14/14132/tde-12032007-164243/.
Повний текст джерелаThe Alkaline Province Rio Verde - Iporá, in the north border of the Paraná Basin is characterized by the presence of alkaline intrusions with strong gravity and magnetic signature. This project implemented a gravity survey in the Southwest of Goiás, including a detail one on Morro do Engenho Complex (ME), and one a few kilometers towards NE from ME over an aeromagnetic anomaly known as A2, and over a gravity anomaly close to Britânia city. ME and A2 have magnetic anomaly. The gravity anomalies vary from 15 to 30 mGal in relation to the regional gravity field, while the magnetic anomalies are of the order ±3000nT. Measurements of petrophysical properties of samples from the area were also done. The results present the inversion of the gravity and magnetic data, suggesting that the bodies are inside of the superior crust until the maximum depth of 10 km, in a cylindrical form with 8 to 10 km in diameter. 2.5D direct modeling was also done for ME including remanent magnetization and was performed at the two data sets together, the obtained results indicate that the close volume of the anomalous body it is 980 km3.
Basford, Paul W. "Investigation of isolated aeromagnetic anomalies in the Kimba region of South Australia, using magnetic, gravity and induced polarization methods /." Title page, contents and abstract only, 1992. http://web4.library.adelaide.edu.au/theses/09SB/09sbb299.pdf.
Повний текст джерелаOn title page : "National Grid reference : Kimba Sheet s1 53-7(1:250 000) Whyalla Sheet S153-8(1:250 000) Yardea Sheet S153-3(1:250 000)." Includes bibliographical references (leaves 22-24).
Nnange, Joseph Metuk. "The crustal structure of the Cameroon Volcanic Line and the Foumban Shear Zone based on gravity and aeromagnetic data." Thesis, University of Leeds, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305782.
Повний текст джерелаSamson, Esuene M. A. "A critical evaluation of the "Tilt-Depth" method of magnetic data interpretation : application to aeromagnetic data from North Eastern (NE) Nigeria." Thesis, University of Leeds, 2012. http://etheses.whiterose.ac.uk/4925/.
Повний текст джерелаSunderland, Andrew. "Characterising and improving a magnetic gradiometer for geophysical exploration." University of Western Australia. School of Physics, 2009. http://theses.library.uwa.edu.au/adt-WU2010.0111.
Повний текст джерелаPereira, Janaína Gattermann. "Contribuição ao estudo geológico da Bacia do Camaquã – RS, através de modelagem aeromagnética 2,5D." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/56294.
Повний текст джерелаThe Camaquã Basin (CB) is an important geologic unit and the knowledge of these rocks helps to clarify the geotectonic evolution of Rio Grande do Sul State. It has partially preserved different volcano-sedimentary associations representing the transition stage of South American Platform. The rocks of the basin overlays the igneous and metamorphic terrains of the Sul-riograndense Shield and its stratigraphic and geochronologic evolution have been widely studied by several authors. On the other hand, the geophysics has a small contribution to these studies, in despite of its great potential as an exploratory tool. Therefore, with the improvement of the data processing techniques, a new approach was applied in the aeromagnetic survey, acquired in 1972 by Brazilian Geological Survey. In this context, this research aims to contributes to the geologic and tectonic knowledge of the basin. The reprocessing of these variables led to the reinterpretation of the CB and to the production of a suggested model for its structural framework. Thematic maps and a 2,5D model of the CB were made from aeromagnetic data of a NW-SE section, with 40 km long, located in the south of the basin. These thematic aeromagnetic maps set out the main bodies and structures inside the basin and also provide a division of the study area into three main geophysics domains: West, Central and East, separated by the Magnetic Anomaly of Caçapava do Sul and the Dorsal de Canguçu Shear Zone, respectively. The 2,5D aeromagnetic modeling shows anomalies between -40 e -110nT, associated with volcanic and metamorphic outcropping rocks and the crystalline basement in subsurface, modeled at a maximum deep of 7000m in the NW portion of the section. In terms of geotectonic, the model obtained for this section revealed extensional faults, suggesting a sketch that resembles a horst and graben structure. This structure is typical for a rift system, assigning a distensive strain event in the evolution of the CB. The model also displayed two basement uplifts on the section borders, related with Caçapava do Sul and Serra das Encantadas uplifts. This uplift of the basement on section borders and its flexural behavior in the central portion can be an evidence of a compressive regime that occurred before the rift process and the sedimentation of the Camaquã Basin. The low susceptibility of the sediments that fill the basin is an indicative that the source areas can be the highs of Caçapava do Sul and Serra das Encantadas, composed mainly by low susceptibility granitic and gneissic rocks. The reprocessing of the geophysical variables, together with the frequency filters applied and the geophysical modeling, proved to be an efficient technique to the geologic mapping and to define the structural framework of the area. Based on this, a geologic model was created, which represents a specific portion of the basin and introduced an important knowledge of the structural framework and geotectonic evolution of the Camaquã Basin.
Baptiste, Julien. "Cartographie structurale et lithologique du substratum du Bassin parisien et sa place dans la chaîne varisque de l’Europe de l’Ouest : approches combinées géophysiques, pétrophysiques, géochronologiques et modélisations 2D." Thesis, Orléans, 2016. http://www.theses.fr/2016ORLE2052/document.
Повний текст джерелаMapping the cadomian/variscan basement buried beneath the Paris basin is a key objective to improve the geological knowledge of the Variscan belt in West Europe. We address this objective using a combination of new and updated potential field data (aeromagnetic and gravity), as well as information provided by field studies and drill cores, and a library of petrophysical characteristics measured on field samples. On a large southern half of the Paris basin, from the Armorican Massif to the Vosges: i) we made a new interpretative structural sketch map under the sedimentary cover, ii) we proposed a detailed geological map of the Paris basin substratum, iii) we updated the tectonic sketch of the Variscan belt in France, supported by new geochronological determinations on deep drill cores. Altogether, these results show that the eo-Variscan suture is extended from the southern part of the Armorican Massif to the northern Vosges. Eastwards, the North-Armorican domain reaches the Bray fault; and the Saxothuringian zone is extended from the Vosges to the English Channel. In addition, based on combined aeromagnetic and gravity 2D modelling constrained by Couy deep borehole data, the PBMA source is interpreted as a deep intermediate-alkaline plutonic body. Finally, compiling bibliographic information together with our new results, we hypothesize that this magmatic body could have been emplaced in the early to late Visean period, during a NNE-SSW opening under a NNW-SSE shortening
Le, Maire Pauline. "Caractérisation des anomalies magnétiques, approches théoriques et expérimentales : applications à des objets anthropiques et géologiques." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAH006/document.
Повний текст джерелаMagnetic anomalies recorded outside bodies provide high quality information relative to buried structures. By using theoretical and experimental developments, this thesis aims to improve the characterization of the source inducing the magnetic anomaly. Firstly, some properties of three dimensional magnetic functions are presented, for example the presence of several maxima of the analytic signal operator (3D) is demonstrated. The Nabighian (1972) equation is generalized, which imply a new process to study potential method in two dimensions. These developments enable a new visualization of the anomaly in the complex field. The second approach is experimental. Synthetic cases are used to estimate the contribution of different configurations of magnetic data acquisitions at different altitudes to characterize the magnetic source. Theoretical and experimental developments are finally applied to two field examples: oceanic magnetic anomalies and archaeological magnetic prospection
Hahne, Kai. "Detektion eines mesozoischen Gangschwarmes in NW Namibia und Rekonstruktion regionaler Spannungszustände während der Südatlantiköffnung." Phd thesis, Universität Potsdam, 2004. http://opus.kobv.de/ubp/volltexte/2005/177/.
Повний текст джерелаDas Arbeitsgebiet im namibianischen Henties Bay-Outjo Dike swarm (HOD) war zur Zeit der Unterkreide einem Rifting mit intensiver Platznahme von überwiegend mafischen Gängen unterworfen. Geochemische Signaturen weisen die Gänge als erodierte Förderkanäle der Etendeka Plateaubasalte aus. Durch den Einsatz von hochauflösenden Aeromagnetik- und Satellitendaten war es möglich, die Geometrie des Gangschwarmes erstmals detailliert synoptisch zu erfassen. Viele zu den Schichten des Grundgebirges foliationsparallel verlaufende magnetische Anomalien können unaufgeschlossenen kretazischen Intrusionen zugeordnet werden.
Bei der nach Norden propagierenden Südatlantiköffnung spielte die unterschiedliche strukturelle Vorzeichnung durch die neoproterozoischen Faltengürtel sowie Lithologie und Spannungsfeld des Angola Kratons eine bedeutende Rolle. Im küstennahen zentralen Bereich war dank der Vorzeichnung des Nordost streichenden Damara-Faltengürtels ein Rifting in Nordwest-Südost-Richtung dominierend, bis das Angola Kraton ein weiteres Fortscheiten nach Nordosten hemmte und die Vorzeichnung des Nordwest streichenden Kaoko-Faltengürtels an der Westgrenze den weiteren Riftverlauf und die letztendlich erfolgreiche Öffnung des Südatlantiks bestimmte. Aus diesem Grund kann das Gebiet des HOD als ein failed rift betrachtet werden.
Die Entwicklung des Spannungsfeldes im HOD kann folgendermaßen skizziert werden:
1. Platznahme von Gängen bei gleichzeitig hoher Dehnungsrate und hohem Magmenfluß.
2. Platznahme von Zentralvulkanen entlang reaktivierter paläozoischer Lineamente bei Abnahme der Dehnungsrate und fortbestehendem hohen Magmenfluß.
3. Abnahme/Versiegen des Magmenflusses und neotektonische Bewegungen führen zur Bildung von Halbgräben.
Dike swarms play a fundamental role in understanding continental breakup. On the one hand they represent strain markers of the paleo-deformation field and help to reconstruct the structural evolution of the rifted lithosphere. On the other hand their magmatic infill contains information about the conditions of magma generation, ascent and emplacement. Finally, dating of dikes allows reconstructing a chronological order of magmatic and structural events. The study area of the Namibian Henties Bay-Outjo Dike swarm (HOD) underwent tectonic extension in the Lower Cretaceous associated with the widespread emplacement of predominantly mafic dikes and intrusive ring complexes representing the remnants of volcanic centres. Geochemical signatures of the dikes prove them to be the feeder structures of the Etendeka Plateau Basalts. The application of recent high resolution aeromagnetic surveys and satellite imaging revealed the dike swarm's extent and geometry for the first time. The distribution and geometry of the dikes shown in the aeromagnetics reflect the propagation of the South Atlantic opening from south to north by their relative-ages.
Northwest-southeast-directed rifting was dominant in the central coastal area, due to the structural control of the northeast striking basement structures until further propagation was hampered by the Angola Craton. Subsequently the structural control of the coast-parallel Kaoko Belt became dominant and determined the successful opening of the South Atlantic. Hence, the area of the HOD can be considered as a failed rift.
The stress field evolution within the HOD can be outlined as follows:
1. Intrusion of dikes when extension rates as well as magma supply were high.
2. Intrusion of volcanic ring complexes along reactivated Panafrican lineaments when extension rates decreased and magma supply remained high.
3. Neotectonic movements create half-grabens after the termination of magmatism.
Potie, Gilbert. "Contribution à l'étude géologique de la frontière SE de la plaque caraibe : la serrania del interior oriental sur le transect Cumana-Urica et le bassin de Maturin (Vénézuela) : application de données géophysiques et géologiques à une interpretation structurale." Brest, 1989. http://www.theses.fr/1989BRES2005.
Повний текст джерелаInkster, D. H. "Filtering aeromagnetic data to reduce the masking effect of near-surface basalt." Thesis, 1995. http://hdl.handle.net/2440/88300.
Повний текст джерелаThis project investigated two areas in northern Queensland where Tertiary basalt covers igneous and metamorphic rocks considered prospective for gold. The moderate to high magnetic susceptibility of the basalt, combined with variations in its thickness, give a high degree of variability to the aeromagnetic data which impedes interpretation of deeper structures. Low-pass filters of the Butterworth, averaging-window and median-window types were used initially, because the near-surface signals tends to be higher in spatial frequency. Upward continuation was also used. All were able to remove high frequencies but none showed a clear superiority at simultaneously resolving detail. The best results eventually were obtained from a differencing method in which the high-frequency signals were first emphasised by downward continuation and then subtracted from the original signal. This enabled identification of several features which had not been visible in either the original, or low-pass-filtered data. The differencing method is shown to be equivalent to subtracting the first vertical derivative (multiplied by a scaling factor) from the total magnetic intensity. The generality of this approach was then tested by applying it to another dataset with different sampling and geological parameters. The resolution available in the second case is limited by the 400m flight line spacing, instead of the 200m of the first dataset. The results were less successful but there is evidence that the approach is still valid.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Earth and Environmental Sciences, 1995
Harvey, L. M. "Examination of an aeromagnetic anomaly over the Talisker Mine area on the southern Fleurieu Peninsula, South Australia." Thesis, 1989. http://hdl.handle.net/2440/119293.
Повний текст джерелаA N-E striking elongate aeromagnetic anomaly is observed over the Talisker Mine area, on the southern Fleurieu Peninsula, which has character and amplitude similar to an anomaly observed at Delamere (several kilometres to the north) found to be caused by magnetic Brachina Formation. Geological and geophysical techniques have been used to determine if the rock type at Talisker is also magnetic Brachina Formation, why there is a gap between the two anomalies, and why the anomaly at Talisker ends near the south coast. Geological mapping, microscopy and petrologic studies have been used in conjunction with local ground magnetic surveys and modelling procedures, to reveal magnetic Brachina Formation as the cause of the anomaly at Talisker. Mapping has shown the anomaly to be the result of a sliver of magnetic Brachina Formation caught up within a local zone of intense deformation that extends for at least 1500m across strike, and which outcrops on the coast. The Brachina Formation is sheared out against Cambrian Backstairs Passage Formation to the south, forming the southern end to the anomaly. To the north, the Brachina Formation suffered deeper erosion during Permian times, and is covered by a greater thickness of non-magnetic cover which causes the apparent gap in the aeromagnetic anomaly.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 1989
Odwar, Henry Dilah. "Combined MAGSAT and aeromagnetic investigation of the Alpha Ridge crust." 1993. http://hdl.handle.net/1993/17767.
Повний текст джерелаRajagopalan, Shanti. "Aeromagnetic interpretation of the Kanmantoo Group, South Australia / Shanti Rajagopalan." 1989. http://hdl.handle.net/2440/19036.
Повний текст джерелаBibliography: leaves 115-128.
xi, 128 leaves : ill., maps (some col.), 1 folded ; 30 cm. + 2 microfiche, 5 maps (folded), appendix and errata in pocket inside back cover.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Thesis (Ph.D.)--Dept. of Geology and Geophysics, University of Adelaide, 1989
Hitchman, Adrian P. "Interactions between aeromagnetic data and electromagnetic induction in the earth." Phd thesis, 1999. http://hdl.handle.net/1885/147975.
Повний текст джерелаRajagopalan, Shanti. "Aeromagnetic interpretation of the Kanmantoo Group, South Australia / Shanti Rajagopalan." Thesis, 1989. http://hdl.handle.net/2440/19036.
Повний текст джерелаxi, 128 leaves : ill., maps (some col.), 1 folded ; 30 cm. + 2 microfiche, 5 maps (folded), appendix and errata in pocket inside back cover.
Thesis (Ph.D.)--University of Adelaide, Dept. of Geology and Geophysics, 1989
Dhu, Trevor. "The use of fractal dimension for texture-based enhancement of aeromagnetic data." 2008. http://hdl.handle.net/2440/49982.
Повний текст джерелаhttp://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1339560
Thesis (Ph.D.) - University of Adelaide, Australian School of Petroleum, 2008
Dhu, Trevor. "The use of fractal dimension for texture-based enhancement of aeromagnetic data." Thesis, 2008. http://hdl.handle.net/2440/49982.
Повний текст джерелаThesis (Ph.D.) - University of Adelaide, Australian School of Petroleum, 2008