<p>With an ever-increasing consumption of natural resources new prospecting techniques are required to satisfy the demand. Geophysical methods are one tool commonly relied upon. New acquisition platforms or survey methodologies provide one way to expand the geophysical capabilities, but are expensive and slow to develop. New processing and interpretation techniques on the other hand provide a rapid means to reinterpret existing datasets with the goal of improving our geologic understanding of a project area. This thesis presents four new ways to extract additional geologic insights from a variety of geophysical datasets. All of the studies are based within the Bathurst Mining Camp, NB.</p> <p>A physical rock property database for the Bathurst Mining Camp is constructed and statistically analyzed in chapter two. Descriptive statistics include mean, standard deviation; first, second and third quartiles are calculated for density and magnetic susceptibility measurements and provided in tables for reference. Bivariate plots are then used to identify trends in the density-magnetic susceptibility relationship. We relate some of our findings to processes involved in the depositional and alteration history of the various lithologies. Comprehensive rock property databases provide valuable constraints for geophysical data processing and are essential for any subsequent geophysical modeling. This is demonstrated with two examples. A joint gravity-magnetic profile model is completed across the geologically complex Nine Mile Synform. The profile reveals deep structure in the Camp down to 5 km depth. A geologically constrained geophysical inversion model of the magnetic anomaly associated with the Armstrong B mineral deposit reveals this anomaly contains a strong magnetic remanence contribution. The influence of remanence is often ignored in magnetic interpretation and modeling, but vital to achieve a geologically correct solution. In this instance comparison of the calculated remanence direction with the expected Apparent Polar Wander Path defined direction suggests an age of mineralization that is compatible with geological evidence.</p> <p>A new approach to determine the optimum near surface residual magnetic signal is presented in chapter three. Additionally, a new way of locating remanently magnetized bodies is also introduced. This technique inverts frequency domain helicopter-borne electromagnetic data to yield apparent magnetic susceptibility. To locate those zones where the magnetic signal is dominated by remanence the inverted HFEM susceptibility is cross plot against the results of a traditional apparent susceptibility filter. The inverted HFEM susceptibility is independent of remanence while the apparent susceptibility assumes no remanence. Where remanence is present the TMI derived apparent susceptibility does not correlate with the HFEM. These differences are readily evident in a cross plot of the two susceptibilities. To determine a magnetic residual the inverted susceptibility is forward modeled as a series of vertical prisms with homogeneous susceptibility equal to the inverted susceptibility. This HFEM magnetic model is then used to reference the results of traditional wavelength separation methods. By design the HFEM information is restricted the near surface whereas all traditional regional / residual separation methods operate under wavelength assumptions. A case study using this methodology is presented on the western side of the Tetagouche Antiform.</p> <p>The use of a spatially variable density correction applied to ground gravity and gravity gradiometry in the BMC is examined in the fourth chapter. The influence of topography on gravity and gravity gradiometry measurements is profound and must be removed prior to interpretation. In geologic environments where there is a structural and/or stratigraphic control on the near surface mass distribution, using a single density value may introduce error into the reduced data. A regionally variable density correction is a means to compensate for this effect. Spectral information between the ground gravity and airborne gravity gradiometry is also compared in this chapter. Both systems are fundamentally recording the same geologic mass distribution albeit by different means. Where differences exist one system must be in error.</p> <p>The final chapter demonstrates a quantitative interpretative technique for geophysical data. Often interpretation of the geophysical data in a geological context is done qualitatively using total field and derivative maps. With this approach the resulting map product may reflect the interpreter’s bias. Source edge detection provides a quantitative means to map lateral physical property changes in potential and non-potential field data, but the field data must be transformed prior to SED computation. There are numerous transformation algorithms, all of which operate slightly differently. We demonstrate that by combining the output of several different SED computations through data stacking, the interpretable product of SED is improved. In two examples, a synthetic example and real world example from the Bathurst Mining Camp, a number of transformation algorithms are applied to gridded geophysical datasets and the resulting SED solutions combined. Edge stacking combines the benefits and nuances of each SED algorithm; coincident, or overlapping solutions are considered more indicative of a true edge, while isolated points are taken as being indicative of random noise or false solutions.</p> / Master of Science (MSc)

Efficient data integration is one of the most challenging problems in data management, interoperation and analysis. The Earth science data which are heterogeneous are collected at various geographical locations for scientific studies and operational uses. The intrinsic problem of archiving, distributing and searching such huge scientific datasets is compounded by the heterogeneity of data and queries, thus limiting scientific analysis, and generation/validation of hydrologic forecast models. The data models of hydrologic research communities such as National Weather Service (NWS), National Oceanic and Atmospheric Administration (NOAA), and US Geological Survey (USGS) are diverse and complex. A complete derivation of any useful hydrological models from data integrated from all these sources is often a time consuming process. One of the current trends of data harvesting in scientific community is towards a distributed digital library initiative. However, these approaches may not be adequate for data sources / entities who do not want to "upload" the data into a "data pool." In view of this, we present here an effective architecture to address the issues of data integration in such a diverse environment for hydrological studies. The heterogeneities in these datasets are addressed based on the autonomy of data source in terms of design, communication, association and execution using a hierarchical integration model. A metadata model is also developed for defining data as well as the data sources, thus providing a uniform view of the data for different kind of users. An implementation of the model using web based system that integrates widely varied hydrology datasets from various data sources is also being developed. / Master of Science

Ophiolites - thrust sheets of oceanic lithosphere that have been emplaced onto the continental margin - provide the opportunity to explore the structure and genesis of oceanic crust. As many ophiolites formed above subduction zones, they also allow for the investigation of mantle wedge and subduction interface processes. This the- sis examines the Oman-United Arab Emirates (UAE) ophiolite, which is the largest and most intensely studied ophiolite on Earth. Three distinct problems are addressed. (1) Recent research has proposed that the architecture and tectonic evolution of the ophiolite in the UAE differs from in Oman. In Chapter 2, I test this hypothesis by integrating new geological mapping and field observations with previously published maps of the ophiolite in the UAE. My results indicate that the ophiolite is gently folded, but otherwise largely intact. I demonstrate that the architecture of the ophi- olite in the UAE is not significantly different from in Oman. Thus, there is no basis for a different tectonic evolution as recently proposed. (2) Observations from exper- iments and small-scale natural shear zones indicate that volumetrically-minor phases can control strain localization. In Chapter 3, I test the hypothesis that minor phases control strain-localisation at plate boundaries. To do so, I analyzed peridotites from the base of the ophiolite, a palaeosubduction interface. My results demonstrate that minor phases limited olivine grain growth, which led to rheological weakening. (3) The mechanisms by which metamorphic soles detached from the downgoing slab and accreted to the hanging-wall mantle is unclear. In Chapter 4, I examine a transect across the metamorphic sole in the UAE. My results reveal that granulite formation was more extensive than is typically considered. I propose that granulite formation resulted in rheological strengthening, which caused the subduction interface to migrate into the downgoing slab and accrete the metamorphic sole.

abstract: Climate change is not a thing of the future. Indigenous people are being affected by climate changes now. Native American Earth scientists could help Native communities deal with both climate change and environmental pollution issues, but are noticeably lacking in Earth Science degree programs. The Earth Sciences produce the lowest percentage of minority scientists when compared with other science and engineering fields. Twenty semi-structured interviews were gathered from American Indian/ Alaska Native Earth Scientists and program directors who work directly with Native students to broaden participation in the field. Data was analyzed using qualitative methods and constant comparison analysis. Barriers Native students faced in this field are discussed, as well as supports which go the furthest in assisting achievement of higher education goals. Program directors give insight into building pathways and programs to encourage Native student participation and success in Earth Science degree programs. Factors which impede obtaining a college degree include financial barriers, pressures from familial obligations, and health issues. Factors which impede the decision to study Earth Science include unfamiliarity with geoscience as a field of study and career choice, the uninviting nature of Earth Science as a profession, and curriculum that is irrelevant to the practical needs of Native communities or courses which are inaccessible geographically. Factors which impede progress that are embedded in Earth Science programs include educational preparation, academic information and counseling and the prevalence of a Western scientific perspective to the exclusion of all other perspectives. Intradepartmental relationships also pose barriers to the success of some students, particularly those who are non-traditional students (53%) or women (80%). Factors which support degree completion include financial assistance, mentors and mentoring, and research experiences. Earth scientists can begin broaden participation by engaging in community-inspired research, which stems from the needs of a community and is developed in collaboration with it. Designed to be useful in meeting the needs of the community, it should include using members of the community to help gather and analyze data. These community members could be students or potential students who might be persuaded to pursue an Earth Science degree. / Dissertation/Thesis / Ph.D. Curriculum and Instruction 2011

The continental crust is the record of the history of the Earth, of the processes and events that have contributed to the planet's evolution. It is now understood that the continental crust is growing continuously since the early ages of the Earth. Archean-Proterozoic boundary marks one of the major transition periods in the crustal evolution processes. However, there are only few crustal remnants available to investigate this milestone of Earth history, reported with significant chemical discontinuity. The Neoarchean crustal fragments of southern India provide a window to probe the processes that happened during such transitions. The geology of southern India can be broadly divided in to the Archean Dharwar Craton (DC) of granites and greenstones belts to the north and an assembly of crustal blocks experienced granulite grade metamorphism to the south from Archean to Neoproterozoic, namely the Southern Granulite Terrain (SGT). The relationship between DC and SGT terranes are not well established, primarily due to lack of studies on the growth and evolution on each of the crustal blocks. This study focuses on the crustal tract between Salem Attur Shear Zone and the Cauvery Shear Zone of the SGT. This region lies to the east of Palghat Cauvery Shear System, which is considered as dextral shear zone, suture zone, Neoproterozoic terrain boundary and reworked Archean crust in the previous studies. However, so far no comprehensive studies had been reported from the region that consists of a spectrum of rocks charnockite, granitic gneiss, hornblende gneiss, granite and mafic-ultramafics litho-units inclusive of a layered complex. The objectives of this study are 1) to understand the crustal formation processes in Kolli-massif 2) to delineate the chronology of events or processes through radiometric dating. 3) to understand the crustal reworking and evolutionary processes in Kolli-massif . Major tools used in this study include petrology (field studies and petrography), geochemistry, U-Pb Zircon geochronology, Sr-Nd and Hf Isotopes. The content of this thesis is divided in to six chapters. Chapter 1 is an introduction to the topic – crustal growth. It discusses the importance of continental crustal process in understanding the evolutionary history of the 2500 Ma Earth. It also emphasizes on the reason to investigate Kolli-massif which is a part of the Southern Granulite Terrain. Chapter 2 deals with the literature review which is relevant in the context of the study. The chapter discusses topics like structure of the Earth crust, various models proposed on the generation of continental crust (continuous as well as episodic) and also the models discussed in the literature on the generation of TTG (subduction of oceanic crust and ocean plateau and non-subduction). An overall view on crustal reworking and recycling is also included. The chapter ends with a short review on southern Indian crustal tectonics and a detailed discussion on the evolution Palghat Cauvery Shear Zone. Chapter 3 describes the geology of the study area Kolli-massif in details. This includes the structural, lithological units, field relation and geochronolgical aspects combined and their implications on the crustal assembly of southern India. Chapter 4 is a discussion on the results, interpretation and implications of crustal generation and evolution of the Archean Kolli-massif. This chapter is subdivided to four. Chapter 4.1 deals with possible source and tectonic settings for the magma generation which lead to the formation of Archean Sittampundi Complex. The whole rock and spinel chemistry two different suggests both MORB and arc signature for these rocks. Although this is such a quite contrasting scenario, such scenarios are known to occur in an intra-oceanic subduction in the Archean as well as modern analogue. The search for MOR setting lead to Kanjamalai, where major rocks like metagabbro show geochemical affinity, as described in Chapter 4.2. The presence of rocks like plagiogranite also supports MORB affinity. Based on field observations and above evidences Kanjamalai complex is interpreted as subducted remnant of an Archean Mid Oceanic Ridge. Chapter 4.3 deals with the major rock type of the region charnockite and granitic gneiss. The whole geochemical chemistry suggests arc signatures (depleted HFS elements, enriched LREE) and negative Nd and Hf isotope suggests reworked magma. However, the high HREE content and absence of Eu anomaly in the charnockite but reverse case of granitic gneiss indicates they might have of a different source and may not solely by the subduction of oceanic crust described in chapter 4.1. Combining the results from Hf and Nd isotopes that shows the presence of an older crust of age 2700-2900 Ma, it can be concluded that the an older oceanic crust, probably with an ocean plateau was part of subduction and magma genesis. The presence of garnet websterite describes accretion in operation in the generation of Kolli-massif. Chapter 4.4 deals with crustal recycling. The results on the investigation on meta-BIFs yielded results that can be interpreted that the iron formations were deeply subducted. The proposal of accretionary tectonics is also supported by the presence of meta-BIFs in the shear zone with in the Kolli-massif. Chapter 5 deals with the Neoproterozic reworking of the Archean Kolli-massif. The investigations on the sapphirine bearing granulite suggest that the rocks have undergone UHT metamorphism (6Kbar and 925˚C). The geochronogical evidences shows that the zircon rim growth ca. 550 Ma over a 2480 Ma crust. This suggests crustal reworking that would have happened during the Gondwana amalgamation happened during the Neoproterozoic time.It is therefore concluded in Chapter 6 that the Kolli-massif is having an Archean nucleus that was grown by the arc accretion. This reworked during the regional metamorphism along with the Gondwana metamorphism in the Neoproterozoic. Further scope of this study is also discussed.

Orientador: Silvia Fernanda de Mendonça Figueiroa / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-10T00:33:12Z (GMT). No. of bitstreams: 1 Alvim_MarciaHelena_D.pdf: 3691961 bytes, checksum: 179194dce27b8dccae8415e26823eefc (MD5) Previous issue date: 2007 / Resumo: Nesta pesquisa de doutorado nos dedicamos à análise do dialógo entre as fontes documentais Historia de los índios de la Nueva España, do frei Toríbio de Motolinia, Historia General de las cosas de la Nueva España, do frei Bernardino de Sahagún, e Historia Eclesiástica Indiana do frei Gerónimo de Mendieta, e a ciência natural do século XVI, em relação aos dois conjuntos temáticos propostos: a narrativa sobre o conhecimento dos corpos e fenômenos celestes e sobre o espaço e elementos naturais da superfície terrestre. Este também se apresenta como sendo nosso objetivo principal. Deste modo, em relação à hipótese principal desta pesquisa, acreditamos que o relato contido nas Historias missionárias reflete concepções estruturadas no panorama epistemológico europeu, com nítida herança conceitual medieval. O conhecimento deste período era formado por questões do mundo natural que se entrelaçavam aos elementos da religião cristã e às práticas reverenciadas pela tradição mágico-adivinhatória. Assim, ao apresentar o sistema cognitivo do século XVI, acreditamos esclarecer posições e atitudes dos relatos missionários aqui analisados que tradicionalmente são abordados por uma história que prioriza seus aspectos religiosos. Outra hipótese deste trabalho propõe que estas narrativas atenderam, ainda, aos objetivos pré-estabelecidos por seus autores, sendo estes fundamentados em seus respectivos projetos evangelizadores em relação às comunidades indígenas da Nova Espanha. Dentre as conclusões mais importantes quanto à análise das fontes documentais acerca do conhecimento sobre os corpos e fenômenos celestes e o cômputo temporal nahua, destacamos nestas narrativas a valorização do calendário sazonal em relação ao ciclo adivinhatório. A condenação ao Tonalpohualli se relacionou ao fato de este ter sido considerado uma arte adivinhatória, sendo apresentado pelos missionários como astrologia judiciária. A valorização do calendário sazonal indígena ainda se ateve a outros objetivos evangelizadores. O interesse na identificação das permanências idolátricas poderia encontrar um valioso instrumento, se as datas exatas das festividades pagãs fossem conhecidas pelos religiosos. Assim, o conhecimento deste cômputo teria a finalidade de estipular os dias das cerimônias religiosas indígenas com a intenção em averiguar sua permanência no período colonial. A partir da análise das Historias missionárias em relação à descrição da paisagem natural do Vale do México e dos elementos da superfície terrestre, averiguamos que os religiosos se interessaram por temas que se interligavam aos problemas cotidianos, como as inundações e o vulcanismo. O mundo natural foi apresentado a partir de concepções de cunho utilitário, providencial e organicista. Outro importante objetivo destas narrativas foi a busca por práticas que indicassem a permanência idolátrica nestas localidades. Quanto à descrição sobre os metais, pedras e fósseis notamos uma preocupação em apresentar suas propriedades terapêuticas, concepção esta pautada pelo universo mágico-adivinhatório europeu. O interesse pelo poder destes elementos em curar algumas enfermidades se conecta ao panorama histórico daquele período, pois muitas epidemias devastavam as populações americanas, atingindo também os espanhóis / Abstract: The main purpose of this doctorate research is to analyze the dialogue between the texts Historia de los indios de la Nueva España, by Friar Toríbio de Motolinia, Historia General de las cosas de Nueva España, by Friar Bernardino de Sahagún, and Historia Eclesiastica Indiana, by Friar Gerónimo de Mendieta, and natural science of XVI century, regarding the two subjects: the knowledge about the bodies and celestial phenomenal, included the nahua system calendar, and the analysis of the space and natural elements of the terrestrial surface. In this way, relation to the main hypothesis of this research, we believe that these Histories reflect conceptions based on the European knowledge of XVI century. This was formed for by elements of Christian religion and to the practical by the tradition magical-astrological. Thus, when presenting the knowledge of XVI century, we believe to clarify position and attitudes of the Histories missionaries which traditionally were studied and its religious aspects were prioritized. Another hypothesis of this work considers that these narratives are based on its respective evangelical project of these missionaries / Doutorado / Doutor em Ciências

A new Ph.D research project was started early October into the Department of Civil, Environmental and Natural Resources Engineering at Luleå University of Technology (LTU) by Sarah CONRAD under the direction of Johan INGRI. The part of this project in which I participed was the determination of the concentration of Fe (II) by flow injection analysis using chemiluminescence in the Bothnia Bay. The missions were to handle the instrument and the software and to prepare also some sample standards for the calibration of the FIA. The stream water is first sampled and filtered. Then the water, containing either just the natural iron in the water or after addition of artificial iron, is analyzed by flow injection analysis in combination with luminol. The results are saved on the laptop and interpreted later. The experiments were performed on both the field and the laboratory of the University. / <p>Validerat; 20131008 (global_studentproject_submitter)</p>

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