M.Sc. / This study has served to expand the geological map of surroundings of the Venetia Mine (Limpopo Province, South Africa) incorporating the area lying south of the kimberlite deposit and bounded in the south by the Dowe-Tokwe fault. The most significant structural conclusion stemming from this mapping project is that the Venetia Synform seems to be tectonically separate from the surrounding area and actually forms a klippe (shallowly dipping thrust) against the Krone Metamorphic terrane and the Gotha Complex. Petrographic descriptions of quartzofeldspathic lithologies found in the Krone Metamorphic Terrane to the west of the Venetia klippe (Mellonig, 2004) are identical suggesting that they belong to the Gotha igneous complex. There are no differences in geochemical compositions of monzogranite to granodiorite, tonalite and quartz diorite from Farms Gotha and Venetia. The rocks are I-type granitoids that generally form in continental magmatic arcs. The amount of U and Th in the igneous rocks of the Farms Gotha and Venetia (contained in minerals found within quartz, plagioclase, amphibole and K-feldspar crystal boundaries and the magmatic zircons of the Farm Gotha samples) and the pattern produced by heat producing elements (Council for Geoscience Radiogenic Map), indicate that that the unexpectedly high concentration of these elements are not the result of regional metamorphism, but is the remnant of the final crystallisation phase of the magma of the area. REE plots of the Venetia Mine samples show negative Eu anomalies, indicating the presence of plagioclase and K-feldspar in the magma source of the Venetia mine samples. The assumption is, that most samples retained their original chemical compositions having experienced only weak deuteric alteration and no dynamic metamorphism.

Orientador: Marcos Aurélio Farias de Oliveira / Banca: José de Araújo Nogueira Neto / Banca: Francisco de Assis Negri / Banca: Antenor Zanardo / Banca: Antonio Carlos Artur / Resumo: O presente trabalho apresenta os resultados de estudos petrográficos, geoquímicos, isotópicos e geotermobarométricos em rochas granulíticas, obtidos na região de Arceburgo - Santa Cruz da Prata (MG), dentro da Faixa Brasília e mais especificamente do Complexo Guaxupé. A geologia da área inclui metassedimentos representados por quartzitos foliados e rochas com intercalações de quartzo detrítico, associados a tipos da suíte charnockítica (charnockitos e alaskitos, charnockitos, álcali feldspato charnockito, granada gnaisse charnockito, enderbitos) além de granulitos tonalitos (máficos), biotita gnaisse com granada e biotita muscovita gnaisse. Essas rochas constituem faixas alongadas segundo a direção N600W, com ângulo de mergulho pequeno que varia entre 25 e 400, em média, para SW. As texturas predominantes são do tipo granoblástica ou mais freqüentemente blastomiloníticas, com quartzo e feldspato muito deformados e porfiroclastos de feldspato pertítico muito comuns, formando sigmóides. Os minerais essenciais são: feldspato potássico pertítico (mesopertita), plagioclásio (oligoclásio-andesina), hiperstênio, diopsídio, hornblenda marrom e biotita vermelha. A granada é observada apenas em litotipos como granada gnaisse charnockito, granulito tonalito (máfico) e biotita gnaisse com granada, localizados próximo a Zona de Cisalhamento Varginha. Diagramas ETRs e multielementos possibilitou a divisão das amostras em dois grupos geoquímicos que correspondem a duas assinaturas geoquímicas (crosta superior e crosta inferior) que podem ser interpretadas como conseqüência da geração e evolução dessas rochas em períodos e ambientes crustais de características distintas. Diagramas de classificação sugerem que a evolução do conjunto granulítico se deu partindo de composições mais... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This paper shows the results of petrographic studies, geochemical, and isotopic Geothermobarometry rocks in granulites, conducted in the region of Arceburgo - Santa Cruz de la Plata (MG), in the Brasilia Belt and more specifically the complex Guaxupé. The geology includes metasediments represented by quartzite and foliated rocks with intercalations of detrital quartz associated with types of the suite charnockites (charnockites e alaskites, charnockites, alkali feldspar charnockites, garnet gneiss, charnockites, enderbitos) as well as mafic tonalities granulites, biotite gneiss with garnet and biotite muscovite gneiss. These rocks are tracks elongated along the direction N600W, with small dip angle of between 25 and 40, on average, to SW. The textures are the predominant type granoblastic blastomiloníticas or more frequently, with quartz and feldspar and very deformed porfiroclastos feldspar perthite very common, forming sigmoid. The essential minerals are:feldspar perthite (mesopertita), plagioclase (oligoclase-andesite), hypersthene, diopside, hornblende and biotite red brown. The garnet is observed only in lithotypes charnockites and garnet gneiss, garnet enderbito gneiss and biotite gneiss with garnet, located near Varginha Shear Zone. ETRs and multi-element diagrams enabled the division of samples into two geochemical groups that correspond to two geochemical signatures (the upper crust and lower crust) can be interpreted as a consequence of the generation and evolution of rocks in crustal environments and periods with different characteristics. Classification diagrams suggest that the evolution of all Granulitic occurred starting with more basic compositions reaching acid compositions, probably due to processes Anatexia which points to the protolith rocks of basic composition... (Complete abstract click electronic access below) / Doutor

OpenStereo foi desenvolvido originalmente para preencher uma lacuna entre aplicativos de anáalise para geologia estrutural, como um software livre, gratuito e multi-plataforma. Ao longo dos anos ele adquiriu um grande núumero de usuários, com citações regulares. Este trabalho objetivou a reestruturação do OpenStereo como um todo, mudando-o para uma nova estrutura de interface gráfica e construíndo-o do zero visando desempenho, estabilidade e facilidade de manutenção e extensão. Diversas novas funcionalidades foram incluídas tais como projetos, conversão de notação de atitudes, ajuste de pequenos círculos, extração de atitudes de modelos tridimensionais e conversão de shapefiles de linhas para dados circulares. A pesquisa gerou dois subprodutos principais: um novo método gráfico para ajuste de pequenos círculos e a biblioteca de análise de dados estruturais Auttitude. / OpenStereo was originally developed to fill a gap among software packages for structural geology analysis, as a free open source cross-platform software. Over the years it has acquired a great number of users, with regular citations. This work aimed to restructure OpenStereo as a whole, changing to a new graphical interface framework and building it from the ground up for speed, stability, ease of maintenance and extension. Many new functionalities were also included, such as project management, structural attitudes notation handling, small circle fitting, extractions of attitudes from three-dimensional models and conversion of lines shapefiles to circular data. The research involved had two main byproducts, a new graphical method for small circle data fitting and a directional data analysis library, Auttitude.

Orientador: Norberto Morales / Banca: Antonio Roberto Saad / Banca: Maurício da Silva Borges / Neste trabalho é apresentado um estudo das relações existentes entre a ocorrência de depósitos sedimentares nos arredores de Jundiaí (SP) e o papel das falhas e fraturas na sua formação, deformação e preservação, objetivando a investigação de alguns eventos sucedidos na evolução cenozóica da região. Os métodos utilizados envolvem a extração de informações de bases cartográfkas, de fotografias aéreas e imagem de satélite; a obtenção de informações litoestratigrâficas para interpretações paleoambientais e a coleta de dados estruturais para o estudo do controle estrutural sobre os depósitos sedimentares, sobre a morfologia do terreno e para o cálculo de tensores. O embasamento pré-cambriano é composto basicamente por gnaisses com grau variável de migmatização e intercalações de quartzitos, xistos, anfibolitos, gonditos e metaultrabasitos incluídos no Complexo Amparo ou Itapira e, de forma mais restrita, filitos pertencentes ao Grupo São Roque. Intrusões granitóides são bastante comuns na regiao, predominando, na área, o Complexo Grauitóide Itu. Recobrindo o embasamento, aparecem depósitos paleozóicos correlacionados com o Grupo ttarai-é, constituídos por diamictitos, folhelhos, ritmitos, argilitos e siltitos. Estas rochas fonnam corpos isolados, embutidos no embasamento cristalino por falhas normais. Depósitos terciários, compostos por diamictitos, conglomerados, arenitos e argilitos também ocorrem sob a forma de corpos isolados, preservados pela presença de niveis conglomeráticos basais, mais resistentes à erosão, ou devido a falhamentos que ocasionaram abatimento e basculamento de blocos. São definidas nove fácies sedimentares formando associações que sugerem a existência de um antigo sistema de leques aluviais, sob clima semi-árido, cem área fonte na Sena do Japi...(Resumo completo, clicar acesso eletrônico abaixo) / AbstraThe existing relations between sedimentary deposits of the Jundiaí (SP) region and the role of faults and fractures in their formation, deformation and preservation are examined, with the aim to investigate the Cenozoic events which occurred in the region. The applied methodology includes cartographic information for examining terrain morphoogy accompanied to interpretation of aerial photographs and satellite imagery; lithostigraphic data for interpreting paleoenvironments and structural data for interpreting the structural control of sedimentary deposits, and tensor caiculations. The Precambrian basement of the area is composed of gneisses with variable degrees of migmatization as well as interlayers of quarzites, schists, amphibolites, gondites and metaultrabasics rocks included in the Amparo (or Itapira) Complex and, in a more restricted form, phyllites belonging to the São Roque Group. Granitic rocks are very common in the region, predominating the intrusions of the Itu Complex. Paleozoic deposits cover the basement, which are correlated with the Itararé Group, constituted by diamictites, shales, rhythmites, mudstones and siltstones. These rocks form isolated bodies embedded in to the crystalline basement by normal faults. Tertiary deposits, comprised of diamictites, conglomerates, sandstones and mudstones also occur in the form of isolated relicts, preserved by the presence of levels of basal conglomerates, more erosion resistant, or due to faulting which produced tilting and subsidence of the blocks. Nine sedimentary facies are defined forming associations that suggest the existence of an ancient system of allluvial fans deriving from the Japi Range, under semi-arid climate. The colluvionary deposits comprise a covering formed by unconsolidated material, and consist of basal stone lines recovered by sandy and clayish sediments with disperse quartz millimetric angular grains...(Complete abstract click electronic access below) / Mestre

No description available.

The central part of Clarkston Mountain is located in northcentral Utah in the southern part of the Malad Range. It is northwest of Clarkston, Utah. The mapped area measures 2.5 mi. in the north-south direction and 6.5 mi. in the east-west direction. It is within the Basin and Range Province. The Ute Formation of Middle Cambrian age is the oldest exposed stratigraphic unit. Other Cambrian units, in ascending order, are: Blacksmith Formation, Bloomington Formation, Nounan Formation, and St. Charles Formation. These units consist predominantly of limestone, dolostone, and shale. Units of Ordovician age include the Garden City Formation and the Swan Peak Formation. They consist of limestone and orthoquartzite, respectively. The youngest Paleozoic unit is the Fish Haven-Laketown Formation of Ordovician-Silurian age. It is dolostone. Units of Quaternary age include colluvial deposits, Lake Bonneville Group, and alluvial deposits. West-dipping, low-angle normal faults generally trend north and northwest. They were originally thrust faults formed during regional compression. A bedding-plane thrust fault separates the Bloomington and Nounan Formations. Later reversed movement on the west-dipping, low-angle thrust faults changed the stratigraphic relationships across these faults to those characteristic of normal faults. High-angle normal faults trend northwest, north, and northeast. Major normal faults extend along the western and eastern sides of Clarkston Mountain and are responsible for the present topographic relief. The structural features of the mapped area are the result of two major tectonic events. The Sevier orogeny produced eastward directed thrust faults. It began in Late Jurassic and ended in early Eocene. Basin and Range normal faulting caused reversed movement on west-dipping thrust faults, formed by the Sevier orogeny, and also produced many high-angle normal faults. It began in early Eocene and has continued into historic time in the region.

A detailed study was made of the James Peak-Sharp Mountain area, in the southern part of the Bear River Range, Utah. The mapped area is located in north-central Utah between lat. 41°22'30" N. and lat. 41°30' N. and long. 111°42'30" W. and long. 111°46' W. It measures about 3.8 miles in the east-west direction and 8.7 miles in the north-south direction. The area is centered about 22 miles south-southeast of Logan, Utah. Stratigraphic units of late Precambrian to Mississippian age underlie the mapped area. The Precambrian units include the Mutual and Browns Hole Formations. The Brigham, Langston, Ute, Blacksmith, Bloomington, Nounan, and St. Charles Formations make up a complete Cambrian section. The Ordovician Garden City and Swan Peak Formations, the Ordovician-Silurian Laketown Formation, the Devonian Water Canyon and Hyrum Formations, and the Mississippian Lodgepole and Humbug Formations overlie the St. Charles in normal succession. The oldest unit the Precambrian Mutual Formation, crops out in the southern part of the area on the eastern side of James Peak. The rock units are progressively younger toward the northern part of the area. Mesozoic rocks are not present. The Salt Lake Formation of Tertiary age directly overlies the Paleozoic rocks. The main structural feature of the area is an asymmetrical north-south-trending anticline. The eastern flank dips more steeply than the western flank. The anticline plunges gently north and dies out southward. This anticline is one of a series of asymmetrical anticlines, all steeper on the east than on the west, that includes the Strawberry Valley anticline to the east and the anticline exposed in upper Wolf Creek Canyon to the west. The late Precambrian and early Paleozoic formations, which dip northeast on the eastern flank of James Peak, make up the northeastern flank of the anticline exposed in upper Wolf Creek Canyon. The early Paleozoic to Devonian formations that form Sharp Mountain and dip gently west make up the western flank of the Strawberry Valley anticline. Low-angle thrust faults have disrupted the Precambrian and Paleozoic formations on the eastern and southeastern flanks of James Peak. Displacement on the thrust fault north of upper Wellsville Creek is about 2,000 feet. Movement was generally from the west. Normal faults have disrupted the Paleozoic and Tertiary formations along the eastern margin of Cache Valley and the Paleozoic formations east of McKenzie Mountain. Displacement is indeterminate along the eastern margin of Cache Valley. Maximum displacement, east of McKenzie Mountain, is about 1,750 feet. The normal faults truncate the folds and thrust faults. The folds and thrust faults were formed during the Laramide orogeny. The normal faults were formed during Basin and Range normal faulting. Basin and Range normal faulting is active at the present time.

Thesis (M. Phil.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2005. / Bibliography: leaves 221-229. Also available online.

In light of the recent increase of mineral exploration in the northern Cordillera, private, educational, and governmental agencies have been compelled to revisit and research areas of the Cordillera whose geologic evolution still remains enigmatic. The current study is concerned with better understanding how a region of the boundary zone separating the peri-Laurentian realm from the exotic, Insular realm evolved following deposition of the meta-sedimentary Kluane schist in the Late Cretaceous. The schist is a northwest striking 30 km wide and 160 km long belt of highly deformed greenschist to amphibolite facies meta-sedimentary rocks located east of Kluane Lake, southwestern Yukon Territory. These deformed sediments as well as numerous other deformed Jurassic-Cretaceous meta-sedimentary units present along the same boundary zone (north and south of the schist) represent important rocks that can help constrain how this part of the Cordillera has evolved since the mid-Mesozoic. To better understand how the Kluane schist evolved, detailed field mapping, petrography, and U-Pb geochronological studies were undertaken in the area encompassing the schist. This data is integrated with pre-existing and recently collected geologic databases from the region to propose a model for the tectonic and structural evolution of the Kluane schist. Conclusions drawn from this study indicate the Kluane sediments were likely deposited into a closing Late Cretaceous seaway from sources derived from Yukon-Tanana terrane (YTT) to the east. The basin into which the sediments were deposited represents a remnant ocean basin that was present between Insular terrane and YTT prior their amalgamation in the Jurassic. Thrusting of YTT over the Kluane schist basin resulted in burial, metamorphism, and ductile deformation of the schist. Contemporaneously, the early stages of the Ruby Range batholith (RRB) were intruding the schist as well as the schist/YTT contact. This batholith intruded syn- to post-tectonically from approximately ca. 77 Ma to 65 Ma and it is responsible for imparting a kilometer scale inverted contact metamophic aureole onto the Kluane schist wherein metamorphic grade decreases to the southwest. Subsequently, a gneissic sub-unit of the Kluane ‘schist’ was formed by partial melting of the RRB/Kluane schist contact. During this composite deformation event, the schist was transported to mid-crustal depths by an oblique sinistral shear zone. Shortly thereafter, the schist was exhumed and deformed by consistent northeast-over-southwest shearing. Regional scale, broad open folding of the schist ensued and likely occurred by flexural slip along foliation planes with low cohesion. Two syn- to post- tectonic igneous phases associated with Hayden Lake intrusive suite have been dated to ca. 55 Ma. This timing likely correlates with broad, open folding and a ‘late’ syn- to post-kinematic thermal overprint of the schist. The combined results of this study indicate that deformation and metamorphism of the Kluane schist was a long-lived event, extending from ca. 82 Ma to ca. 55 Ma.