The Bernic Lake Formation in the Bird River greenstone belt consists dominantly of mafic to felsic arc volcanic and volcaniclastic rocks, with varying amounts of mafic to felsic intrusive rocks, including the Bernic Lake pegmatite group. U-Pb geochronoligical analyses on selected samples around the Bernic Lake area, indicate that the Tanco gabbro, the Birse Lake granodiorite and the volcanic rocks of the Bernic Lake Formation are contemporaneous ca. 2724 Ma and form part of a singular volcanic and subvolcanic complex. The highly evolved, LCT-type, rare element-bearing Bernic Lake pegmatite group, including the world class Tanco pegmatite, was emplaced in the Bernic Lake Formation during a belt-scale tectonomagmatic event associated with G3 deformation between ca. 2650 and 2640 Ma. Early and rarely preserved isoclinal folding in the Bernic Lake Formation attributed to G1 deformation was followed north-south directed compression resulting in refolding and transposition of G1 structures by east-west trending upright F2 folds. Continued compression caused strain localization and south-side-up shearing along the North Bernic Lake Shear Zone (NBLSZ), which juxtaposes MORB-like basalt of the south panel to the south against arc rocks of the Bernic Lake Formation to the north. G3 deformation is characterized by a spaced S3 fracture cleavage that overprints the penetrative S2 fabric, and dextral reactivation of the NBLSZ. Pegmatitic melt ascended from depth along the reactivated NBLSZ during this time and was emplaced both within the shear zone and within rock units adjacent to it. The shapes and orientations of the pegmatites are controlled in part by the rheology of the host rocks into which they were emplaced. Rheologically competent lithologies responded to G3 strain by brittle fracture and the pegmatites occurring therein are flat and tabular; rheologically incompetent lithologies responded to G3 strain by ductile-brittle deformation and the pegmatites therein are irregular, folded, and/or boudinaged. The contrasting styles suggest that the pegmatites intruded while the rocks of the Bernic Lake Formation were at or near the brittle-ductile transition.

A erupção histórica de 1580 A.D. ocorreu ao sudoeste da Ilha de São Jorge, Açores recobrindo uma área total de 4 km². Este trabalho teve como objetivo caracterizar as diferentes morfologias de lava de 1580 A.D, juntamente com a definição de padrões petrográficos e geoquímicos. A erupção gerou quatro flow fields: Ribeira do Almeida, Queimada, Ribeira do Nabo I e Ribeira do Nabo II. A descrição detalhada das lavas permitiu identificar spiny, sheet, e slabby pahoehoe e derrames do tipo ‘a´ā. Próximo aos cones, derrames do tipo ‘a´ā são descritos. Com a constante erupção, estas lavas fluem em direção a costa formando deltas de lava ao entrar em contato com a água. Estes deltas geram um relevo sub-horizontal favorecendo a colocação de derrames do tipo sheet pahoehoe. A contínua alimentação interna favorece o espessamento dos derrames, podendo gerar o rompimento da superfície formando derrames slabby pahoehoe. Os estágios finais da erupção são marcados por derrames do tipo ‘a´ā canalizados lateralmente e sobre os derrames do tipo sheet pahoehoe. A variação na superfície dos derrames é controlada pelas taxas de efusão e pela topografia. Petrograficamente, todas as lavas da erupção de 1580 A.D. são olivina basaltos. Os dados geoquímicos indicam uma afinidade magmática alcalina com os termos menos diferenciados localizados na região de Ponta Queimada. Isto pode ser explicado por uma constante recarga de magma mais primitivo na câmara magmática. Os padrões de ETR normalizados sugerem que os basaltos estudados foram gerados a partir de um baixo grau de fusão de uma fonte profunda e enriquecida do tipo OIB. O estudo dos aspectos físicos dos derrames de 1580 juntamente com a petrografia e geoquímica permitiram compreender a história geológica deste evento. / The historic eruption of 1580 A.D. occurred in the southwestern of São Jorge Island, in the central Azores covering a total area of 4 km². This work provides a characterization of the distribution and morphology of the 1580 A.D. lava flows, integrated to petrography and geochemistry. The eruption formed four distinct flows fields: Ribeira do Almeida, Queimada, Ribeira do Nabo I and Ribeira do Nabo II. Detailed geological analysis allowed the identification of spiny, sheet and sllaby pahoehoe and ‘a´ā lava morphotypes. Near the vent, the flow fields are characterized by channelized ‘a´ā flows. With continuous eruption, these lavas flowed downwards forming fan-shaped lava deltas when entering the sea. Sheet pahoehoe flows overlay the ‘a´ā lavas and with continuous inflation the surface of the flows breaks generating slabby pahoehoe surface. The gradual increase in surface fragmentation form rubbly surfaces. In the late stages of the eruption channelized ‘a´ā flows were emplaced, depositing laterally and over the sheet pahoehoe flows. The variations in the lava surface are controlled by the effusion rates and the topography. Petrographically, all lava flows are olivine basalts. The chemistry of the basalts indicate an alkaline nature for the 1580 volcanism. The less-evolved compositions are found in Ribeira do Almeida and this fact can be related to continuous recharge of the magma chamber with more primitive melts. Normalized REE profiles show that the basalts were generated by low volumes of melt of an enriched OIB source. The study of the physical aspects of 1580 lava flows with petrography and geochemistry allowed understand the geologic history of this event.

A erupção histórica de 1580 A.D. ocorreu ao sudoeste da Ilha de São Jorge, Açores recobrindo uma área total de 4 km². Este trabalho teve como objetivo caracterizar as diferentes morfologias de lava de 1580 A.D, juntamente com a definição de padrões petrográficos e geoquímicos. A erupção gerou quatro flow fields: Ribeira do Almeida, Queimada, Ribeira do Nabo I e Ribeira do Nabo II. A descrição detalhada das lavas permitiu identificar spiny, sheet, e slabby pahoehoe e derrames do tipo ‘a´ā. Próximo aos cones, derrames do tipo ‘a´ā são descritos. Com a constante erupção, estas lavas fluem em direção a costa formando deltas de lava ao entrar em contato com a água. Estes deltas geram um relevo sub-horizontal favorecendo a colocação de derrames do tipo sheet pahoehoe. A contínua alimentação interna favorece o espessamento dos derrames, podendo gerar o rompimento da superfície formando derrames slabby pahoehoe. Os estágios finais da erupção são marcados por derrames do tipo ‘a´ā canalizados lateralmente e sobre os derrames do tipo sheet pahoehoe. A variação na superfície dos derrames é controlada pelas taxas de efusão e pela topografia. Petrograficamente, todas as lavas da erupção de 1580 A.D. são olivina basaltos. Os dados geoquímicos indicam uma afinidade magmática alcalina com os termos menos diferenciados localizados na região de Ponta Queimada. Isto pode ser explicado por uma constante recarga de magma mais primitivo na câmara magmática. Os padrões de ETR normalizados sugerem que os basaltos estudados foram gerados a partir de um baixo grau de fusão de uma fonte profunda e enriquecida do tipo OIB. O estudo dos aspectos físicos dos derrames de 1580 juntamente com a petrografia e geoquímica permitiram compreender a história geológica deste evento. / The historic eruption of 1580 A.D. occurred in the southwestern of São Jorge Island, in the central Azores covering a total area of 4 km². This work provides a characterization of the distribution and morphology of the 1580 A.D. lava flows, integrated to petrography and geochemistry. The eruption formed four distinct flows fields: Ribeira do Almeida, Queimada, Ribeira do Nabo I and Ribeira do Nabo II. Detailed geological analysis allowed the identification of spiny, sheet and sllaby pahoehoe and ‘a´ā lava morphotypes. Near the vent, the flow fields are characterized by channelized ‘a´ā flows. With continuous eruption, these lavas flowed downwards forming fan-shaped lava deltas when entering the sea. Sheet pahoehoe flows overlay the ‘a´ā lavas and with continuous inflation the surface of the flows breaks generating slabby pahoehoe surface. The gradual increase in surface fragmentation form rubbly surfaces. In the late stages of the eruption channelized ‘a´ā flows were emplaced, depositing laterally and over the sheet pahoehoe flows. The variations in the lava surface are controlled by the effusion rates and the topography. Petrographically, all lava flows are olivine basalts. The chemistry of the basalts indicate an alkaline nature for the 1580 volcanism. The less-evolved compositions are found in Ribeira do Almeida and this fact can be related to continuous recharge of the magma chamber with more primitive melts. Normalized REE profiles show that the basalts were generated by low volumes of melt of an enriched OIB source. The study of the physical aspects of 1580 lava flows with petrography and geochemistry allowed understand the geologic history of this event.

The Weinsberg Composite Pluton, located in the southern part of the Moldanubian Batholith is a large intrusive body with complex internal fabrics, petrogenesis and emplacement processes. On the basis of geochemistry and zircon morphology classification the dominating lithology in the northeastern part of the pluton seems to be the second type of the Weinsberg granitoids (WbG II). Based on the integration of the structural, petrological and geochemical data set acquired from the investigated area, the interpretation of geodynamic evolution and emplacement of the eastern part of the Weinsberg Pluton could be proposed. This interpretation invokes: (a) indentation and underthrusting of a continental microplate (Brunia) in the east at around ~340-330 Ma, driving mantle delamination and subsequent heating and anatexis in the metapelitic lower crust as the heterogeneous source for Weinsberg- and Eisgarn-types of granitoids; (b) subsequent growth of a large metamorphic dome along the edge of the Brunia indentor followed by polyphase emplacement of entire eastern part of the Moldanubian Batholith around ~330-325 Ma including the Weinsberg Composite Pluton in the south; (c) increasing role of the N-S shortening and associated NW-SE dextral shearing along localized shear zones which caused the prevailing...

The spatial categorisations of urban and rural are still used in academia, lay terminology and policy formation in spite of a postmodern obsession with the deconstruction of binaries. Hitherto, the urban rural dichotomy has been exposed to little scrutiny, and the critiques that have been made come from the epistemological standpoint of total urbanisation which assumes the rural will be effaced by a perennial urban sprawl. The rural urban dichotomy is a derivative of the larger ideological dualism of nature and society and it has long been postulated, particularly from the standpoint of political ecology, that in the Anthropocene, nature does not exist beyond human influence. This would, in theory, support the theory that rural space is becoming effaced. Previous studies have, however, demonstrated that this subjugation of the rural to the urban works to stigmatise rural populations and engender disenfranchisement that has led to a resurgence in far-right nationalism across much of Europe. This subjugation has been enforced through  this very urban norm in which both technocrats and academics favour the urban as a field for policy formation and research. When attempting to define the urban and the rural, it was found that the terms (a) are confused and confusing, evading any useful definition; (b) perpetuate a false neutrality that assumes a linear progression from rural to urban and (c) fail to recognise the complexities of space which resists binary distinctions. As such, I used Lefebvre’s spatial trifecta which suggests space is produced by three complimentary and contradictory processes: of perceived space (the material space of what we can actually see and touch, altered by seemingly banal everyday practices), conceived space (the (re)representations of space that are circulated by planners and technocrats) and lived space (the affectual space of emotion, memory and meanings) in order to think through the problems of the binary.  As such, this thesis aimed to explore whether the urban and the rural still function as legitimate spatial categories and, in doing so, used an emplaced, embodied and mobile exploration of five case studies within Stockholms län in order to explore the phenomena. This was appropriate as it mirrored the affectual potential believed to be induced through rural and natural landscapes. Indeed, by developing a methodology that can better account for lived space, we can attempt to dislodge perceived and conceived spaces as the more easily accessible conceptual framework for thinking through space. The findings showed that there were many different species of urban and rural spaces, many spaces that were both urban and rural and many that were neither. Indeed, an acquiescence of purportedly rural and urban features within purportedly urban spaces, and vice versa, was the most telling result in terms of disrupting the idea that the urban and rural are stable but antipodal spatial categories. I also found the rural to be a coterminous process that produces space with and against urban landscapes, and thus should not be subjugated.

Several off-shore volcano-plutonic complexes are imaged in detail in the Parihaka 3D seismic survey in the Taranaki Basin of New Zealand. Three intrusions were analyzed for this study. Part of the Mohakatino Volcanic Centre (15 to 1.6 Ma), these intrusions have steep sides, no resolvable base reflectors, no internal stratification or structure, and they exhibit doming and faulting in the sedimentary strata above the intrusions. Deformation along the sides is dominated by highly attenuated, dipping strata with dips of 45° or higher that decrease rapidly away from the intrusions. Doming extends several hundred meters from the margins and produced many high-angle normal faults and thinned strata. The intrusions lie near normal faults with the Northern Intrusion lying directly adjacent to a segment of the Parihaka Fault. The Central Intrusion has localized normal faults cutting a graben in the area directly above the intrusion and extending in a NE-SW direction away from it. The Western Intrusion is near the western edge of the Parihaka 3D dataset and is not situated directly adjacent to extensional faults.Two distinct zones of intrusion-related faults developed around both the Northern and Central Intrusions representing two different stress regimes present during emplacement, a local stress field created by the intrusions during emplacement and the regional stress field. The deeper zones contain short radial faults that extend away from the intrusion in all directions, representing a local stress field. The shallower faults have a radial pattern above the apex of each intrusion, but farther from it, they follow the regional stress field and trend NE. Using our techniques to interpret radial faulting above both intrusions and the principal of cross-cutting relations, timing of emplacement for these intrusions are 3.5 Ma for the Northern Intrusion and between 5 and 4 Ma for the Central and Western Intrusions.Observed space-making mechanisms for the Northern and Central Intrusions include doming (~16% and 11%, respectively), thinning and extension of roof strata (~4% for both), and extension within the basin itself (29% and 12%). Stoping and floor subsidence may have occurred, but are not visible in the seismic images. Magmatic extension may have played a significant role in emplacement.Several gas-rich zones are also imaged within the seismic data near the sea-floor. They appear as areas of acoustic impedance reversal compared to surrounding sedimentary strata and have a reversal of amplitude when compared to the sea floor. The gas in these zones is either biogenic or sourced from deeper reservoirs cut by normal faults.

Detailed 3D seismic images of a volcano-plutonic complex offshore northwestern New Zealand indicate the intrusive complex lies in a relay zone between NE-trending en echelon normal faults. A series of high angle normal faults fan out from the margin of the Southern Intrusive Complex and cut the folded strata along the margin. These faults terminate against the margins of the intrusion, extend as much as 1 pluton diameter away from the margin, and then merge with regional faults that are part of the Northern Taranaki Graben. Offset along these faults is on the order of 10s to over 100 meters. Strata on top of the complex are thinned and deformed into a faulted dome with an amplitude of about 0.7 km. Steep dip-slip faults form a semi-radial pattern in the roof rocks, but are strongly controlled by the regional stress field as many of the faults are sub-parallel to those that form the Northern Taranaki Graben. The longest roof faults are about the same length as the diameter of the pluton and cut through approximately 0.7 km of overlying strata. Fault offset gradually diminishes vertically away from the top of the intrusion. The Southern Intrusive Complex is a composite intrusion and formed from multiple steep-sided intrusions as evidenced by the complex margins and multiple apophyses. Small sills are apparent along the margins and near the roof of the Southern complex. Multiple episodes of deformation are also indicated by a series of unconformities in the sedimentary strata around the complex. Two large igneous bodies make up the composite intrusion as evidenced by the GeoAnomaly body detection tool. The Southern Intrusive Complex has a resolvable volume of 277 km3. Room for the complex was made by multiple space-making mechanisms. Roof uplift created ~3% of the space needed. Compaction/porosity loss is estimated to have contributed 20-40% of the space needed. Assimilation may have created ~0-30% space. Extension played a major role in creating the space needed and is estimated to have created a minimum of 33% of the space. Floor subsidence and stoping may have occurred, but are not resolvable in the seismic survey.

The central White-Inyo Range in eastern California is a deformed section of Neoproterozoic through Cambrian sedimentary rocks which has been intruded by granitic plutons associated with the Mesozoic Sierra Nevada intrusive suites to the west. My dissertation involves a characterization of the pre-plutonic regional deformation within the central White-Inyo Range and an understanding of the deformation of the wall rocks and magmas associated with pluton emplacement. The four chapters in this dissertation are a compilation of three published articles (two in journals, one in a field guide-book) and one manuscript. The regional deformation was characterized by measuring the orientation of folds, bedding, and cleavage throughout the range, as well as utilizing these data from other authors and from published geologic maps. Synthesis of the data indicate that all regional structures pre-date the intrusions. The transition from regional structures to aureole structures reveals components of horizontal and vertical translation and rotation of bedding associated with forceful emplacement. The Jurassic Eureka Valley-Joshua Flat-Beer Creek (EJB) composite pluton and Cretaceous Papoose Flat pluton, as well as the deformed metasedimentary rocks surrounding these plutons, have been examined in detail. Penetrative shortening of the wall rocks was studied in detail along three traverses across the aureole of the EJB pluton and from specific outcrops throughout the aureole. Sedimentary formations have been attenuated to approximately one third of their regional stratigraphic thicknesses. Strain is characterized by flattening and plane strain. Deformation mechanisms vary, but are dominated by intracrystalline slip and climb and by grain boundary sliding. Contact metamorphism is characterized by andalusite followed by sillimanite. The internal fabric of the EJB pluton has been analyzed through the study of the anisotropy of magnetic susceptibility (AMS). Samples were collected at 210 locations ( 420 drill cores, approximately 1000 samples) throughout the pluton. Maps of the fabric and magnetic parameters reveal that magnetic fabrics cross-cut some compositional boundaries and parallel others. Comparison between the magnetic fabrics and the aureole structures indicate that the magma and surrounding plastic aureole deformed as a single unit during emplacement. Detailed porphyroblast-matrix analysis within the concordant metasedimentary aureole rocks surrounding the Papoose Flat pluton indicates that inclusion trails within porphyroblasts can be used as strain markers to restore the aureole rocks to their prepluton emplacement position. The kinematics of rotation, the change in thickness and volume, and the amount of translation of the metasedimentary formations within the aureole have been determined using porphyroblast-matrix relationships, in combination with measurement of stratigraphic sections and whole-rock geochemical analyses. The emplacement of the EJB and Papoose Flat plutons is modeled as occurring in two stages. The first stage is sill-like, producing a thermal aureole which lowers the viscosity of the surrounding sedimentary rocks. The second stage is forceful, causing upward and outward translation and rotation of the surrounding aureole. Porphyroblastmatrix relationships from the EJB and Papoose Flat pluton, and from the literature on the Ardara pluton, Ireland, and the Cannibal Creek pluton, Australia, support this two stage emplacement model for concordant plutons. / Ph. D.

This study documents the deformation history of the Santa Rita Flat pluton, eastern California, from the time of emplacement to post-emplacement transpressional shearing, and consists of manuscripts that make up three chapters. The first chapter addresses the emplacement of the Santa Rita Flat pluton using anisotropy of magnetic susceptibility (AMS). The second chapter describes the kinematic analysis of cross-cutting shear zones within the western margin of the pluton. The third chapter is an informal paper on the U/Pb dating of two sheared felsic dikes from the pluton. AMS of the Santa Rita Flat pluton indicates that the paramagnetic and ferromagnetic minerals define a foliation which is arched into an antiformal structure in the central to southern parts of the pluton. The northern part of the pluton displays an east-west striking magnetic foliation which lacks a fold-like geometry. Previously published field mapping and petrologic surveys of the pluton and surrounding wall rocks indicate that the southern margin and northern part of the Santa Rita Flat pluton represents the roof and core of the pluton, respectively. Integration of our analysis of the internal structure of the pluton with previously published work on the regional structure of the surrounding metasedimentary wall rocks, suggests that the pluton may have initially been intruded as a sill-like or "saddle reef" structure along a stratigraphically controlled mechanical discontinuity in the hinge zone of an enveloping regional-scale synform. Subsequent vertical inflation of this sill resulted in local upward doming of the overlying pluton roof and formation of the antiformal structure now observed at the current erosion level in the central-southern part of the pluton and overlying locally preserved roof rocks. No corresponding fold structure is indicated by AMS analysis in the northern part of the pluton, which is exposed at a deeper level, and represents a section closer to the pluton core. Emplacement of the Santa Rita Flat pluton at 164 Ma overlaps in time with regional deformation at ~185 - ~148 Ma (Middle - Late Jurassic) recognized in the southern Inyo Mountains. Northwest trending folds are pervasive along the western flank of the Inyo and White Mountains, and may have accommodated strains at the lateral tips of thrust faults which crop out in the southern Inyo Mountains. We speculate that space for initial emplacement of the Santa Rita Flat pluton may have been produced by layer-parallel slip and hinge-zone dilation, accompanied by axis-parallel slip during formation of a regional scale thrust-related synform. The Santa Rita shear system (SRSS) is composed of a series of discrete NW-SE striking steeply dipping shear zones that cut and plastically deform granitic rocks of the Santa Rita Flat pluton. The shear zones exhibit a domainal distribution of gently and steeply plunging stretching lineations, and are located at planar mechanical discontinuities between the granite and a series of felsic/mafic dikes which intrude the pluton. Mylonitized dikes within the shear zones contain syntectonic mineral assemblages not observed in dikes outside the shear zones, indicating that the dikes were intruded prior to shear zone development. Correlation with geometrically similar shear zones in the Sierra Nevada batholith to the west, suggests that the SRSS probably nucleated from a regional stress field in Cretaceous times (~90-78 Ma). Strain is heterogeneous within the shear zones, with local development of protomylonite, mylonite, ultramylonite and phyllonite. Strain heterogeneity within the granite is attributed to fluid infiltration and chemical reaction and alteration of feldspar to fine-grained mica. These deformation-induced mineral changes would have resulted in progressive mechanical weakening over time of rocks within the SRSS. The phyllonites occur predominantly within steeply lineated shear zones and contain mylonitized foliation-parallel quartz veins. The pattern of c-axis preferred orientation in these quartz veins indicates that deformation within the shear zones occurred under plane strain conditions. Locally, quartz veins also cut the foliation planes, reflecting high pore fluid pressures during evolution of the SRSS. These cross-cutting quartz veins are also plastically deformed, and their c-axis patterns indicate weak constrictional strains. The orientation of the shear zones, together with their strain paths, are used to develop a transpressional kinematic model for development of the SRSS within a progressively rotating stress field. / Master of Science

The Saxonian Granulite Massif in the Saxothuringian Domain of the Bohemian Massif, is represented by a single granulite body consisting of felsic and mafic granulites formed during Variscan tectono-metamorphic event. The granulites with peak metamorphic P-T conditions of ~2.3 GPa and 970-1060 řC (Fuhrman and Lindsley, 1988; Rötzler and Romer, 2001) were exhumed and emplaced into the palaeozic sedimentary cover sequence, which resulted into contact metamorphism affecting these metasedimentary rocks and development of a contact metamorphic aureole. In the map view, the granulite body has elongated shape with the long axis oriented in NE- SW direction and it is surrounded by the so called schist mantle reflecting the extent of the contact metamorphic aureole. Within two kilometers distance away from the contact with granulite body, the metamorphic grade in metasediments decreases from cordierite gneiss, andalusite bearing micaschist to phyllite. Detailed field structural analysis in the studied area revealed a deformation record associated with four main deformation phases. In granulites the oldest deformation fabric contains kyanite and sillimanite. This fabric is locally overprinted by the subhorizontal green schist facies fabric, mainly along the margins of the granulite body. In metasediments, the...