This thesis is missing either page 57 or 58. The other copies of this thesis do not have this page either. -Digitization Centre / This study is an investigation of two regions which were once part of the same Proterozoic margin: the Frontenac Axis in the Southeastern Grenville Province of Ontario, and the island of Islay in Scotland. Shieh (1985) performed an oxygen isotopic study on the granitic plutons and surrounding metasediments in the Frontenac terrane. For the granites south of the Rideau Lake Fault, he observed extremely high 18O/16O ratios of +14.0%o (relative to SHOW), whereas north of the fault, the plutons gave ratios of around 10%o. Five of the plutons in Shieh's study have been dated using U-Pb zircon geochronology, with the following results: Battersea -1165 ± 3 Ma, Lyndhurst -1166 ± 3 Ma, Perth Road -1166 ± 3 Ma, Crow Lake -1176 ± 2 Ma, and Westport -1076 ± 2 Ma. The zircon ages are younger than the depleted mantle Nd model ages obtained (1211 to 1480 Ma) and signify that the plutons may be derived from a mantle source with contamination by the older surrounding metasediments which have an average Nd model age of 1790 Ma. Correlation between initial Nd (ENd(t) from +1 to +3) and initial Sr (Esr(t) from +9 to +21) also shows a mixed origin for the plutons. However, oxygen isotopes show that contamination by marble may also have occurred. Two features distinguish the Frontenac terrane southeast of the Rideau Lake Fault (RLF) from the Central Metasedimentary Belt (CMB) to the northwest: 1) the anorogenic (i.e. within plate) chemical signatures of the plutons, which are similar to the Hid-Proterozoic anorogenic granites that occur throughout North America (Anderson, 1983); and 2) the unique zircon ages for the plutons south of the RLF (1166 to 1176 Ha) that occur nowhere else in the CMB. This implies that the two areas define different crustal terranes. However, since Penokean (ca. 1800 Ha) crustal extraction ages are found in both terranes they may represent displaced segments of a single Penokean continental margin. In Scotland, a gneiss terrane on Islay was always inferred to be part of the Archean Lewisian complex. However, isotopic evidence shows that the Islay terrane is early Proterozoic in age (1782 Ha by U-Pb zircon geochronology) and that it is juvenile mantle-derived material, not a reworking of Archean crust during the Proterozoic. As a result, two major implications for the crustal evolution of Northern Britain are: 1) the Grampian terrane, an area directly adjacent to the newly defined Proterozoic Islay block, is probably underlain by Proterozoic basement; and 2) Northern Britain can be included in the Lower Proterozoic reconstruction of the Laurentian Shield. The similar crustal extraction ages observed in the Grenville of Ontario and on Islay give proof that these areas were part of a major 1.8 to 1.9 Ga crustal formation event, stretching from the southwestern U.S. to Finland. / Thesis / Master of Science (MS)

Orientador: Antonio Misson Godoy / Banca: Antenor Zanardo / Banca: Marco Aurélio Farias de Oliveira / Banca: Romulo Machado / Banca: Ticiano José Saraiva dos Santos / Resumo: O Maciço do Rio Apa ocorre no sudoeste do estado de Mato Grosso do Sul e corresponde à porção meridional do Cráton Amazônico de idade dominantemente Paleoproterozóica. O Complexo Rio Apa, mais antigo, é constituído por ortognaisses migmatíticos, além de anfibolitos, tonalitos e granodioritos. O Grupo Alto Tererê é composto por xistos, biotita - muscovita gnaisses e quartzitos micáceos, comumente granatíferos, além de rochas metabásicas, em fácies anfibolito baixa. O Grupo Amonguijá é definido pela Suíte Intrusiva Alumiador que representa um batólito de composição sieno- a monzogranítica e pela Suíte Vulcânica Serra da Bocaina composta por rochas vulcanoclásticas de composição álcali - riólito a monzoriólitos e produtos piroclásticos. Sobreposta, a leste e a sul ocorrem as rochas metassedimentares Neoproterozóicas da Faixa de Dobramento Paraguai (grupos Cuiabá, Corumbá e Jacadigo-Formação Urucum). O quadro estrutural - metamórfico é identificado por 5 fases deformacionais, mas sua atual estruturação tectônica-metamórfica passa pelo arranjo tectônico superimposto da Faixa de Dobramentos Paraguai. As rochas do Complexo Rio Apa, Grupo Alto Tererê e Grupo Amonguijá registram uma evolução estrutural reliquiar antiga definida pelas fases (Dn-1 e Dn). As fases deformacionais (Dn+1 e Dn+2) encontram-se visíveis principalmente nas rochas da Faixa de Dobramento Paraguai, enquanto deformações (Dn+3) superimpõem a todas as sequências / Abstract: Geological and structural frame of the Rio Apa Massif, southeastern of the Amazonian Craton (MS), Brasil Rio Apa Massif crops out in the Mato Grosso do Sul state and corresponds to the southeastern portion of the Amazonian Craton dominantly Paleoproterozoic in age. Rio Apa Complex is oldest and it is composed mainly by migmatitic orthogneisses, beyond amphybolites, tonalities and granodiorite. Alto Tererê Group is composed by schists, biotite-muscovite gneisses and micaceous quartzites generally rich in garnets, beyond metabasic rocks of low amphibolite facies. The Amonguijá Group is constituted by Alumiador Intrusive Suite, which is represented by a sieno to monzogranitic batholith and Serra da Bocaina Volcanic Suite composed of volcanoclastic rocks of alkali riolites to monzoriolites compositions and pyroclastic products. Overlaying towards East and South occurs Neoproterozoic metasedimentary rocks from the Paraguai Folded Belt (Cuiabá, Corumbá and Jacadigo Groups-Urucum Formation). Structural-metamorphic framewok is identified by five deformational phases but the actual tectonic and metamorphic structure shows the superposed tectonic array of the Paraguai Folded Belt. Rocks from Rio Apa Complex, Alto Tererê Group and Amonguijá Group record an older structural evolution defined by (Dn-1 and Dn). The deformational phases (Dn+1 and Dn+2) are visible mainly in rocks of Paraguai Folded Belt beyond the last deformation (Dn+3) that imprints all sequences / Doutor

The Atnarko complex located in west-central British Columbia comprises pre-Early Jurassic metavolcanic and metasedimentary rocks, termed the Atnarko assemblage, which is structurally interleaved with Late Triassic to Early Cretaceous orthogneiss. The Atnarko assemblage correlates with continental margin assemblages found within the Coast plutonic complex. Tectonic interaction between the Insular and Intermontane superterranes resulted in several phases of deformation including; 1) poorly preserved Jurassic deformation, 2) Early to mid-Cretaceous, southwest to west directed, compression, 3) mid-Cretaceous, north to northeast directed, compression, 4) mid- to Late Cretaceous dextral and sinistral ductile/brittle shearing, and 5) post latest Cretaceous brittle faulting. Peak metamorphism coincides with generation of migmatite in the Early Cretaceous (~117-115 Ma) and is contemporaneous with penetrative ductile fabrics. The Atnarko complex had cooled below 350°C by the Late. Comparison of the Atnarko complex to equivalent portions of the orogen along strike, indicates a post mid-Cretaceous change in structural style. To the northwest the orogen records continued southwest-directed compression which dominates the deformation style; while to the southeast large dextral strike-slip faults dominate. Relative plate motions between ca. 70-60 Ma indicate that dextral transpression occurred between the Kula and North American plates. Strain during this transpressive deformation was partitioned into compressive and translational regions. The Atnarko complex area is situated at the transition between translation and compression. The conditions of the lower and middle crust within the orogen were established by how strain was partitioned across the orogen. The distributed strain also shaped how the orogen responded to Tertiary extension. Continued compression to the northwest of the Atnarko complex led to increased crustal thickness and partial melting of lower and middle crust in the Tertiary. Conversely, the cessation of compression in the southeast lead to a more stable (i.e. cooler) crustal lithosphere. A change in relative plate motions in the early Tertiary triggered full-scale, orogen-perpendicular, collapse in the northwest facilitated by decoupling between the middle and lower crusts along thermally weakened layers. Localized orogen-parallel extension occurred in the southeast which was kinematically linked to large dextral strike-slip faults where the upper crust remained coupled to the middle and lower crust.

The Atnarko complex located in west-central British Columbia comprises pre-Early Jurassic metavolcanic and metasedimentary rocks, termed the Atnarko assemblage, which is structurally interleaved with Late Triassic to Early Cretaceous orthogneiss. The Atnarko assemblage correlates with continental margin assemblages found within the Coast plutonic complex. Tectonic interaction between the Insular and Intermontane superterranes resulted in several phases of deformation including; 1) poorly preserved Jurassic deformation, 2) Early to mid-Cretaceous, southwest to west directed, compression, 3) mid-Cretaceous, north to northeast directed, compression, 4) mid- to Late Cretaceous dextral and sinistral ductile/brittle shearing, and 5) post latest Cretaceous brittle faulting. Peak metamorphism coincides with generation of migmatite in the Early Cretaceous (~117-115 Ma) and is contemporaneous with penetrative ductile fabrics. The Atnarko complex had cooled below 350°C by the Late. Comparison of the Atnarko complex to equivalent portions of the orogen along strike, indicates a post mid-Cretaceous change in structural style. To the northwest the orogen records continued southwest-directed compression which dominates the deformation style; while to the southeast large dextral strike-slip faults dominate. Relative plate motions between ca. 70-60 Ma indicate that dextral transpression occurred between the Kula and North American plates. Strain during this transpressive deformation was partitioned into compressive and translational regions. The Atnarko complex area is situated at the transition between translation and compression. The conditions of the lower and middle crust within the orogen were established by how strain was partitioned across the orogen. The distributed strain also shaped how the orogen responded to Tertiary extension. Continued compression to the northwest of the Atnarko complex led to increased crustal thickness and partial melting of lower and middle crust in the Tertiary. Conversely, the cessation of compression in the southeast lead to a more stable (i.e. cooler) crustal lithosphere. A change in relative plate motions in the early Tertiary triggered full-scale, orogen-perpendicular, collapse in the northwest facilitated by decoupling between the middle and lower crusts along thermally weakened layers. Localized orogen-parallel extension occurred in the southeast which was kinematically linked to large dextral strike-slip faults where the upper crust remained coupled to the middle and lower crust.

Made available in DSpace on 2014-06-11T19:32:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-09-09Bitstream added on 2014-06-13T19:42:58Z : No. of bitstreams: 1 manzano_jc_dr_rcla.pdf: 3069122 bytes, checksum: cf569dcb57546619aa77beff7754c326 (MD5) / O Maciço do Rio Apa ocorre no sudoeste do estado de Mato Grosso do Sul e corresponde à porção meridional do Cráton Amazônico de idade dominantemente Paleoproterozóica. O Complexo Rio Apa, mais antigo, é constituído por ortognaisses migmatíticos, além de anfibolitos, tonalitos e granodioritos. O Grupo Alto Tererê é composto por xistos, biotita - muscovita gnaisses e quartzitos micáceos, comumente granatíferos, além de rochas metabásicas, em fácies anfibolito baixa. O Grupo Amonguijá é definido pela Suíte Intrusiva Alumiador que representa um batólito de composição sieno- a monzogranítica e pela Suíte Vulcânica Serra da Bocaina composta por rochas vulcanoclásticas de composição álcali - riólito a monzoriólitos e produtos piroclásticos. Sobreposta, a leste e a sul ocorrem as rochas metassedimentares Neoproterozóicas da Faixa de Dobramento Paraguai (grupos Cuiabá, Corumbá e Jacadigo–Formação Urucum). O quadro estrutural - metamórfico é identificado por 5 fases deformacionais, mas sua atual estruturação tectônica-metamórfica passa pelo arranjo tectônico superimposto da Faixa de Dobramentos Paraguai. As rochas do Complexo Rio Apa, Grupo Alto Tererê e Grupo Amonguijá registram uma evolução estrutural reliquiar antiga definida pelas fases (Dn-1 e Dn). As fases deformacionais (Dn+1 e Dn+2) encontram-se visíveis principalmente nas rochas da Faixa de Dobramento Paraguai, enquanto deformações (Dn+3) superimpõem a todas as sequências / Geological and structural frame of the Rio Apa Massif, southeastern of the Amazonian Craton (MS), Brasil Rio Apa Massif crops out in the Mato Grosso do Sul state and corresponds to the southeastern portion of the Amazonian Craton dominantly Paleoproterozoic in age. Rio Apa Complex is oldest and it is composed mainly by migmatitic orthogneisses, beyond amphybolites, tonalities and granodiorite. Alto Tererê Group is composed by schists, biotite-muscovite gneisses and micaceous quartzites generally rich in garnets, beyond metabasic rocks of low amphibolite facies. The Amonguijá Group is constituted by Alumiador Intrusive Suite, which is represented by a sieno to monzogranitic batholith and Serra da Bocaina Volcanic Suite composed of volcanoclastic rocks of alkali riolites to monzoriolites compositions and pyroclastic products. Overlaying towards East and South occurs Neoproterozoic metasedimentary rocks from the Paraguai Folded Belt (Cuiabá, Corumbá and Jacadigo Groups-Urucum Formation). Structural-metamorphic framewok is identified by five deformational phases but the actual tectonic and metamorphic structure shows the superposed tectonic array of the Paraguai Folded Belt. Rocks from Rio Apa Complex, Alto Tererê Group and Amonguijá Group record an older structural evolution defined by (Dn-1 and Dn). The deformational phases (Dn+1 and Dn+2) are visible mainly in rocks of Paraguai Folded Belt beyond the last deformation (Dn+3) that imprints all sequences

The Atnarko complex located in west-central British Columbia comprises pre-Early Jurassic metavolcanic and metasedimentary rocks, termed the Atnarko assemblage, which is structurally interleaved with Late Triassic to Early Cretaceous orthogneiss. The Atnarko assemblage correlates with continental margin assemblages found within the Coast plutonic complex. Tectonic interaction between the Insular and Intermontane superterranes resulted in several phases of deformation including; 1) poorly preserved Jurassic deformation, 2) Early to mid-Cretaceous, southwest to west directed, compression, 3) mid-Cretaceous, north to northeast directed, compression, 4) mid- to Late Cretaceous dextral and sinistral ductile/brittle shearing, and 5) post latest Cretaceous brittle faulting. Peak metamorphism coincides with generation of migmatite in the Early Cretaceous (~117-115 Ma) and is contemporaneous with penetrative ductile fabrics. The Atnarko complex had cooled below 350°C by the Late. Comparison of the Atnarko complex to equivalent portions of the orogen along strike, indicates a post mid-Cretaceous change in structural style. To the northwest the orogen records continued southwest-directed compression which dominates the deformation style; while to the southeast large dextral strike-slip faults dominate. Relative plate motions between ca. 70-60 Ma indicate that dextral transpression occurred between the Kula and North American plates. Strain during this transpressive deformation was partitioned into compressive and translational regions. The Atnarko complex area is situated at the transition between translation and compression. The conditions of the lower and middle crust within the orogen were established by how strain was partitioned across the orogen. The distributed strain also shaped how the orogen responded to Tertiary extension. Continued compression to the northwest of the Atnarko complex led to increased crustal thickness and partial melting of lower and middle crust in the Tertiary. Conversely, the cessation of compression in the southeast lead to a more stable (i.e. cooler) crustal lithosphere. A change in relative plate motions in the early Tertiary triggered full-scale, orogen-perpendicular, collapse in the northwest facilitated by decoupling between the middle and lower crusts along thermally weakened layers. Localized orogen-parallel extension occurred in the southeast which was kinematically linked to large dextral strike-slip faults where the upper crust remained coupled to the middle and lower crust. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

- 1 - English abstract The late-Variscan magnesium-rich potassic to ultrapotassic igneous rocks create numerous dykes, dyke swarms and several plutonic bodies at the boundary between the Moldanubian Zone and the Teplá-Barrandian Block of the Bohemian Massif. They represent a volumetrically smaller group of igneous rock but they are the key to understand generation of melt and processes of mantle metasomatism and shallow-level magma differentiation. In addition, they are considered as an indicator of the tectonic evolution of this part of the Bohemian Massif during the final stages of the Variscan orogenesis. Currently, they are the subject of discussion by several authors in terms of their genesis, emplacement time and geodynamic significance. The presented thesis is a compilation of four scientific publications that are aimed at the petrological study of selected (ultra)-potassic dyke rocks from several localities at the western border of the Moldanubian Zone. The study of mineral textures, mineral chemistry and whole-rock geochemistry together with magnetic fabrics, structural field relations and age determinations allowed us to describe the crystallization history of these rocks, discuss their evolution from melt generation to magma ascent and emplacement, and form the model of sequence of Variscan...

ENGLISH ABSTRACT We present new results of structural and magnetic (AMS) analyses of selected dikes of melasyenite, quartz melasyenite to melagranite porphyries accompanied by lamprophyres (minettes). The studied dike from the locality Nihošovice were dated by U-Pb method on zircons at 338 Ma. The asymmetric structural pattern of the studied dikes gives an excellent evidence for their emplacement and orientation of magmatic flow. The studied dikes were emplaced into: (i) Prevailing parts of the Central Bohemian Plutonic Complex (locality Malčice) and (ii) host high-grade metamorphic rocks of western part of the Moldanubian Zone (locality Nihošovice). Despite of the extensive area of occurrence, compositional variations and age of emplacement of these dikes are relatively narrow. Their geochemical and petrological compositions broadly correspond to ultrapotassic plutonic rocks (durbachites). The dikes are steeply dipping in trend ~NNW-SSE to ~W-E, with range in width between ~20 and ~25 meters. In general, our results show: (i) A relatively low degree of magnetic anisotropy (P= 1.012 - 1.152); (ii) Mostly oblate (planar) fabric, especially in marginal parts of the intrusive bodies (T= -0.091 - 0.941); (iii) Evidence for subhorizontal magmatic flow trajectory defined for a newtonian magma with typical...

Krkonose-Jizera plutonic complex is one of the largest composite plutonic bodies in the Czech massif. The emplacement of this pluton relates to the origin of the structural and thermal aureole. The processes of contact metamorphism are most evident in the northern and southern part. The topic of this work is to find influence of the contact metamorphism in the host rocks. Partial information about contact metamorphism in this area could be found in several papers, but there aren't work which discuss this topic in detail. Goal of this work is to make complex interpretation of contact metamorphic processes connected with intrusion of the Krkonose-Jizera plutonic complex and use this interpretation for discussion about model of magma intrusion. In rocks of contact aureole of Krkonose-Jizera plutonic complex (KJPC) were identified relicts of Variscan regional metamorphism, connected to creation of regional metamorphic fabric S1 and S2. Original mineral associations and deformation fabrics were in near-contact zone of KJPC 1 km in average in width heterogeneously overprinted by effects of the contact metamorphism, which intensity increases towards the intrusive contact. In the mineral associations of contact-metamorphic rocks appears characteristic minerals such as cordierite and andalusite, rarely...

Composition and texture of the Middle and Late Eocene volcanic, volcaniclastic, and volcanic-sedimentary rocks in the Bijgerd-Kuh e Kharchin area, in the Uromieh-Dokhtar zone northwest of Saveh, Iran, suggest the complexity of the magmatic system that involved multiple eruptions from one or more sources. Hydrated volcanic fragments in hyaloclastic rocks, and the presence of a sequence of shallow and intermediate-depth marine microfossils, suggest that the Middle Eocene units were erupted in a marine basin. The bimodal volcanism of the Late Eocene is distinguished by the presence of four alternating sequences of hyaloclastite lava and ignimbrite. The REE patterns show spatial homogeneity and temporal heterogeneity in the composition of all the Late Eocene sequences, suggesting origination of magma from varying sources that erupted at different times. The trace element distributions of the hyaloclastites and ignimbrites are compatible with those evolved through fractional crystallization of the lower and upper continental crust, respectively.