Os depósitos triássicos da Bacia do Paraná no Brasil ocorrem somente no estado do Rio Grande do Sul, mais precisamente, diretamente sobre a porção centro-sul do Escudo Sul-Rio-Grandense entre os paralelos 30º45‟e 31º15‟S e os meridianos 52º45‟e 53º15‟W. Com o objetivo de definir o modelo sedimentar do tipo inundito para os depósitos triássicos contidos no setor nordeste do Gráben Arroio Moirão realiza-se aqui uma abordagem em termos de estratigrafia de sequências. Para tanto, aplicou-se técnicas de mapeamento geológico de rochas sedimentares, levantamento de seis perfis colunares e coleta de amostras de rochas para análises. Com isso, foram definidas dezoito fácies, oito sucessões de fácies, sete superfícies-chave e dois marcadores estratigráficos, o que corroborou com a elaboração do arcabouço estratigráfico para a região de estudo, bem como, com a proposição do modelo deposicional do tipo inundito. As litologias encontradas na região são invariavelmente mal selecionadas, têm grãos angulosos a subangulosos e possuem geometrias em lençóis ou tabulares, características típicas de tal modelo sedimentar. O modelo de inunditos consiste em fluxos subaquosos episódicos progradantes de baixa densidade que com o passar do tempo passam a desenvolver canais efêmeros, que, por sua vez, ocorrem rapidamente por meio de feições rasas e desconfinantes. Há então a etapa transgressiva, quando o nível de base sobe e o fluxo é afogado e, posteriormente, ocorre exposição subaérea. Assim, deposita-se a sequência sedimentar clássica do modelo tipo inundito: a sucessão de fácies granodecrescente ascendente com depósitos tabulares e em lençóis de conglomerados, maciços ou com estratificação cruzada tangencial, intercalados com camadas de arenitos grossos a conglomeráticos, maciços, ou com estratificação cruzada tangencial, por vezes com intraclastos argilosos, seguidos por depósitos tabulares e em lençóis de arenitos de granulometria média a grossa, maciços ou com estratificação cruzada tangencial, cruzada tabular ou plano‐paralela, podendo também conter intraclastos argilosos. Quando há o desconfinamento, depositam‐se arenitos muito finos a finos com laminação plano‐paralela de fluxo superior, maciços ou com estratificação cruzada de baixo ângulo. Após, têm-se os depósitos tabulares de siltitos e lamitos com laminação plano‐paralelo ou maciço, com intercalações de níveis micáceos e feições de exposição subaérea no topo. / In Brazil, the Triassic deposits of the Paraná Basin only occur in the state of Rio Grande do Sul, more precisely, over the south-central portion of the Sul-Rio-Grandense Shield between the parallels 30º45 'and 31º15' S and 52º45 meridians " and 53º15 "W. In order to define the sedimentary model inundito type for Triassic deposits contained in the northwest sector of the Arroio Moirão Graben is held here an approach in terms of sequence stratigraphy. In selected outcrops, by applying geological mapping techniques it was proposed columnar profiles, photographic documentation and the sampling of the units for further analysis. The columnar profiles allowed the recognition of eighteen facies, eight successions of facies, seven key surfaces and two stratigraphic markers, which corroborated with the development of the stratigraphic framework for the study area as well, with the proposition of the a depositional inundite type model, since the lithology found in the region are invariably bad selected, have angular grains subangular and have geometries sheets or tabular, typical features such sediment model with which it is to subaqueous episodic progradational flows low density with the passage of time. They go on to develop ephemeral channels, which, in turn, occur rapidly through shallow desconfinantes features after they have to transgressive step, when the base level rises and the flow is drowned subsequently occurs subaerial exposure. So is deposited classic sedimentary inundite type model: the succession of fining upward facies with tabular deposits and conglomerates sheets, massive or tangential cross bedding, interspersed with layers of coarse to conglomeratic sandstones, massive or cross-stratification tangential, sometimes with clayey intraclasts, followed by tabular deposits and sheets of medium grained sandstones thick, massive or tangential cross bedding, cross-tabular or plane-parallel, and may also contain clay intraclasts. When there is desconfinamento, deposited in very thin sandstones fine with a parallel lamination higher flow, solid or cross-bedding of low angle. Then, there are the tabular deposits siltstones and mudstones with lamination plane-parallel or massive, interlayered with micaceous levels and subaerial exposure features at the top.

To study the history of processes that shape the Earth’s surface, geologists look for markers in the landscape that they can date and use to measure change. Rivers leave such markers in their deposits and terrace landforms and in the overall shape of their elevation profile from head to toe. This thesis uses luminescence and cosmogenic methods to date the sediment in terraces to determine when the river deposited it. Field mapping and global positioning system (GPS) surveying are also used to measure the distance between terrace levels to quantify how much change has occurred. This study seeks to answer questions about when, how quickly, and why streams near Moab in Utah’s Canyonlands region have incised into bedrock. It seeks also to determine the history, rates, and patterns of the active and incremental sinking of Moab and Spanish valleys. The results from this work show that the incision of canyons along Mill and Pack creeks upstream from Moab accelerated around 200,000 years ago to between 0.44 and 0.62 millimeters per year (mm/yr). The sinking of Moab and Spanish valleys also appears to have quickened around the same time and has occurred at up to 1.35 mm/yr in Moab Valley and around 0.45 mm/yr in Spanish Valley over the last 100,000 years. The Kayenta Heights fault zone (KHFZ) accommodates part of the sinking of Moab Valley and has slipped at an average rate of 0.44 mm/yr in the last 100,000 years. This study’s mapping of the length and width of individual fault strands supports prior interpretations that the KHFZ does not pose an earthquake hazard, though it can still be expected to produce active rock fall and rupture the ground surface locally. That the sinking of Moab and Spanish valleys and the down-cutting of the upstream canyons has occurred at similar rates, and may indeed have sped up at a similar time in the past, indicates a linkage of the two processes. This is consistent with an existing hypothesis that Moab and Spanish valleys are sinking because groundwater is dissolving the buried salt deposits and transporting them out through the Colorado River. This process is able to continue because as the Colorado River and its tributaries incise lower into the landscape, groundwater follows and can reach greater depths in the salt deposits. The results of this study paint a picture of the recent and accelerated sinking of Moab and Spanish valleys, which has occurred jointly with incision of the regional drainage network. This acceleration of incision, which has been documented throughout the Canyonlands region, may relate to the Colorado River’s carving of Grand Canyon around 6 million years ago or may have come from a more recent and unknown downstream source.

Grasshopper basin, located in southwest Montana, is an east-tilted graben bounded by the listric Muddy-Grasshopper fault and the Meriwether Lewis fault on the eastern and western margins of the basin, respectively. This basin contains a complex stratigraphy of intertonguing facies comprised of five unconformity-bounded sequences of Tertiary alluvial, flu vial, deltaic, and lacustrine sedimentary and volcanic rocks. Sequence 1 consists of the Challis volcanic Group (Middle Eocene). The sedimentary rocks of the Medicine Lodge beds (Late Eocene-Late Oligocene) represent sequence 2 and approximately 90% of the basin-fill within Grasshopper basin. Sequence 3 consists 11 of the Sedimentary Rocks of Everson Creek (Late Oligocene-Early Miocene), sequence 4 is represented by the Sedimentary Rocks of Bannack Pass (Middle-Late Miocene), and the Six Mile Creek Formation (Late Miocene?) corresponds to sequence 5. Sequence 2 is the synrift deposit for the Muddy-Grasshopper fault, and was dominated by lakes that filled axially by rivers from the north. Transverse sediment influx was present on small fan-delta complexes shed into the lake from the eastern margin and periodic large fluvial-dominated alluvial fan and deltaic deposition from the western margin. Paleocurrent analyses are consistent with these observations and show predominantly south-southeastward axial paleoflow directions with west-directed and east-directed paleoflow on the eastern and western margins, respectively. Petrologic studies, including sandstone petrography and conglomerate petrology, reveal a mixed "basement uplift" and "recycled orogen" tectonic provenance. These findings support a model for Eocene-Oligocene rifting characterized by moderate to high relief superimposed on the Cretaceous-Early Tertiary Sevier fold-and-thrust belt. Paleogeographic reconstructions of Grasshopper basin reveal the lack of a southern basin margin. A correlation of the basin-fill contained in the Medicine Lodge and Horse Prairie basins to the south with the Medicine Lodge beds (sequence 2) in Grasshopper basin suggests that each of these basins represents a third of a larger preexisting extensional basin that was partially dismembered by later phases of continued extension. Large extensional folds in Grasshopper basin had a small influence on facies architecture in the basin.

Este trabajo de investigación tiene como objetivo determinar el potencial sísmico del sistema de fallas Cofradía, y por consiguiente aportar nuevos datos sobre el grado de peligrosidad sísmica al que puede estar sometida la zona en la que se localiza esta falla. Determinar su peligrosidad sísmica es de suma importancia, dadas las dimensiones de esta falla y la elevada concentración poblacional de la zona de Managua, una ciudad cree de manera desordenada, donde la mayoría de las viviendas no cumplen con los estándares o normas de construcción requerido para zona del Pacifico de Nicaragua. La ciudad esta ubicada a lo interno de una estructura tectónica activa denominada graben de Managua en la que producen sismos con frecuencia. Este graben es la estructura tectónica más activa de Nicaragua, localizada en la denominada Depresión Nicaragüense, un extenso poco profundo de mas de 300 km de longitud y 70 km de ancho, con una orientación NO-SE, atraviesa el territorio nacional en su sector occidental, de manera paralela a la costa del Pacifico. La mala situación económica a la que se enfrenta un alto porcentaje de la población hace que se adquieran materiales de construcción de mala calidad y en muchos casos de segunda mano que de igual manera cumplen con los requisitos de calidad para productos de la rama de la construcción. Ello representa un peligro adicional en el momento de la ocurrencia de un sismo de una cierta magnitud. Todas estas condiciones hacen que la vulnerabilidad en esta zona sea alta; dicha vulnerabilidad junto con la alta peligrosidad sísmica que genera la ocurrencia de sismos fuertes en esta zona los parámetros que determinan su riesgo sismo. El proceso de ejecución a seguir en este estudio pasa por la selección de una zona, en la que se ubica una falla activa en este caso el sistema de fallas Cofradía, a partir de diferentes características: geológicas, geomorfológicas y sísmicas propias de esta falla. A continuación se realiza una recopilación y síntesis de toda la información existente sobre la falla y la zona en la que se ubica la traza de falla, la foto interpretación es una etapa importante, centra en la morfología del terreno en la zona seleccionada esto genera, como resultado la selección de un cierto numero de puntos de interés en los que se observan elementos geomorfológicos (escarpes de fallas, abanicos aluviales, alineamientos) los cuales deben ser estudiados con mayor detalle durante la etapa de campo, para detectar indicadores de actividad geotectónica. Todos los datos de campo obtenidos han de permitir la aplicación de diversos análisis (geomorfológicos, estructural, de la sismicidad y Paleosismicidad) sobre lo que hay que discutir para obtener el resultado esperado. El graben de Managua localizado en el sector Oeste de la depresión Nicaragüense, es la estructura tectónica más activa localizada en el interior de este depresión, con una orientación Norte-Sur, la que se ha considerado como una estructura secundaria, con respecto a la depresión Nicaragüense que la alberga, su relación estructural con la estructural principal no es conocida. El graben de Managua se ha interpretado como una estructura de tipo extensional activa, a la que se le ha adjudicado la separación que se observa en la cadena volcánica cuaternaria. El graben esta limitado tanto en el Oeste como por el este por falla normales de orientación Norte –Sur, una de estas fallas es la falla Cofradía, la que se extiende desde las cercanía del complejo volcánico Masaya en el sur, hacia el Norte a lo largo de 38 km. La falla Cofradía es un sistema de fallas normales que limita el graben de Managua, por su extremo Este, y la depresión del graben del aeropuerto. La falla Cofradía representa una estructura geológica importante, dada su longitud, su conexión con la Caldera del Volcán Masaya, su influencia sobre la anómalamente recta de la costa oriental del Lago de Managua y su cercanía con la ciudad de Managua. Se trata de una falla de 3 km de largo cuya expresión superficial esta bien definida, con la presencia de un escarpe que presenta diferentes alturas a lo largo de toda su longitud. Con el estudio paleosismológico se determinaron cinco eventos sísmicos asociados a esta falla, tres detectados en la trinchera el Cocal, y dos en la de La Vaquería, y detectaron estructuras que revelan al actividad sísmica de la falla, con rupturas de la superficie del terreno: cuñas coluviales y estructuras de licuefacción. Esta falla es capaz de romper en toda su longitud y producir sismos con una Mw próxima a 7. Durante los últimos 1700 años esta estructura ha producido tres sismos lo que han afectado la superficie, con una recurrencia media de 570 años y una tasa de deslizamiento de 1 mm/año.

ABSTRACT NEOTECTONICS OF THE KARAMIK GRABEN-AFYON-(ISPARTA ANGLE), SW TURKEY &Ccedil / i&ccedil / ek, Aydin M.Sc., Department of Geological Engineering Supervisor: Prof. Dr. Ali Ko&ccedil / yigit July 2009, 98 pages The Karamik Graben (KG) is 6-17-km-wide, 29-km-long and NNE-SSWtrending active depression located within the Isparta Angle of the Southwestern Turkey extensional neotectonic domain. The KG is bounded by ENE-SSWtrending Karaca&ouml / ren fault zone to the south, the NNE-SSW-trending Ko&ccedil / beyli- Akkonak fault zone to the east, the WNW-ESE-trending AkSehir fault zone to the north, and the NE-SW to NNE-SSW-trending Devederesi fault zone to the west. The KG contains two graben infills separated by an angular unconformity: (1) Middle Miocene-Middle Pliocene deformed infill, and (2) the Upper Pliocenerecent non-deformed infill. Some geological structures reveal that the older infill was accumulated under the control of an extensional tectonic regime (phase-I extension). Analysis of NW-SE-trending folds and some strike-slip faults indicate that the older infill deformed by a short-term NE-SW-directed compression. This contractional event is the last record of the paleotectonic period. Some geological and geophysical evidence indicate that the younger infill has been deposited under the control of an extensional tectonic regime (phase-II extension). Analysis of some slickensides implies that the current tectonic regime is being characterized by a multi-directional extension in predominantly N-S, E-W and NW-SE directions. This multi-directional extension dominates the Plio- Quaternary neotectonic period initiated Late Pliocene. Total throw amounts accumulated along the margin boundary faults imply that subsidence rates are ~0.15 mm/yr and ~0.21 mm/yr since Late Pliocene. Some of the northern margin-boundary faults of the KG reactivated during the neotectonic period as evidenced by 2002.02.02 Mw = 6.5 &Ccedil / ay earthquake. However, the rest of these faults are still active and they keep their nature of seismic gap.

The Late Jurassic Brae oilfields in the South Viking Graben of the northern North Sea contain naturally high concentrations of carbon dioxide (up to 35 mol %). Fields immediately adjacent to the graben bounding fault display the highest concentrations, with CO2 content decreasing eastward into the basin. It is thought the CO2 was introduced into the region via this fault. This thesis examines the possible source of the high CO2 present in the region, focusing on the graben margin fault as a potential conduit for CO2 flux from depth Investigation of cored sections penetrating the graben bounding fault revealed numerous carbonate cemented fracture arrays. The morphology of the fractures and cements is attributed to hydraulic fracturing induced by episodic release of overpressured fluids up the margin fault from depth. Periods of rapid subsidence omnipresent throughout the tectonic history of the graben are conducive to the generation of overpressure; a feature commonly reported in the region. Samples from the carbonate fracture cements were analysed using a host of techniques, including SEM, EMPA, fluid inclusion, and stable δ13C ‐ δ18O analyses. Using SEM analysis, at least five generations of dolomite cement with concomitant iron sulphide were observed. Cement chemistry and textures indicate precipitation from concentrated CO2–rich fluids. A reported high salinity basinal influx from depth concomitant with proposed CO2 charge into the region ~70 Ma is a probable source for the dissolved solids subsequently precipitated as carbonate in the fracture networks. Fluid inclusion analysis provided sufficient evidence to suggest the influx of hot fluids into the region, presumably sourced from deep in the margin fill. Two distinct δ13C vs. δ18O trends are observed in the isotope data from four wells studied. The trends are interpreted as differential mixing between ascending basinal fluids rich in dissolved inorganic carbon and in situ formation waters dominated by organically derived carbon following the onset of thermal decarboxylation in the Kimmeridge Clay Formation. Dissolution of Zechstein carbonates underlying the region is a credible source for the isotopically heavy CO2 found adjacent to the graben margin (δ13CCO2 = ‐2 to ‐5 ‰) and incorporated into the carbonate cements. Inferred variations in fluid mixing from well to well have implications on the variability of fluid flow along the graben margin with respect to contrasting fault morphologies. A Rayleigh fractionation model accommodating CO2 degassing from a hot ascending isotopically heavy fluid can be invoked to explain the observed carbon‐oxygen isotopic covariations in the fracture cements. Geochemical modelling simulating the ascent of CO2‐rich waters suggests degassing has limited impact on precipitation volumes, with fluid‐rock reactions the most likely driver for extensive carbonate mineralisation observed.

This thesis examines how the growth, interaction and linkage of normal faults, and the broader structural styles within rift basins, provide first-order controls upon syn-rift sediment routing and the development of coeval syn-rift stratigraphy. To achieve this, this thesis integrates observations from an area of active extension, alongside the stratigraphic record of an ancient rift basin. The former allows greater insight into sediment erosion, transport and preservation processes during rifting, whereas the latter represents the net depositional history, hence permitting a reconstruction of rift tectono-stratigraphic evolution. Recent advances in the understanding of landscape response to active faulting, have focused predominantly on large-scale rift provinces or where fault segments are widely-spaced across-strike (~15-30 km). As such, the neotectonic portion of this study integrates field and digitial terrain analysis to examine the geomorphic response to active faulting across the Perachora Peninsula (Gulf of Corinth, Central Greece), an uplifting, faulted-terrace setting. Here, the across-strike fault-spacing is small (~2-3 km), allowing fault segments to interact across-strike, and landscape evolution to be driven by a complex configuration of perched, intermittent and marine base-levels. These base-levels have a propensity to switch, with implications for sediment-routing and hanging-wall stratigraphic development. The preservation potential of sub-aerial syn-rift landscapes and basin-fill is extremely low in settings such as Perachora, due to the aggressive headward cannibalisation driven by ongoing tectonic uplift and short downstream distances to terminal base level. The subsurface stratigraphic study examines the Triassic-Jurassic syn-rift stratigraphy of the Danish Central Graben, an area displaying lateral variability in the original thickness and mobility of Late Permian Zechstein evaporites along-strike of the bounding Coffee-Soil Fault System. This setting enables a direct comparison between evaporite-influenced and non- evaporite-influenced rifting at a range of scales. By integrating observations of variability in structural style, with a systematic seismic-stratigraphic analysis of the syn-rift interval, the study documents how interactions between normal fault evolution and mobile evaporites influence: i) the variability in rift basin structural style; ii) the development of stratal geometries; and iii) the nature and location of depositional systems. On a basin-wide scale, the evaporite-influenced rift portions display more prominent fault-related and evaporite-related folding, which in turn controls syn-rift deposition, along with variable degrees of decoupling of basement and cover fault and fold systems. Focusing on the evaporite-influenced Coffee-Soil Fault System, variations in the locations and rates of accommodation generated by both load-driven withdrawal of evaporites up the hanging-wall dip-slope, and fault-related subsidence, provide a critical, and hitherto neglected control upon dip- and strike-oriented variability in hanging-wall stratigraphic architecture. Conceptual models for the development of hanging-wall stratigraphy, incorporating the influence of sediment supply rates upon load-induced evaporite mobilisation, provide a framework which may be used in the analysis of evaporite-influenced border fault systems worldwide. Overall, the findings of this thesis have implications for understanding the controls on spatial and temporal variability in structural style, sediment routing and syn-rift stratigraphic evolution in rift basins. In particular, the study highlights that to determine a deeper understanding of the interactions which determine the evolution of syn-rift stratigraphy, it is essential to examine basin processes in both modern and ancient rift settings, as well as at a range of scales.

Os depósitos triássicos da Bacia do Paraná no Brasil ocorrem somente no estado do Rio Grande do Sul, mais precisamente, diretamente sobre a porção centro-sul do Escudo Sul-Rio-Grandense entre os paralelos 30º45‟e 31º15‟S e os meridianos 52º45‟e 53º15‟W. Com o objetivo de definir o modelo sedimentar do tipo inundito para os depósitos triássicos contidos no setor nordeste do Gráben Arroio Moirão realiza-se aqui uma abordagem em termos de estratigrafia de sequências. Para tanto, aplicou-se técnicas de mapeamento geológico de rochas sedimentares, levantamento de seis perfis colunares e coleta de amostras de rochas para análises. Com isso, foram definidas dezoito fácies, oito sucessões de fácies, sete superfícies-chave e dois marcadores estratigráficos, o que corroborou com a elaboração do arcabouço estratigráfico para a região de estudo, bem como, com a proposição do modelo deposicional do tipo inundito. As litologias encontradas na região são invariavelmente mal selecionadas, têm grãos angulosos a subangulosos e possuem geometrias em lençóis ou tabulares, características típicas de tal modelo sedimentar. O modelo de inunditos consiste em fluxos subaquosos episódicos progradantes de baixa densidade que com o passar do tempo passam a desenvolver canais efêmeros, que, por sua vez, ocorrem rapidamente por meio de feições rasas e desconfinantes. Há então a etapa transgressiva, quando o nível de base sobe e o fluxo é afogado e, posteriormente, ocorre exposição subaérea. Assim, deposita-se a sequência sedimentar clássica do modelo tipo inundito: a sucessão de fácies granodecrescente ascendente com depósitos tabulares e em lençóis de conglomerados, maciços ou com estratificação cruzada tangencial, intercalados com camadas de arenitos grossos a conglomeráticos, maciços, ou com estratificação cruzada tangencial, por vezes com intraclastos argilosos, seguidos por depósitos tabulares e em lençóis de arenitos de granulometria média a grossa, maciços ou com estratificação cruzada tangencial, cruzada tabular ou plano‐paralela, podendo também conter intraclastos argilosos. Quando há o desconfinamento, depositam‐se arenitos muito finos a finos com laminação plano‐paralela de fluxo superior, maciços ou com estratificação cruzada de baixo ângulo. Após, têm-se os depósitos tabulares de siltitos e lamitos com laminação plano‐paralelo ou maciço, com intercalações de níveis micáceos e feições de exposição subaérea no topo. / In Brazil, the Triassic deposits of the Paraná Basin only occur in the state of Rio Grande do Sul, more precisely, over the south-central portion of the Sul-Rio-Grandense Shield between the parallels 30º45 'and 31º15' S and 52º45 meridians " and 53º15 "W. In order to define the sedimentary model inundito type for Triassic deposits contained in the northwest sector of the Arroio Moirão Graben is held here an approach in terms of sequence stratigraphy. In selected outcrops, by applying geological mapping techniques it was proposed columnar profiles, photographic documentation and the sampling of the units for further analysis. The columnar profiles allowed the recognition of eighteen facies, eight successions of facies, seven key surfaces and two stratigraphic markers, which corroborated with the development of the stratigraphic framework for the study area as well, with the proposition of the a depositional inundite type model, since the lithology found in the region are invariably bad selected, have angular grains subangular and have geometries sheets or tabular, typical features such sediment model with which it is to subaqueous episodic progradational flows low density with the passage of time. They go on to develop ephemeral channels, which, in turn, occur rapidly through shallow desconfinantes features after they have to transgressive step, when the base level rises and the flow is drowned subsequently occurs subaerial exposure. So is deposited classic sedimentary inundite type model: the succession of fining upward facies with tabular deposits and conglomerates sheets, massive or tangential cross bedding, interspersed with layers of coarse to conglomeratic sandstones, massive or cross-stratification tangential, sometimes with clayey intraclasts, followed by tabular deposits and sheets of medium grained sandstones thick, massive or tangential cross bedding, cross-tabular or plane-parallel, and may also contain clay intraclasts. When there is desconfinamento, deposited in very thin sandstones fine with a parallel lamination higher flow, solid or cross-bedding of low angle. Then, there are the tabular deposits siltstones and mudstones with lamination plane-parallel or massive, interlayered with micaceous levels and subaerial exposure features at the top.

Made available in DSpace on 2015-03-13T17:08:26Z (GMT). No. of bitstreams: 1 AjosenildoNS_1_40.pdf: 1272278 bytes, checksum: 9b1c1c8f6612afc587e4f349ec301a5d (MD5) Previous issue date: 2009-09-04 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The Rio do Peixe Basin is located in the border of Para?ba and Cear? states, immediately to the north of the Patos shear zone, encompassing an area of 1,315 km2. This is one of the main basins of eocretaceous age in Northeast Brazil, associated to the rifting event that shaped the present continental margin. The basin can be divided into four sub-basins, corresponding to Pombal, Sousa, Brejo das Freiras and Icozinho half-grabens. This dissertation was based on the analysis and interpretation of remote sensing products, field stratigraphic and structural data, and seismic sections and gravity data. Field work detailed the lithofacies characterization of the three formations previously recognised in the basin, Antenor Navarro, Sousa and Rio Piranhas. Unlike the classical vertical stacking, field relations and seismostratigraphic analysis highlighted the interdigitation and lateral equivalency between these units. On bio/chrono-stratigraphic and tectonic grounds, they correlate with the Rift Tectonosequence of neocomian age. The Antenor Navarro Formation rests overlies the crystalline basement in non conformity. It comprises lithofacies originated by a braided fluvial system system, dominated by immature, coarse and conglomeratic sandstones, and polymict conglomerates at the base. Its exposures occur in the different halfgrabens, along its flexural margins. Paleocurrent data indicate source areas in the basement to the north/NW, or input along strike ramps. The Sousa Formation is composed by fine-grained sandstones, siltites and reddish, locally grey-greenish to reddish laminated shales presenting wavy marks, mudcracks and, sometimes, carbonate beds. This formation shows major influence of a fluvial, floodplain system, with seismostratigraphic evidence of lacustrine facies at subsurface. Its distribution occupies the central part of the Sousa and Brejo das Freiras half-grabens, which constitute the main depocenters of the basin. Paleocurrent analysis shows that sediment transport was also from north/NW to south/SE / A Bacia do Rio do Peixe est? situada no limite dos estados da Para?ba e do Cear?, imediatamente a norte do Lineamento Patos, com ?rea de aproximadamente 1.315 km2. Esta ? uma das principais bacias de idade eocret?cea no interior do Nordeste do Brasil, associadas ao rifteamento que moldou a atual margem continental. A bacia pode ser dividida em quatro sub-bacias, as quais correspondem aos semi-grabens de Pombal, Sousa, Brejo das Freiras e Icozinho. Esta disserta??o foi baseada em an?lises e interpreta??es de produtos de sensores remoto, levantamentos estratigr?ficos e dados estruturais de terreno, al?m de linhas s?smicas e dados gravim?tricos. Trabalhos de campo detalharam a caracteriza??o faciol?gica das tr?s forma??es previamente distinguidas na bacia, Antenor Navarro, Sousa e Rio Piranhas. Ao contr?rio do empilhamento estratigr?fico cl?ssico, vertical, as rela??es de campo e a an?lise sismoestratigr?fica evidenciaram as interdigita??es e equival?ncia lateral entre essas unidades. Do ponto de vista bio/cronoestratigr?fico e tect?nico, as mesmas se correlacionam com a Tectonossequ?ncia Rifte neocomiana. A Forma??o Antenor Navarro repousa em n?o conformidade sobre o embasamento cristalino e compreende litof?cies originadas por um sistema fluvial entrela?ado, dominado por arenitos de granulometria grossa a conglomer?ticos, imaturos, e conglomerados polim?ticos na base. As exposi??es desta forma??o ocorrem em todos os semi-grabens, ao longo de suas margens flexurais. Dados de paleocorrente indicam deposi??o a partir de ?reas fontes no embasamento, a norte/NW, ou a partir de rampas direcionais. A Forma??o Sousa ? composta por arenitos de granulometria fina, siltitos e folhelhos avermelhados e localmente cinza-esverdeados, laminados, com presen?a de marcas onduladas, gretas de contra??o e, por vezes, n?veis carbon?ticos. Esta forma??o denota a influ?ncia predominante de um sistema fluvial, com infer?ncia (sismoestratigr?fica) de f?cies lacustre em subsuperf?cie. A sua distribui??o abrange principalmente a parte central dos semi-grabens de Sousa e de Brejo das Freiras, que constituem os principais depocentros da bacia. A an?lise das paleocorrentes mostra que o transporte dos sedimentos tamb?m ocorreu de norte/NW para sul/SE.A Forma??o Rio Piranhas ? composta por arenitos arcosianos de granulometria grossa, com intercala??es de brechas e conglomerados polim?ticos, depositados por sistemas de leques aluviais. As exposi??es desta forma??o ocorrem principalmente nas margens falhadas dos semi-grabens, sendo mais restritas na Sub-bacia de Icozinho. As paleocorrentes orientam-se predominantemente no sentido de norte/NW para sul/SE, ou em disposi??o axial acompanhando paleoescarpas de dire??o NE/SW. Nos diferentes compartimentos da bacia, esta unidade interdigita-se com as forma??es Sousa e Antenor Navarro, ratificando a deposi??o sintect?nica do conjunto. A an?lise estrutural da Bacia do Rio do Peixe, tamb?m baseada em dados de campo e interpreta??o de se??es s?smicas, mostra que as principais falhas representam a reativa??o fr?gil de zonas de cisalhamento pr?-cambrianas. Tais falhas, normais ou de rejeito obl?quo (normal sinistral para a dire??o E-W), delimitam os semi-grabens e compartimentos internos. O levantamento de dados estruturais permitiu detalhar a cinem?tica dessas falhas e inferir eixos de strain e o regime de esfor?os atuantes na evolu??o da bacia. O levantamento s?smico 2D realizado nos semi-grabens de Brejo das Freiras e de Sousa possibilitou a visualiza??o da geometria em cunha dos refletores, que apresentam basculamento para sul/SE, controlado pelas falhas de borda. O arranjo interno dos refletores evidencia a atua??o sindeposicional (at? sinlitifica??o) dos falhamentos, como por exemplo o espessamento de camadas e o recobrimento de degraus por estratos mais jovens. S?o observadas a presen?a de sinclinais e anticlinais geradas pela combina??o do basculamento com a geometria l?strica, os degraus e o arrasto das falhas. O degrau de Santa Helena perfaz o seu limite sul como uma rampa derevezamento e tamb?m se articula com o semi-graben de Sousa. A falha de S?o Gon?alo, com orienta??o E-W e mergulho para norte, define o limite sul do semigraben de Sousa. Internamente a este segundo semi-graben foram identificados dois depocentros limitados por uma falha normal com dire??o NE-SW e mergulho para NW, adjacente a um alto interno no qual ocorrem ind?cios de ?leo. O principal depocentro, a NW dessa falha, deve atingir 2,0 km de profundidade.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-31T23:12:19Z No. of bitstreams: 1 MoisesSamuelJoaoBotaCacama_DISSERT.pdf: 15699529 bytes, checksum: bf8851e1234bc09c6a2f37eb37638d6e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-05T19:22:45Z (GMT) No. of bitstreams: 1 MoisesSamuelJoaoBotaCacama_DISSERT.pdf: 15699529 bytes, checksum: bf8851e1234bc09c6a2f37eb37638d6e (MD5) / Made available in DSpace on 2016-04-05T19:22:45Z (GMT). No. of bitstreams: 1 MoisesSamuelJoaoBotaCacama_DISSERT.pdf: 15699529 bytes, checksum: bf8851e1234bc09c6a2f37eb37638d6e (MD5) Previous issue date: 2015-05-25 / O Lineamento Transbrasiliano ? uma importante zona de cisalhamento com dire??o NE-SW, relacionada orog nese Brasiliana e que evoluiu em est?gios de alta at? baixa temperatura. No presente trabalho, investigou-se a assinatura estrutural e geof?sica da por??o norte do Lineamento Transbrasiliano (fronteira Cear?-Piau?), envolvendo a zona milon?tica brasiliana, o Graben de Jaibaras e as reativa??es que afetam as sequ?ncias sedimentares p?s-ordovicianas da Bacia do Parna?ba. Na literatura ? comum a refer?ncia ? reativa??o fanerozoica dessa estrutura, a qual teria originado diversos grabens tardi-brasilianos precedentes ? sin?clise paleozoica do Parna?ba, a exemplo do Graben de Jaibaras. As falhas que seccionam as unidades estratigr?ficas da Bacia do Parna?ba, ao longo de toda a extens?o do Lineamento Transbrasiliano, exprimem a sua reativa??o em eventos mais jovens. O mapa do campo magn?tico an?malo reduzido ao polo exibe anomalias com dire??o NE, interpretadas como a assinatura do Lineamento Transbrasiliano (e das estruturas brasilianas da Prov?ncia Borborema) na sua express?o de alta temperatura. O Graben de Jaibaras ? marcado por uma faixa an?mala retil?nea com alta susceptilidade magn?tica (interpretada como o predom?nio de rochas ferromagnesianas, provavelmente vulc?nicas), aparentemente sem continuidade expressiva no substrato da Bacia do Parna?ba. A an?lise geom?trica e cinem?tica das estruturas da ?rea enfocada, utilizando dados de sensores remotos e de campo, permitiu a caracteriza??o de quatro fases de deforma??o fr?gil a d?ctil-fr?gil Dn, D1, D2 e D3. A fase deformacional Dn, de idade ediacarana-cambriana, ocorre de modo exclusivo no Graben de Jaibaras, com desenvolvimento de estruturas de temperatura mais elevada (comparativamente aos eventos mais jovens), d?cteis-fr?geis. As fases deformacionais D1, D2 e D3 ocorrem afetando tanto o Graben de Jaibaras como as sequ?ncias paleozoicas da borda NE da Bacia do Parna?ba, com gera??o de estruturas em temperatura baixa, basicamente r?pteis/catacl?sticas. A an?lise de imagens SRTM permitiu cartografar diversos lineamentos de dire??o NE, NW e E-W na Bacia do Parna?ba, cuja correla??o com as estruturas mesosc?picas ? discutida em termos da reativa??o do Lineamento Transbrasiliano em associa??o com os est?gios de abertura do Atl?ntico e separa??o Am?rica do Sul-?frica, ou mesmo a eventos orog?nicos distais no Paleozoico. / The Transbrasiliano Lineament is a major shear zone trending NE-SW, related to the Brasiliano orogeny and evolved through high to low temperature stages. In this study, the structural and geophysical signature of the northern segment of Transbrasiliano Lineament was studied in its northern border, between Cear? and Piau? states, involving the Brasiliano mylonite zone, the Jaibaras Graben and reactivations affecting the sedimentary sequences post-ordovician of Parna?ba Basin. In the literature, is commonly the phanerozoic reactivation of this structure referred, generating several late Brasiliano grabens predating the paleozoic Parna?ba syneclises, like the Jaibaras Graben. Faults that cut the stratigraphic units of the Parna?ba Basin along the entire length of the Transbrasiliano Lineament express its reactivation during younger events. The magnetic anomaly field reduced to the pole map exhibit anomalies NE-trending, interpreted as the signature of the Transbrasiliano Lineament (and Brasiliano structures of the Borborema Province) in its high-temperature expression. The Jaibaras Graben is marked by a straight anomalous track with high magnetic susceptibility (interpreted as a prevalence of ferromagnesian rocks, probably volcanic), apparently without significant continuity in the substrate of Parna?ba Basin. The geometric and kinematic analysis of the structures in the study area, using remote sensing and field data, led to the characterization of four deformation phases brittle the ductilebrittle Dn, D1, D2 and D3. The Dn deformation phase of ediacaran-cambrian age, occurs exclusively in the Jaibaras Graben, with the development of comparatively higher temperature (as regards to younger events) ductile-brittle structures. D1, D2 and D3 deformation phases affect both the Jaibaras Graben as well as the paleozoic sequences of the northeastern edge of Parna?ba Basin, generating structures developed at lower temperatures, basically brittle/cataclastic. The SRTM image analysis allowed mapping different NE, NW and E-W trending lineaments in Parna?ba Basin, whose correlation with mesoscopic structures is discussed in terms of the reactivation of Transbrasiliano Lineament in association with the stages of general Atlantic opening and separation between South America and Africa, or even the distal orogenic events in Paleozoic.