The Gulf of California and its surrounding land areas provide a classic example of recently rifted continental lithosphere. The recent tectonic history of eastern Baja California has been dominated by oblique rifting that began at ~12 Ma. Thus, extensional tectonics, bedrock lithology, long-term climatic changes, and evolving surface processes have controlled the tectono-geomorphological evolution of the eastern part of the peninsula since that time. In this study, digital elevation data from the Shuttle Radar Topography Mission (SRTM) from Baja California were corrected and enhanced by replacing artifacts with real values that were derived using a series of geostatistical techniques. The next step was to generate accurate thematic geologic maps with high resolution (15-m) for the entire eastern coast of Baja California. The main approach that we used to clearly represent all the lithological units in the investigated area was objectoriented classification based on fuzzy logic theory. The area of study was divided into twenty-two blocks; each was classified independently on the basis of its own defined membership function. Overall accuracies were 89.6 %, indicating that this approach was highly recommended over the most conventional classification techniques. The third step of this study was to assess the factors that affected the geomorphologic development along the eastern side of Baja California, where thirty-four drainage basins were extracted from a 15-m-resolution absolute digital elevation model (DEM). Thirty morphometric parameters were extracted; these parameters were then reduced using principal component analysis (PCA). Cluster analysis classification defined four major groups of basins. We extracted stream length-gradient indices, which highlight the differential rock uplift that has occurred along fault escarpments bounding the basins. Also, steepness and concavity indices were extracted for bedrock channels within the thirty-four drainage basins. The results were highly correlated with stream length-gradient indices for each basin. Nine basins, exhibiting steepness index values greater than 0.07, indicated a strong tectonic signature and possible higher uplift rates in these basins. Further, our results indicated that drainage basins in the eastern rift province of Baja California could be classified according to the dominant geomorphologic controlling factors (i.e., faultcontrolled, lithology-controlled, or hybrid basins).

Οι επαναλαμβανόμενες σεισμικές δονήσεις στη περιοχή, και ειδικότερα μετά τους σεισμούς στις 10/10/2001 (3,9 βαθμοί της κλίμακας Ρίχτερ) και στις 23/11/2011 (3,3 βαθμοί της κλίμακας Ρίχτερ), οι οποίοι προκάλεσαν εμφανείς ζημίες και οδήγησαν στο να κριθούν κτίρια της περιοχής ακατοίκητα, έγειραν το γεωλογικό ενδιαφέρον. Πιο συγκεκριμένα στόχος της παρούσας εργασίας είναι η χρήση μορφομετρικών δεικτών για τον υπολογισμό της ενεργότητας του ρήγματος. / Application of morphotectonic criteria for the qualitative and quantitative determination of the tectonic activity on the mountain range front segment, which is formed north – east of Arfara town, located in Messinia, southern – western part of Peloponnese.

Η εργασία αυτή έγινε με σκοπό την εφαρμογή μορφοτεκτονικών κριτηρίων για τον ποσοτικό και ποιοτικό καθορισμό της τεκτονικής ενεργότητας των δύο μεγάλων προπόδων οροσειράς (mountain range front) που αναπτύσσονται στις δυτικές παρυφές του Αργολικού Πεδίου, ΒΔ της πόλης του Άργους, και η σύγκριση των τιμών των γεωμορφολογικών δεικτών που μετρήθηκαν με την βοήθεια ψηφιακών μοντέλων εδάφους διαφορετικής ανάλυσης (resolution) για την εξαγωγή συμπερασμάτων σχετικά με την ακρίβεια της κάθε μεθόδου. Αφορμή υπήρξε η διαρκώς αυξανόμενη ενασχόληση φοιτητών (προπτυχιακών και μεταπτυχιακών) με ψηφιοποίηση τοπογραφικών χαρτών για δημιουργία Ψηφιακών Μοντέλων Εδάφους (DTM) – μια διαδικασία επίπονη και εξαιρετικά χρονοβόρα – παρότι δεδομένα διατίθενται εύκολα μέσω διαδικτύου (NASA) για DTM για όλο τον κόσμο με σχετικά καλή ανάλυση. Οι δύο πρόποδες είναι συνεχόμενοι αλλά παρουσιάζουν διαφορετική διεύθυνση με τον πρώτο να έχει διεύθυνση ΒΒΔ-ΝΝΑ και μήκος περίπου 6,5 km και τον δεύτερο ΔΒΔ-ΑΝΑ ενώ έχει μήκος περίπου 12,5 km. Για την ανάλυση της ενεργότητας των πρόπoδων οροσειράς εφαρμόστηκαν οι κατάλληλοι γεωμορφολογικοί δείκτες, όπως ο δείκτης της κατά βάθος και κατά πλάτος διάβρωσης χειμάρρων ή λόγος πλάτους προς ύψους κοιλάδας (Ratio of valley-floor width to valley height index, Vf) και ο δείκτης ευθυγράμμισης του πρόποδα (Mountain front sinuosity index, Smf) ενώ παράλληλα εξετάστηκαν και άλλοι γεωμορφολογικοί δείκτες όπως ο δείκτης Μήκους – κλίσης ρέμματος (Stream-length gradient index, SL) και ο δείκτης Υψομετρικής καμπύλης-Υψομετρικού ολοκληρώματος (Hypsometric Curve / Hypsometric Integral). Για την μέτρηση των τιμών των δεικτών χρησιμοποιήθηκαν δύο ψηφιακά μοντέλα εδάφους διαφορετικής ανάλυσης (resolution) που αναπτύχθηκαν με διαφορετικές μεθοδολογίες, ένα λεπτομερές από ψηφιοποίηση τοπογραφικών χαρτών κλίμακας 1:5000 της ΓΥΣ και ένα πιο προσεγγιστικό χαμηλότερης ανάλυσης από δορυφορικά δεδομένα SRTM, με την βοήθεια λογισμικών GIS. Τα αποτελέσματά συγκρίθηκαν με την βοήθεια διαγραμμάτων. Όσον αφορά το ζήτημα της ενεργότητας της προπόδων οροσειράς από τα αποτελέσματα των μετρήσεων προκύπτει ότι αυτοί είναι ενεργοί καθώς παρουσιάζουν χαμηλές τιμές του δείκτη Vf και Smf. Οι τιμές τους (μετρημένες από το λεπτομερές Ψ.Μ.Ε.) κυμαίνονται από 0,0531 μέχρι 0,7668 (Vf) και 1,3645 (Smf) για τον πρώτο πρόποδα και από 0,02 μέχρι 9,3 (Vf) και 1,3526 (Smf) για τον δεύτερο πρόποδα. Επίσης με την βοήθεια του δείκτη SL εντοπίστηκαν δύο σημεία που σε συνδυασμό με την τοπογραφία υποδεικνύουν πιθανά ενεργά ρήγματα που δεν έχουν χαρτογραφηθεί. Η χρησιμοποίηση του δείκτη του υψομετρικού ολοκληρώματος κατατάσσει την λεκάνη του χειμάρρου Ξηριά, που βρίσκεται πίσω από τον πρώτο πρόποδα, στο ‘στάδιο ωριμότητας’, κάτι που φαινομενικά έρχεται σε αντίθεση με τους υπόλοιπους δείκτες αλλά μάλλον οφείλεται στην μορφολογική διαμόρφωση της λεκάνης πίσω από τον πρόποδα που σχετίζεται περισσότερο από τεκτονικές και όχι από διαβρωτικές διεργασίες. Όσον αφορά την σύγκριση των αποτελεσμάτων που προκύπτουν από τα δύο διαφορετικά ψηφιακά μοντέλα εδάφους οι μετρήσεις τιμών του δείκτη SL και του Υψομετρικού Ολοκληρώματος μπορούν να γίνουν εξίσου καλά και από τα δύο. Για τον δείκτη Vf οι μετρήσεις που γίνονται με την βοήθεια του πιο προσεγγιστικού μοντέλου είναι γενικά μεγαλύτερες ενώ δεν μπορεί να γίνουν μετρήσεις για ρέμματα 1ης ή 2ης τάξης κατά Strahler. Οι διαφορές στις τιμές του δείκτη Vf που παρατηρούνται μεταξύ των δύο μοντέλων εκμηδενίζονται όταν η μέτρηση του πλάτους της κοίτης μπορεί να προκύψει με αντικειμενικό τρόπο (π.χ. μέτρηση από ορθοφωτοχάρτες). Για τον δείκτη Smf προκύπτει ότι όσο μικρότερο είναι το μήκος του πρόποδα τόσο μικρότερη είναι η απόκλιση στις μετρήσεις του δείκτη Smf από το αδρομερέστερο μοντέλο καθώς είναι πιο περιορισμένη η απόκλιση της παραμέτρου Lmf λόγω ‘απλοποιήσεων’ των γραμμών. / The aim of this MSc thesis is the application of morphotectonic criteria for the qualitative and quantitative determination of the tectonic activity on two mountain range fronts segments, which are formed in the western part of Argolis plain, in the eastern Peloponnese. We also tried to measure and compare values of the geomorphological indices obtained from DTM’s of different resolution, in order to extract conclusions for the accuracy of the two different models. The two mountain front segments are almost continuous and they display different orientation in strike: the first has a NNW-SSE strike and a length of 6.5 km and the second one has a WNW-ESE strike and a length of 12.5 km. In order to examine the activity of the two range fronts we applied the suitable geomorphic indices, such as the ratio of valley-floor width to valley height index (Vf), the mountain front sinuosity index (Smf), as well as other indices such as the stream-length gradient index (SL) and the hypsometric curve-hypsometric integral index. For the calculation of these indices we used two DTM’s of different resolution, which were constructed from different approached methodologies: a more detailed DTM from digitization of topographic maps of the Hellenic Military Geographical Service, in 1:5000 scale, and a less detailed DTM from SRTM-data downloaded from NASA, all modeled with standard GIS software. The results of the two models were compared with various diagrams. Regarding the activity of the range front segments, our data show that they are both active since they display low values of Vf and Smf indexes. Their values (measured from the finer DTM) vary from 0,05 to 0,77 (Vf) and 1,3645 (Smf) for the first segment and from 0,02 to 9,3 (Vf) and 1,3526 (Smf) for the second segment. Additionally, using the SL-index we observed two zones, which when correlated with the modern topography seem to indicate two unmapped and possibly active fault zones. The Xerias basin, which is formed behind the 1st range fault segment, appears to be in the “maturity stage” using the hypsometric integral index, a fact that contradicts with the other index results. This is may be due more to tectonic than erosional processes. Finally, from the comparison of the different DTM we suggest that calculation of SL and hypsometric integral index can be made with similar accuracy. For the Vf , the SRTM data display higher values, while calculation of 1st and 2nd order gullies (sensu Strahler) cannot be directly measured. Differences in the Vf values from the two DTM models can be eliminated significantly when we calculate the width of the valley from ortho-photomaps. Regarding the Smf index, it seems that we obtain less accurate results, as the length of the range front increases, due to the over-simplification of the shape of the elevation contours compared to the real topographic data.

Die Sierras Pampeanas in Zentral- und Nordwestargentinien stellen ein ausgeprägtes morphotektonisches Merkmal im Bereich der flach subduzierenden Nazca Platte unter die Südamerikanische Platte zwischen ~27° S und ~33° S dar. Diese flache Subduktion wurde bisher als Ursache für die Heraushebung und Deformation von Höhenzügen innerhalb der Sierras Pampeanas während des Neogens angenommen. Auf Basis von Apatit Spaltspurendatierungen, Zirkon und Apatit (U-Th)/He Thermochronometern sowie K-Ar Datierungen von Störungsletten werden in der vorliegenden Arbeit neue thermochronologische Daten vorgestellt, deren Interpretation eine veränderte Modellvorstellung bezüglich der thermischen, strukturellen und morphotektonischen Entwicklung der argentinischen Sierras Pampeanas aufzeigt. So ist die Abkühlung unter ~175 °C in den Östlichen und Westlichen Sierras Pampeanas auf eine Permo-Triassische flache Subduktion innerhalb dieser Bereiche zurückzuführen, während die Entwicklung des nördlichen Teils des Arbeitsgebietes davon nicht beeinflusst wurde. Im allgemeinen fand während des Mesozoikums weiterhin Abkühlung und Exhumation statt. Nur lokal begrenzte Gebiete, wie z.B. die Sierra de El Gigante, erfuhren eine Wiedererwärmung durch Sedimentablagerung in Riftbecken, die durch Extension im Bereich von reaktivierten spätpaläozoischen Hauptstrukturen gebildet wurden. Die finale Abkühlung und Exhumation zu oberflächennahen Temperaturen erfolgte in den Östlichen und Westlichen Sierras Pampeanas zwischen der späten Kreide und dem Paläogen, wodurch die Theorie, dass diese Bereiche schon seit mindestens der späten Kreide durch ein positives Relief charakterisiert waren, das während des Neogens nur noch unwesentlich weiter ausgebildet wurde, unterstützt wird. Dieses widerspricht der bisher postulierten Modellvorstellung, dass die Heraushebung der pampeanischen Höhenzüge im wesentlichen durch die andine, flache Subduktion begründet sei. Der Bereich der nördlichen Sierras Pampeanas ist dem gegenüber durch eine känozoische Abkühlungsgeschichte charakterisiert, die durch die Heraushebung des Puna Plateaus beeinflusst gewesen ist. In diesem Gebiet geht der finalen Abkühlung und Exhumation im späten Miozän eine Wiedererwärmung, bedingt durch Sedimentablagerung, während des Paläogens und des frühen Neogens voraus.

Submitted by Jadson Francisco de Jesus SILVA (jadson@uefs.br) on 2018-01-24T22:18:50Z No. of bitstreams: 1 Documnento final corregido.pdf: 12597297 bytes, checksum: 02116050b523c30d85f26b7819a459ef (MD5) / Made available in DSpace on 2018-01-24T22:18:50Z (GMT). No. of bitstreams: 1 Documnento final corregido.pdf: 12597297 bytes, checksum: 02116050b523c30d85f26b7819a459ef (MD5) Previous issue date: 2016-04-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The Serinha?m estuary is located in the south of Bahia state, about 110km from Salvador, within the limits of the Ituber? municipality, between parallels 13 ? 30 'and 14 ? 00' South latitude and meridians 38 ? 50 ' and 39 ? 40 'West longitude, ending up in the Camamu Bay. It is located on the coastal part of the Environmental Protection Area (APA acronym in portuguese) of Pratigi inside the Ecopolo III. Exist in this area a low level of development of human activities, compared with other estuaries from Brazil and over the world. At the same time, it was found a lack of environmental studies, such as salinity and tidal estuary. In this work we studied the behavior of salinity in the estuary of Serinha?m, starting from the understanding of salt exchange process between the river and the sea. The study was approached from a systemic point of view, considering the different components of physical and geographical environment, hydrology, climate, morphology, oceanography, etc., in the regional and local context in which it is inserted. It was divided into three stages; first a literature review and survey of initial data, following later by collection of salinity and tidal data during five campaigns occurred in April, July and December 2014, August and September 2015. The salinity?s samples were collected at 137 stations along the estuary, with an optical refractometer and a multiparameter device Hanna. The tide stations were placed on the docks of Ituber? and Barra Serinha?m ports, using first two rules of tide and in the second measurement, three prototypes of autonomous automatic ultrasonic digital tide gauges, constructed and electronically calibrated in the lab. Finally, we done the office works, where the results of data collected were processed and represented in a GIS environment. It was concluded that there is a difference in salinity? seasonal behavior of the estuary, and that the presence of extreme events such as "El Ni?o" and "La Ni?a" can influence the behavior of salinity. Four elements rules the salinity of the estuary, the morphotectonic that controls the relief of the bottom; the tributaries; the tide and rainfall. The tides were classified as microtidal in December 2014 and August 2015; and as mesotidal in September 2015, due to the influence of syzygy tides during the spring equinox. The estuary was classified according to the salinity as positive; according to the flow rate, as thoroughly mixed and by the movement patterns as well blended or vertically homogeneous. These results are expected to contribute to future updates of the management plans of APA-Pratigi. / O estu?rio de Serinha?m est? situado no baixo sul do estado da Bahia, aproximadamente a 110Km de Salvador, dentro dos limites do munic?pio de Ituber?, entre os paralelos 13?30' e 14?00' de latitude Sul e meridianos 38?50' e 39?40' de longitude Oeste, desembocando na Ba?a de Camamu. Encontra-se na parte costeira da ?rea de Prote??o Ambiental (APA) do Pratigi, dentro do Ec?polo III. Nesta zona existe um baixo n?vel de desenvolvimento das atividades antr?picas em compara??o com outros estu?rios, do Brasil e do mundo. Ao mesmo tempo foi constatada a escassez de estudos ambientais, como salinidade e mar? do estu?rio. Neste trabalho estudou-se o comportamento da salinidade no estu?riodo Serinha?m, a partir da compreens?o do processo de interc?mbio salino entre o rio e o mar. O estudo foi abordado do ponto de vista sist?mico, considerando os diferentes componentes do meio f?sico-geogr?fico, hidrografia, clima, morfologia, oceanografia, etc., no contexto regional e local onde est? inserido. Foi dividido em tr?s etapas, primeiramente a revis?o bibliogr?fica e levantamento de dados iniciais, posteriormente foi realizada coleta de dados de salinidade e mar?, em cinco campanhas nos meses de abril, julho e dezembro de 2014, agosto e setembro de 2015. As amostras de salinidade foram coletadas em 137 esta??es ao longo do estu?rio, com um Refract?metro ?tico e um aparelho multipar?metroHanna. As esta??es de mar? foram colocadas nos Cais dos Portos de Ituber? e da Barra do Serinha?m, utilizando primeiramente dois r?guas de mar? e na segunda medi??o, 3 prot?tipos de mare?grafos digitais ultrass?nicos autom?ticos aut?nomos, constru?dos e calibrados eletronicamente no laborat?rio. Por ?ltimo os trabalhos de gabinete, onde foram processados os resultados das coletas de dados e espaceados num ambiente SIG. Foi poss?vel concluir que existe uma diferen?a no comportamento sazonal da salinidade do estu?rio, a presen?a de eventos extremos como ?El Ni?o? e ?La Ni?a? podem condicionar o comportamento da salinidade. Quatro elementos controlam a salinidade do estu?rio, a morfotect?nica que controla o relevo de fundo; os rios afluentes; a mar? e as precipita??es. As mar?s foram classificadas como micromar?s em dezembro de 2014 e agosto de 2015, e setembro de 2015 como mesomar?, pela influ?ncia das mar?s de siz?gia equinociais de primavera. O estu?rio foi classificado segundo a salinidade como positivo; segundo a taxa de fluxo, como totalmente misturado e pelos padr?es de circula??o comobem misturado ou verticalmente homog?neo. Com esses resultados, espera-se contribuir para as futuras atualiza??es dos planos de manejo da APA-Pratigi.

As cuestas são definidas como uma forma de relevo dissimétrico, composta por uma vertente em declive íngreme de um lado e uma rampa em declive suave no reverso, decorrente da erosão diferencial das rochas. A região da Serra de São Pedro/SP, área de ocorrência de basaltos juro-cretáceos (topo da escarpa) e arenitos eólicos (escarpa e glacis) do Triássico ao Cretáceo Médio, consiste em uma das zonas mais típicas das cuestas na Bacia do Paraná, porém a configuração geometrizada do relevo da área, do sistema fluvial e até do baixo rio Piracicaba sugerem um controle tectônico das formas. Nesse sentido, o objetivo deste trabalho foi verificar o possível controle tectônico no relevo da Serra de São Pedro e do Baixo Piracicaba, focalizando a ação da Neotectônica, tendo como hipótese a existência de um forte controle das estruturas modernas sobre as formas. Os resultados mostraram que a atividade neotectônica na área é caracterizada principalmente pela atividade de falhas transcorrentes e normais subverticais WNW-ESE, W-E, NW-SE e NE-SW, ambas de pequeno rejeito e de impacto reduzido na morfologia do relevo. A influência das estruturas nas formas é mais intensa no sistema fluvial, comandando a dissecação do relevo de toda a área a partir de linhas estruturais que correspondem aos planos de juntas, grandes fraturamentos e falhas, ainda que a tectônica recente seja responsável pelo controle da direção apenas dos canais de 1º e 2º ordens. A Neotectônica condiciona ainda a formação de facetas triangulares na frente da escarpa da Serra de São Pedro, provoca perturbações de depósitos fluviais quaternários, anomalias no perfil longitudinal dos rios e inflexões dos interflúvios e canais de drenagem, além de pequenos basculamentos de blocos que causam a formação e degradação de terraços fluviais nos afluentes da margem direita do baixo Piracicaba. Essas informações são coerentes com os dados das estruturas medidas e materiais descritos em campo, bem como com as informações do contorno estrutural e dados geofísicos da área. Apesar do claro registro de neotectônica na região da Serra de São Pedro e do Baixo Piracicaba, os resultados demonstraram que a magnitude dessa atividade é reduzida e o seu impacto no relevo é pequeno, sendo que a configuração geomorfológica atual é mais influenciada por fatores litológicos, pela disposição das camadas sedimentares das rochas, pelos (paleo)climas e pela orientação/distribuição de estruturas tectônicas anteriores ao Neógeno, refutando assim a hipótese inicial do trabalho. / Cuestas are asymmetric landforms characterized by a steep slope along the plateau front and a gentle slope on its reverse, and they are interpreted as a relief formed by differential erosion of rocks. The São Pedro Ridge (Serra de São Pedro)/SP region, area with occurrence of juro-cretacic basalts (top of the ridge) and Triassic medium Cretaceous aeolian sandstone (scarp and glacis), is one of the most typical examples of the cuestas in the Paraná Basin. Although São Pedro Ridge is considered a cuesta, the geomorphological settings and the fluvial system (including the Lower Piracicaba River) of the area suggest a tectonic control on the landforms. Thus, the aim of this research was to verify a possible tectonic control on the São Pedro Ridge and Lower Piracicaba River landforms, emphasizing the Neotectonic influence. The hypothesis is that modern tectonics has a strong influence in the actual landforms. The results showed that the neotectonic activity in the study area is characterized mainly by sub-vertical strike-slip and normal faults WNW-ESE, WE, NW-SE and NE-SW, both with very small offsets and inconspicuous impact in the relief. The influence of the tectonic activity in the landforms is more intense in the fluvial system, controlling the relief dissection from joint planes, large fractures and faults, though modern tectonics is responsible for the control of the direction only of first and second order drainage channels. Neotectonics also controls the formation of triangular facets at the escarpment front of the São Pedro Ridge, faulting in quaternary fluvial deposits, anomalies in the longitudinal profiles of streams and changes in the direction of ridge lines and watercourses (river bends), as well as small block tilting which influences the formation and degradation of fluvial terraces of the Piracicaba right margin tributaries. These interpretations are coherent with the data set concerning the structures measured and materials characterized in the field, as well as with the information about the structural contour and geophysical data of the area. Despite the clear record of neotectonics in the São Pedro Ridge and Lower Piracicaba River region, the results demonstrated that the magnitude of the modern tectonic activity is small, and that the actual geomorphological configuration is more influenced by lithological factors, paleoclimates and the arrangement of sedimentary rock layers and pre-Neogene tectonic structures, thus refuting the initial hypothesis of this study.

Le Venezuela est traversé par une zone de limite de plaque. Ce système tectonique accommode les mouvements relatifs de trois plaques majeures: la plaque Sud-Américaine, la plaque Caraïbe et la plaque de Nazca. Ce système est constitué de failles décrochantes actives qui ont généré au Venezuela de nombreux séismes de magnitude supérieure à 6-7. Parmi ces failles, cette thèse se focalise sur la faille de Boconó et la faille d’El Pilar.Le but de cette thèse est d'étudier l'activité de ces failles sur plusieurs échelles de temps en utilisant une approche multidisciplinaire qui combine analyses morphotectonique, paléosismologique et géodésique. Cette approche a permis de préciser le régime de déformation de ces failles indispensable à l'estimation de l'aléa sismique.Antérieurement à cette thèse, dans la région de Yaracuy, l’activité tectonique du segment nord de la faille de Boconó était mal contrainte faute de données géodésiques ou géochronologiques suffisantes. Or cette partie de la faille a provoqué en 1812 un séisme de Mwi 7.4 qui a détruit les villes de la région.Grâce à la datation par Béryllium-10 de la surface d’exposition de cônes alluviaux décalés par la cinématique dextre de la faille, cette thèse montre que la vitesse quaternaire de la faille est comprise entre 5.0 et 11.2 mm/an.En comparant cette vitesse estimée sur ~ 200 ka et le taux de glissement estimé en champ lointain par des mesures géodésiques (~ 12 mm/an), il peut être proposé que la faille de Boconó accommode une grande partie de l'extrusion du Bloc Nord Andin. La réalisation de carte de vitesses moyennes de déformation à partir d'images SAR a montré l'absence de glissement asismique le long de la faille de Boconó entre 2007 et 2011. En extrapolant ce comportement aux derniers 200 ans, il en résulte que, depuis le dernier séisme en 1812 il y a une accumulation de déficit de glissement de quelques mètres selon la vitesse de glissement considérée. Cette faille représente donc un aléa sismique important pour la région. Une tranchée réalisée pour préciser cet aléa a montré que trois évènements sismiques de Mw > 6-6.5 ont lieu depuis 1300 ap. J.-C., le dernier de ces événements étant probablement le séisme historique de 1812.Au Nord Est du Venezuela, la faille d’El Pilar accommode l’intégralité du mouvement relatif entre la plaque Sud-Américaine et la plaque Caraïbe (~ 20 mm/an). Après le séisme de Ms 6.8 en 1997, le segment émergé de cette faille a subit un important « afterslip ». Des mesures géodésique réalisées en 2003, 2005 et 2013 ont montré que ce segment glisse encore asismiquement (~12 – 13 mm/an). Cette thèse présente une carte des vitesses de déformation entre 2007 et 2011 calculée par interférométrie radar. Celle-ci a permis de montrer que cette faille glisse asismiquement de façon non uniforme dans l’espace et le temps. L’analyse en série temporelle des déplacements a révélé que le glissement asismique de certains tronçons de la faille subit une accélération en Juin 2009 avec des vitesses de glissement asismiques supérieures au déplacement relatif entre les plaques. Cette observation permet d’interpréter que le glissement asismique a un comportement transitoire, en effet, des périodes de blocage et des périodes de larges glissements se succèdent. Cette succession doit probablement se poursuivre tout le long de la période intersismique comme le suggèrent le faible nombre de séismes historiques et préhistoriques au regard de la vitesse de coulissage le long de la faille. Enfin ce glissement asismique présentant des variations spatiales et temporelles est probablement contrôlé par la présence de serpentinites et d’une activité hydrothermale le long de la zone de faille, contexte connu pour favoriser des comportements rhéologiques de ce type. / Venezuela is crosscut by a plate boundary zone, this tectonic setting accommodates the relative displacements of three plates: the South America, the Caribbean and the Nazca Plate. This tectonic system is constituted of active strike-slip faults which have provoked several events of Mw > 6-7. Among these faults, this thesis focuses on the Boconó Fault and on the El Pilar Fault.The aim of this dissertation is to study fault activities on several time scales using a multidisciplinary approach. This approach, which combines morphotectonic, paleoseismologic and geodetic analyses, leads to clarify the deformation pattern. This knowledge is essential to the seismic hazard assessment.Previously to this thesis, in the Yaracuy valley, the tectonic activity of the Boconó fault was poorly constrained due to the lack of geodetic and geochronological data; although a part of this fault triggered in 1812 an earthquake of Mwi 7.4. Through 10-Beryllium surface exposition dating of two alluvial fans shifted by the fault, this thesis shows that the Quaternary slip rate of the fault ranges from 5.0 to 11.2 mm/yr. By comparing this rate estimated on ~ 200 ka with the slip rate estimated in far field with geodesy (~ 12 mm/yr), it can be proposed that the Boconó fault accommodates a major part of the North Andean Block extrusion. Velocity map of ground displacements calculated using SAR images shows the lack of aseismic slip along the Boconó Fault during the 2007-2011 period. The extrapolation of this locked activity since the 1812 event, implies that there is a slip deficit of several meters. Therefore, the Boconó Fault have to be taken into account in the regional seismic hazard assessment. A paleoseismological trench across the studied segment is also presented in this thesis in order to constrain this assessment. Three events of Mw > 6 - 6.5 have been recorded in this trench since 1300 CE, the last of these events is probably the 1812 historical earthquake.In the north-western region of Venezuela, the El Pilar Fault accommodates the whole relative displacement between South-America and Caribbean Plates (~ 20 mm/yr). After the last event in 1997 (Ms 6.8) the on-shore segment of this fault undergoes an important afterslip. Geodetic campaign measurements performed in 2003, 2005 and 2013 showed that this segment was still creeping (~ 12 - 13 mm/yr). This thesis presents an InSAR analysis performed with 18 SAR images spanning the 2007-2011 period. The velocity map shows that the aseismic slip is not uniform along the El Pilar Fault. Time-series analysis reveals locally a creep acceleration. This transient is characterised by a rate exceeding the rate of surrounding plate motion. Therefore, the El Pilar fault seems to be partially locked during several years and then undergoes transient creep during several months. This succession should last during the whole interseismic period as suggested by the low seismic activity and paleoseismological trenches. This creep showing spatio-temporal variations is probably controlled by the existence of serpentinites lenses and the hydrothermal activity, which are known to promote this kind of rheological behaviour.

Submitted by Rafael Santana (rafael.silvasantana@ufpe.br) on 2017-05-09T17:11:19Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação de mestrado - Adriana Cassiano da Silva.pdf: 103902408 bytes, checksum: 64f18d5ee39468da48f4a2f055b735ca (MD5) / Made available in DSpace on 2017-05-09T17:11:19Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação de mestrado - Adriana Cassiano da Silva.pdf: 103902408 bytes, checksum: 64f18d5ee39468da48f4a2f055b735ca (MD5) Previous issue date: 2016-02-16 / CAPES / A reconstrução quaternária da evolução do baixo curso do rio Capibaribe está baseada em abordagens geomorfológicas, morfométricas e morfotectônicas, associados ao uso das geotecnologias, bem como na aplicação da abordagem relativa à tectônica sedimentar no município de Paudalho-PE. O objetivo dessa pesquisa é caracterizar a dinâmica fluvial a partir da investigação dos corpos sedimentares, que configuram elementos marcadores da paisagem, para entender os processos deposicionais da área e esclarecer a relação entre tectônica e o cenário estabelecido na drenagem, uma vez que, essa modalidade de pesquisa traz novas respostas para a compreensão da evolução recente da região. Para tanto, as amostras de sedimentos deformados foram coletadas em seis perfis e subdivididas em 30 “janelas” em depósitos de conglomerados e de linhas de pedras, sendo, após isso, submetidas às análises granulométricas, morfoscópicas e de difratometria de raios-X. Assim, a compilação dos mapeamentos de detalhe e analises sedimentológicas propiciaram uma modelagem mais precisa da área investigada. Os resultados permitiram evidenciar os seguintes fatos: o curso fluvial foi submetido a distintos graus de controle estrutural em escala regional, com a presença da captura do rio em uma direção de falha e brusca inflexão para o sul, trechos anômalos da drenagem e mudança em sua hierarquia; a análise morfotectônica permitiu constatar que as feições de knick-points, inselbergues, vales e cristas estão possivelmente sob o comando estrutural tectônico; os depósitos de conglomerados e de linhas de pedras apresentaram origem sedimentar alóctone, sendo o primeiro, com características fluviais, onde os grãos apresentam imaturidade textural, são pobremente selecionados, com padrão polido e translúcido, contendo seixos rolados e no segundo o aspecto principal é a evidência de clima mais seco. Esses depósitos sugerem interferência de controle estrutural e oscilação paleoclimática no seu arranjo deposicional e na distribuição espacial. Logo, as coberturas sedimentares e as feições morfotectônicas foram originadas em eventos distintos de basculamentos comandando a rede de drenagem e seu nível de base, assim como, a deposição dos depósitos, o que faz deduzir que o forte controle na estrutura física do relevo sugere reconfiguração tectônica. / Quaternary reconstruction of the evolution of the lower course of the Capibaribe river is based on geomorphological, morphometric and morphotectonic approaches associated with the use of geotechnology, and the implementation of the approach to sedimentary tectonics in Paudalho-PE municipality. The objective of this research is to characterize the fluvial dynamics from the investigation of sedimentary bodies that shape the landscape marker elements to understand the depositional processes of the area and clarify the relationship between tectonics and the scenery established in the drainage, since this modality research brings new answers for understanding the recent evolution in the region. Therefore, samples of deformed sediments were collected in six profiles and subdivided into 30 "windows" in deposits of conglomerates and stone lines, and after that, subjected to morphoscopic, granulometric and X-ray diffractometry analysis. Thus, the compilation of detailed mappings and sedimentological analysis provided a more accurate modeling of the investigated area. The results have highlighted the following facts: the fluvial course has been subjected to different degrees of structural control on a regional scale, with the presence of the river capture in one failure direction and sharp inflection to South, anomalous drainage passages and change in their hierarchy; morphotectonic analysis has allowed that the features of knick-points, inselbergs, valleys and ridges are possibly under the tectonic structural command; deposits of conglomerates and stones lines showed allochthonous sedimentary origin, the first with fluvial features, where the grains have not textural maturity, being poorly selected, with polished and translucent standard, containing pebbles and the second main aspect is the evidence of drier climate.These deposits suggest interference of structural control and paleoclimatic fluctuation in their depositional arrangement and spatial distribution. Thus, the sedimentary cover and the morphotectonic features have been originated in different events of tiltings commanding the drainage system and its base level, as well as the deposition of deposits, which makes deduce that the strong control of the physical relief structure suggests reconfiguration tectonics.

As cuestas são definidas como uma forma de relevo dissimétrico, composta por uma vertente em declive íngreme de um lado e uma rampa em declive suave no reverso, decorrente da erosão diferencial das rochas. A região da Serra de São Pedro/SP, área de ocorrência de basaltos juro-cretáceos (topo da escarpa) e arenitos eólicos (escarpa e glacis) do Triássico ao Cretáceo Médio, consiste em uma das zonas mais típicas das cuestas na Bacia do Paraná, porém a configuração geometrizada do relevo da área, do sistema fluvial e até do baixo rio Piracicaba sugerem um controle tectônico das formas. Nesse sentido, o objetivo deste trabalho foi verificar o possível controle tectônico no relevo da Serra de São Pedro e do Baixo Piracicaba, focalizando a ação da Neotectônica, tendo como hipótese a existência de um forte controle das estruturas modernas sobre as formas. Os resultados mostraram que a atividade neotectônica na área é caracterizada principalmente pela atividade de falhas transcorrentes e normais subverticais WNW-ESE, W-E, NW-SE e NE-SW, ambas de pequeno rejeito e de impacto reduzido na morfologia do relevo. A influência das estruturas nas formas é mais intensa no sistema fluvial, comandando a dissecação do relevo de toda a área a partir de linhas estruturais que correspondem aos planos de juntas, grandes fraturamentos e falhas, ainda que a tectônica recente seja responsável pelo controle da direção apenas dos canais de 1º e 2º ordens. A Neotectônica condiciona ainda a formação de facetas triangulares na frente da escarpa da Serra de São Pedro, provoca perturbações de depósitos fluviais quaternários, anomalias no perfil longitudinal dos rios e inflexões dos interflúvios e canais de drenagem, além de pequenos basculamentos de blocos que causam a formação e degradação de terraços fluviais nos afluentes da margem direita do baixo Piracicaba. Essas informações são coerentes com os dados das estruturas medidas e materiais descritos em campo, bem como com as informações do contorno estrutural e dados geofísicos da área. Apesar do claro registro de neotectônica na região da Serra de São Pedro e do Baixo Piracicaba, os resultados demonstraram que a magnitude dessa atividade é reduzida e o seu impacto no relevo é pequeno, sendo que a configuração geomorfológica atual é mais influenciada por fatores litológicos, pela disposição das camadas sedimentares das rochas, pelos (paleo)climas e pela orientação/distribuição de estruturas tectônicas anteriores ao Neógeno, refutando assim a hipótese inicial do trabalho. / Cuestas are asymmetric landforms characterized by a steep slope along the plateau front and a gentle slope on its reverse, and they are interpreted as a relief formed by differential erosion of rocks. The São Pedro Ridge (Serra de São Pedro)/SP region, area with occurrence of juro-cretacic basalts (top of the ridge) and Triassic medium Cretaceous aeolian sandstone (scarp and glacis), is one of the most typical examples of the cuestas in the Paraná Basin. Although São Pedro Ridge is considered a cuesta, the geomorphological settings and the fluvial system (including the Lower Piracicaba River) of the area suggest a tectonic control on the landforms. Thus, the aim of this research was to verify a possible tectonic control on the São Pedro Ridge and Lower Piracicaba River landforms, emphasizing the Neotectonic influence. The hypothesis is that modern tectonics has a strong influence in the actual landforms. The results showed that the neotectonic activity in the study area is characterized mainly by sub-vertical strike-slip and normal faults WNW-ESE, WE, NW-SE and NE-SW, both with very small offsets and inconspicuous impact in the relief. The influence of the tectonic activity in the landforms is more intense in the fluvial system, controlling the relief dissection from joint planes, large fractures and faults, though modern tectonics is responsible for the control of the direction only of first and second order drainage channels. Neotectonics also controls the formation of triangular facets at the escarpment front of the São Pedro Ridge, faulting in quaternary fluvial deposits, anomalies in the longitudinal profiles of streams and changes in the direction of ridge lines and watercourses (river bends), as well as small block tilting which influences the formation and degradation of fluvial terraces of the Piracicaba right margin tributaries. These interpretations are coherent with the data set concerning the structures measured and materials characterized in the field, as well as with the information about the structural contour and geophysical data of the area. Despite the clear record of neotectonics in the São Pedro Ridge and Lower Piracicaba River region, the results demonstrated that the magnitude of the modern tectonic activity is small, and that the actual geomorphological configuration is more influenced by lithological factors, paleoclimates and the arrangement of sedimentary rock layers and pre-Neogene tectonic structures, thus refuting the initial hypothesis of this study.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-06-28T14:57:01Z No. of bitstreams: 1 thaianecamposmoura.pdf: 5403600 bytes, checksum: 8ce1a14d3d84f8dc8e5add1439b93dcf (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-07T21:19:10Z (GMT) No. of bitstreams: 1 thaianecamposmoura.pdf: 5403600 bytes, checksum: 8ce1a14d3d84f8dc8e5add1439b93dcf (MD5) / Made available in DSpace on 2017-08-07T21:19:10Z (GMT). No. of bitstreams: 1 thaianecamposmoura.pdf: 5403600 bytes, checksum: 8ce1a14d3d84f8dc8e5add1439b93dcf (MD5) Previous issue date: 2017-05-05 / A presente dissertação se propôs à investigar as implicações da morfotectônica na organização da paisagem na bacia hidrográfica do Rio Preto (RJ/MG), cuja localização corrobora para a análise de feições morfotectônicas entre duas unidades geomorfológicas do sudeste brasileiro, o Alinhamento de Cristas do Paraíba do Sul e o Planalto do Itatiaia. Diante dos objetivos traçados foram selecionadas técnicas morfométricas de aplicação sobre o relevo e a drenagem, representações cartográficas e incursões a campo, que conjuntamente à Fisiologia da Paisagem, em seus três níveis de abordagem, ampararam o entendimento sobre a o quadro morfoestrutural e morfotectônico presente no recorte espacial selecionado. As feições registradas em campo e os resultados coletados em laboratório apontam conjuntamente para a atividade neotectônica concomitante à dinâmica superficial da paisagem comum em regiões tropicais, que muitas vezes mascara feições de uma tectônica passiva sobre a paisagem. Resultados concretos alcançados revelam a neotectônica atualmente no Sudeste brasileiro, corroborando para feições paisagísticas morfotectônicas. / This dissertation proposes to investigate the implications of dynamic neotectonic in the organization of the landscape in Rio Preto basin (RJ/MG), whose location supports for analyzing morphotectonic features between two geomorphological units of southeastern Brazil, the Alinhamento de Cristas do Paraíba do Sul and the Planalto do Itatiaia. Before the objectives were selected for morphometric techniques application on the topography and drainage, cartographic representations and raids the countryside, which jointly to the physiology of the landscape, in its three levels of approach, bolstered the understanding about the dynamics showed this in the space selected clipping. The features recorded in the field and the results collected in laboratory point together to neotectonic activity concomitant to the superficial common landscape dynamics in tropical regions, which often masks a passive tectonic features on the landscape, but in many of the results it was possible to show that the study area is located in a dynamic tectonic framework.