Les failles décrochantes se caractérisent par des géométries 3D relativement complexes, avec des changements abrupts de structures associés à une segmentation latérale. Ainsi, comprendre comment les failles décrochantes sont segmentées latéralement peut apporter des informations sur la répartition de la déformation et des contraintes le long de ces failles ou encore leur comportement sismique. Dans cette étude nous avons cherché à caractériser ces paramètres pour la faille du Levant. Dans un premier temps nous nous sommes intéressés au comportement sismique de cette faille au cours des derniers millénaires. Pour cela, nous avons réalisé une tranchée paléosismologique le long de la section sud de la faille où les données sur la sismicité historique restent limitées. Cela nous a permis de proposer un scénario de rupture pour la section entre le golfe d’Aqaba et le Mont Liban (~500 km). Le catalogue obtenu montre que la faille a connu plusieurs crises sismiques d’environ 200 ans, durant lesquelles l’ensemble de la faille rompt en cascade, séparées par des périodes de quiescence d’environ 350-400 ans, suggérant que la sismicité suit un modèle de clustering temporel. Ce catalogue nous a également permis d’estimer le déficit de glissement accumulé au cours des derniers 1600 ans. Ce déficit, est homogène pour toute la section de faille considérée, à 2 m de moyenne, ce qui pourrait suggérer l’imminence d’une crise sismique régionale, puisque que la compensation d’un tel déficit se traduirait par l’occurrence d’un séisme de Mw ~7.2 sur chaque section de faille. Dans une deuxième partie, nous avons étudié la répartition de la déformation à long terme dans une zone présentant une géométrie relativement complexe : le golfe d’Aqaba. Dans cette région, nous avons cartographié à partir de données de terrain et d’images satellites un certain nombre de structures secondaires sur les marges du golfe. Ainsi, même si la faille principale se trouve en mer, une partie de la déformation verticale est accommodée à terre. La confrontation des datations thermochronologiques et cosmogéniques réalisées le long de la côte Est du golfe montre une accélération des taux de soulèvement à partir de 5 Ma, qui est interprétée comme une conséquence de la migration du pôle d’Euler associé à la rotation de la plaque Arabique. Cette migration a favorisé un régime transtensif dans le golfe d’Aqaba, entrainant la réactivation de failles anciennes bordant la plaine côtière. Enfin, afin d’évaluer les mécanismes contrôlant la segmentation des failles décrochantes et leur évolution dans le temps, nous avons réalisé des expériences analogiques en boite à sable. Elles nous ont permis de mettre en avant (1) l’impact majeur de l’épaisseur du matériel cassant sur la longueur des segments et (2) la pérennité de la segmentation des failles décrochantes, puisque la segmentation observée sur le terrain obéit aux mêmes lois d’échelle que la segmentation observée aux stades initiaux de déformation dans les boites à sable / Strike slip faults are characterised by complex 3D geometries, with abrupt structural variations and a high degree of lateral segmentation. Hence, understanding the underlying mechanisms of lateral fault segmentation can shed light on the distribution of deformation and stress along these faults, as well as their seismic behaviour. In this study, we have tried to characterise some of these parameters for the Levant fault. We first investigated the seismic behaviour of this fault over the last few thousand years. To do this we realised a paleoseimological trench along the southern section of the fault, in a region where historical seismic data are limited. This allowed us to propose a rupture scenario for the section running from the Gulf of Aqaba to Mount Lebanon (~500km). The resulting catalogue highlights several seismic crises about 200 years long during which the whole fault ruptures in a cascade, interspaced with quiescent periods of about 350-400 years. This suggests that the seismic behaviour of the fault presents temporal clustering. Our catalogue also allowed for the estimation of the slip deficit accumulated over the last 1600 years in the considered section. This deficit is homogeneous along the fault and relatively high (2 m on average), which could suggest that a seismic crisis could happen over the entire region in a near future, as the compensation of such deficit would require the occurrence of a Mw 7.2 event on each section of the fault. After that we studied the distribution of long-term deformation in a region with a relatively complex geometry: the Gulf of Aqaba. In this region we mapped from field data and satellite images several secondary structures on the margins of the gulf. Indeed, even though the main fault is at sea, part of the vertical deformation is accommodated on land. The confrontation of thermochronological and cosmogenic datations along the eastern coast of the gulf shows an acceleration of the uplift rates. We interpret this as a consequence of the migration of the Euler pole associated with the rotation of the Arabian plaque, 5 ky ago. This migration led to an increase of the transtension in the Gulf of Aqaba, which reactivated ancient faults bordering the coastal plain. Finally, in order to quantify the mechanisms controlling the segmentation of strike slip faults and their temporal evolution, we realised sand box experiments. Our results highlight the importance of the thickness of the brittle material and its impact on the segment lengths. They also show the persistence of strike slip faults segmentation since the segmentation observed in the field obeys the same scaling laws as that observed at the early stages of deformation in sand box experiments

The Charleston Uplift (CU), a 30-km-long by 7-km-wide, N46°E-oriented subsurface geologic anomaly in the northern Mississippi embayment near Charleston, Missouri, exhibits up to 36 m of vertical relief across the Paleogene/Quaternary unconformity. Subsurface structural relief, along with the CU’s coincident boundary alignment with contemporary microseismicity and the New Madrid North Fault (NMNF), suggest a structural origin. Subsequent seismic soundings indicate vertical structural relief is present in Cretaceous and Paleozoic horizons, supporting the fault-controlled origin. The southern boundary (CU-s) had not been investigated, nor had any direct fault images been acquired. Integrated microgravity and seismic-reflection methods across the inferred CU-s establish the first image of this fault. Forward modeling indicated that the vertical variation of strata across the CU-s would induce a microgravity anomaly of 1.6 mGal. The observed microgravity anomaly survey across the southern boundary is 1.616 ± .004 mGal, and is consistent with the tectonic interpretation. A subsequently acquired seismic-reflection profile corroborates this interpretation. The imaged fault shows approximately 60, 35, and 35 meters of vertical down-to-the-south throw across the tops of Paleozoic, Cretaceous, and Tertiary horizons, respectively. This confirms the CU is not an erosional feature, but a structurally controlled extension of the NMNF.

Ingeniera Civil Industrial / La eficiencia y efectividad de las campañas en la industria del retail financiero son de suma importancia debido a la cantidad de actores en el rubro. Primero, es fundamental en la realización de campañas la existencia de un grupo de control que permita evitar que las apariencias lleven a conclusiones erróneas. Segundo, ¿todos necesitan recibir la campaña para que tengan el comportamiento deseado?, es probable que la respuesta sea no. Debido a lo anterior, se propone mejorar la eficiencia de las campañas de súper avances a través del perfilamiento de clientes que efectivamente se pueden persuadir con diferentes estímulos de marketing. Esto último se pretende lograr mediante la implementación de modelos uplift, que tienen como resultado la segmentación de los clientes en 4 grupos: los influenciables, los seguros, las causas perdidas y los sleeping dogs, quienes reaccionan de manera contraria al comportamiento deseado. Esta segmentación se conoce como la segmentación fundamental de las campañas y es de suma importancia al momento de hacer una, ya que su implementación mejora las tasas de respuesta incrementales, reduce los costos, reduce los efectos negativos del marketing y mejora la comunicación con los clientes. Es importante mencionar que para la confección de los modelos uplift es necesario la realización de experimentos que permitan obtener la data necesaria con un grupo de control adecuado. Primero, la confección de los experimentos tiene la finalidad de testear dos cosas: 1) si el sugerir un posible uso del crédito mejora los resultados de una campaña y 2) responder qué tipo de estímulo es mejor para las diferentes categorías de clientes. De lo anterior se concluye que el sugerir un uso del crédito no afecta significativamente las tasas de respuesta y además, que independiente de que los clientes elite (clientes de alto valor para la empresa) respondan significativamente mejor cuando se trata de un regalo de puntos, los clientes en general no siempre mejoran sus tasas de respuesta cuando se les ofrece algún gancho. Una vez realizados los modelos (uno para las campañas genéricas, otro para puntos y otro para giftcard), se concluye que no es necesario enviar estímulos a todos los clientes, es decir, efectivamente existe un óptimo de clientes a tocar, los que me permitirán obtener los beneficios mencionados anteriormente. Finalmente, se recomienda a la empresa utilizar siempre un grupo de control adecuado y además, utilizar el modelo confeccionado evitando así el hostigar a los clientes. Es importante considerar que pasado un tiempo prudente, los modelos necesitarán ser calibrados nuevamente debido al cambio de las condiciones de las campañas. / 23/10/2022

Active continental margins are affected by complex feedbacks between tectonic, climate and surface processes, the intricate relations of which are still a matter of discussion. The Chilean convergent margin, forming the outstanding Andean subduction orogen, constitutes an ideal natural laboratory for the investigation of climate, tectonics and their interactions. In order to study both processes, I examined marine and lacustrine sediments from different depositional environments on- and offshore the south-central Chilean coast (38-40°S). I combined sedimentological, geochemical and isotopical analyses to identify climatic and tectonic signals within the sedimentary records. The investigation of marine trench sediments (ODP Site 1232, SONNE core 50SL) focused on frequency changes of turbiditic event layers since the late Pleistocene. In the active margin setting of south-central Chile, these layers were considered to reflect periodically occurring earthquakes and to constitute an archive of the regional paleoseismicity. The new results indicate glacial-interglacial changes in turbidite frequencies during the last 140 kyr, with short recurrence times (~200 years) during glacial and long recurrence times (~1000 years) during interglacial periods. Hence, the generation of turbidites appears to be strongly influenced by climate and sea level changes, which control on the amount of sediment delivered to the shelf edge and therewith the stability of the continental slope: more stable slope conditions during interglacial periods entail lower turbidite frequencies than in glacial periods. Since glacial turbidite recurrence times are congruent with earthquake recurrence times derived from the historical record and other paleoseismic archives of the region, I concluded that only during cold stages the sediment availability and slope instability enabled the complete series of large earthquakes to be recorded. The sediment transport to the shelf region is not only driven by climate conditions but also influenced by local forearc tectonics. Accelerating uplift rates along major tectonic structures involved drainage anomalies and river flow inversions, which seriously altered the sediment supply to the Pacific Ocean. Two examples for the tectonic hindrance of fluvial systems are the coastal lakes Lago Lanalhue and Lago Lleu Lleu. Both lakes developed within former river valleys, which once discharged towards the Pacific and were dammed by tectonically uplifted sills at ~8000 yr BP. Analyses of sediment cores from the lakes showed similar successions of marine/brackish deposits at the bottom, covered by lacustrine sediments on top. Dating of the transitions between these different units and the comparison with global sea level curves allowed me to calculate local Holocene uplift rates, which are distinctly higher for the upraised sills (Lanalhue: 8.83 ± 2.7 mm/yr, Lleu Lleu: 11.36 ± 1.77 mm/yr) than for the lake basins (Lanalhue: 0.42 ± 0.71 mm/yr, Lleu Lleu: 0.49 ± 0.44 mm/yr). I hence considered the sills to be the surface expression of a blind thrust associated with a prominent inverse fault that is controlling regional uplift and folding. After the final separation of Lago Lanalhue and Lago Lleu Lleu from the Pacific, a constant deposition of lacustrine sediments preserved continuous records of local environmental changes. Sequences from both lakes indicate a long-term climate trend with a significant shift from more arid conditions during the Mid-Holocene (8000 – 4200 cal yr BP) to more humid conditions during the Late Holocene (4200 cal yr BP – present). This trend is consistent with other regional paleoclimatic data and interpreted to reflect changes in the strength/position of the Southern Westerly Winds. Since ~5000 years, sediments of Lago Lleu Lleu are marked by numerous intercalated detrital layers that recur with a mean frequency of ~210 years. Deposition of these layers may be triggered by local tectonics (i.e. earthquakes), but may also originate from changes in the local climate (e.g. onset of modern ENSO conditions). During the last 2000 years, pronounced variations in the terrigenous sediment supply to both lakes suggest important hydrological changes on the centennial time-scale as well. A lower input of terrigenous matter points to less humid phases between 200 cal yr B.C. - 150 cal yr A.D., 900 - 1350 cal yr A.D. and 1850 cal yr A.D. to present (broadly corresponding to the Roman, Medieval, and Modern Warm Periods). More humid periods persisted from 150 - 900 cal yr A.D. and 1350 - 1850 cal yr A.D. (broadly corresponding to the Dark Ages and the Little Ice Age). In conclusion, the combined investigation of marine and lacustrine sediments is a feasible method for the reconstruction of climatic and tectonic processes on different time scales. My approach allows exploring both climate and tectonics in one and the same archive, and is largely transferable to other active margins worldwide. / An aktiven Kontinentalrändern wirken komplexe Rückkopplungen zwischen Tektonik, Klima- und Oberflächenprozessen, deren Zusammenhänge bisher nur in Grundzügen verstanden und Gegenstand aktueller Forschung sind. Der chilenische Kontinentalrand – mit den Anden als größtem Subduktionsorogen der Erde – bietet ein natürliches Labor zur Erforschung von Klima und Tektonik sowie deren Wechselbeziehungen. Um beide Prozesse genauer zu verifizieren, habe ich marine und lakustrine Sedimente entlang der südlichen Küste Zentralchiles (38-40°S) untersucht und die enthaltenen klimatischen und tektonischen Signale mit einer Kombination aus sedimentologischen, geochemischen und Isotopen-Analysen identifiziert. Die Untersuchung der marinen Trenchsedimente (ODP-Bohrung 1232, SONNE-Kern 50SL) konzentriert sich dabei auf Änderungen in der Ablagerungsfrequenz von turbiditischen Lagen, welche in der tektonisch aktiven Region süd-zentral Chiles als Anzeiger periodisch auftretender Erdbeben und somit als Archiv lokaler Seismizität gewertet werden. Für die letzten 140 000 Jahre zeigen die Daten deutliche Schwankungen der Turbiditfrequenzen: Während in Glazialzeiten in etwa ein Ereignis alle 200 Jahre zu verzeichnen ist, treten Turbidite in den Interglazialzeiten nur etwa alle 1000 Jahre auf. Die Häufigkeit der Turbidite scheint demnach nicht nur von der lokalen Seismizität, sondern auch von globalen Klima- und Meeresspiegelschwankungen abhängig zu sein. Beide bestimmen die Sedimentmenge, die den Kontinentalschelf und die Schelfkante erreicht, und damit letztendlich die Stabilität des Kontinentalhanges; so führen stabilere Hangverhältnisse in den Interglazialen zu geringeren Turbiditfrequenzen als in den Glazialen. Da die glazialen Turbidithäufigkeiten gut mit der Häufigkeit von historisch dokumentierten Erdebeben übereinstimmen, scheint in Abhängigkeit der größeren Sedimentmenge und der geringeren Hangstabilität nur in den Kaltzeiten die Gesamtzahl aller großen Erbeben durch Turbidite aufgezeichnet zu werden. Neben dem Klima bestimmt auch die lokale Forearc-Tektonik den Sedimenttransport zur Schelfregion. Erhöhte Hebung entlang tektonischer Strukturen kann zu Veränderungen im Gewässernetz führen und so die Sedimentzufuhr zum Pazifik modifizieren oder gar unterbinden. Zwei Beispiele für die tektonische Blockade von Flusssystemen entlang von Störungszonen sind die heutigen Küstenseen Lago Lanalhue und Lago Lleu Lleu. Beide Seen entwickelten sich aus ehemaligen Flusssystemen, die einst zum Pazifik hin entwässerten und vor etwa 8000 Jahren durch lokale tektonische Hebung entlang einer inversen Verwerfung aufgestaut wurden. Sedimentkernanalysen zeigen für beide Seen eine ähnliche Abfolge von zunächst marinem und darüber liegendem lakustrinen Material. Die genaue Datierung des marin-lakustrinen Übergangs und der Vergleich mit globalen Meeresspiegelkurven erlaubt die Berechnung lokaler holozäner Hebungsraten. Für die Schwellen, die beide Seen eindämmen, sind diese Raten deutlich höher (Lanalhue: 8.83 ± 2.7 mm/Jahr; Lleu Lleu: 11.36 ± 1.77 mm/Jahr) als für die Seebecken selbst (Lanalhue: 0.42 ± 0.71 mm/Jahr; Lleu Lleu: 0.49 ± 0.44 mm/Jahr). Die Schwellen scheinen deshalb Anzeiger einer bislang verdeckten Überschiebung zu sein, die Hebung und Verformung in der Region der beiden Seen beeinflusst. Seit ihrem Aufstauen werden in beiden Seen kontinuierlich lakustrine Sedimente abgelagert und so lokale/regionale Umwelt- und Klimaänderungen archiviert. Die Sedimentsequenzen zeigen einen Übergang von ariderem Klima im mittleren Holozän (8000 - 4200 Jahre vor heute) zu humideren Bedingungen im späten Holozän (seit 4200 Jahren). Dieser Trend stimmt mit anderen paläoklimatischen Daten der Umgebung überein, und wird als Zeichen einer Änderung in der Stärke bzw. Breitenlage der südhemisphärischen Westwinde interpretiert. Seit etwa 5000 Jahren sind die Sedimente des Lago Lleu Lleu durch regelmäßig auftretende detritische Lagen gekennzeichnet, die in ihrer Ursache sowohl tektonisch (z.B. durch Erdbeben) als auch klimatisch (z.B. durch Änderungen der El Niño Southern Oscillation) bedingt sein könnten. Seit etwa 2000 Jahren weisen in beiden Seen vermehrte Schwankungen im Terrigeneintrag auch auf kurzfristigere hydrologische Änderungen hin. Ein verminderter Eintrag lässt auf weniger humides Klima zwischen 200 B.C. - 150 A.D., 900 - 1350 A.D., und nach 1850 A.D. (in etwa der römischen, mittelalterlichen und gegenwärtigen Warmzeit) schließen; vermehrter Eintrag zwischen 150 - 900 A.D sowie 1350 - 1850 A.D. (in etwa den ‚Dark-Ages’ und der Kleinen Eiszeit) weist dagegen ein stärker humides Klima hin. Wie die Ergebnisse zeigen, ist die kombinierte Analyse von marinen und lakustrinen Sedimenten ein praktikabler Ansatz, um klimatische und tektonische Prozesse auf verschiedenen Zeitskalen in ein und demselben Archiv zu untersuchen. Die Methode lässt sich weitgehend auch auf andere aktive Kontinentalränder übertragen.

Palaeosurfaces and palaeovalleys are landforms under destruction in the present climate and/or tectonic regime, and thus mainly reflect processes not active today. Uplifted palaeosurfaces exist along the formerly glaciated passive continental margins around the North Atlantic. Large-scale landform development has recently become a matter of interest also for geologists and geophysicists as the result of an increasing awareness that a thorough knowledge of uplift, erosion, deposition and development of landforms along continental margins can only be accomplished by combined studies using independent data from different scientific disciplines. The present study focuses on one of these above data sets; the landform record. Two uplifted areas, southern Norway and central West Greenland, were selected for landform analysis of high resolution digital elevation models, aerial photographs, relation between landforms in basement and cover rocks, offshore seismic lines and X-ray diffraction of clay minerals in saprolites. In southern Norway, analysis of slope angles within the range of pediment slopes was combined with analysis of main valley incision. This resulted in the identification of three main planation surfaces in a stepped sequence formed along the main valleys as a consequence of tectonic uplift events, maybe in the Palaeogene, (in total >1000 m). Two phases of late uplift (~900 m), probably in the Neogene, triggered incision of deep fluvial valleys, later reshaped by glacial erosion (up to 300 m). In central West Greenland palaeosurfaces were analysed in relation to cover rock of different age. An exhumed etch surface, characterized by a typical hilly relief, occurs on Disko and south of Disko Bugt, and are by the presence of cover rocks shown to be sub-Palaeocene in origin. To the north, a post-Eocene erosion surface on Nuussuaq, cuts across basement and basalt and was probably formed close to sea level. Uplift in two phases elevated this surface up to 2000 m above present sea level and broke it in differently tilted tectonic blocks. South of Disko Bugt, a planation surface, of probably the same age as the one on Nuussuaq, cuts the tilted etch surface, and also cuts across different bedrock types. The planation surface rises towards the south and splits in two surfaces, separated in altitude up to 300 m, within two highly elevated areas. The separation into two surfaces indicate two uplift events: A first minor event of a few hundred metres in the uplift centres resulted in incision of the lower planation surface. This event was later followed by a major uplift event amounting to >1000 m. Correlation with the offshore sedimentary record suggests that both uplift events occurred in the Neogene. The erosion pattern calculated from one reconstructed palaeosurface to present topography shows large spatial variations. This is interpreted as an effect of differential bedrock resistance and local variations of glacial erosion (400–1300 m in low areas). The results presented in this thesis demonstrate the usefulness of palaeosurfaces and palaeovalleys as tools for deciphering magnitude of uplift events, establishing relative event chronologies and for calculation of erosion. Moreover integrated studies of palaeolandforms, offshore geology and thermal chronologies, are shown to be invaluable when used to solve the spatial and temporal patterns of uplift, erosion and deposition.

Diese Arbeit beschäftigt sich mit dem zeitlichen Verlauf und den Gründen des Wechsels zwischen zwei magmatischen Regimen während der Hebung der Zentralen Anden. Das ältere vulkanische Regime wird durch miozäne Schildvulkane repräsentiert, die voluminöse Lavaströme hinterließen. Das zweite Regime besteht aus differenzierteren, steilen Stratovulkanen, mit einem weitaus geringeren Eruptionsvolumen.

The Taimyr Peninsula is a key element in the circum-Arctic region and represents thenorthern margin of the Siberian Craton. The Taimyr Peninsula is a late Paleozoic fold andthrust belt and preserves late Paleozoic through Mesozoic siliciclastic sedimentarysuccessions and providing an ideal location to investigate the Paleozoic to Mesozoictectonic evolution associated with the Uralian orogeny, the Siberian Trap magmatism andopening of Amerasia Basin within a circum-Arctic framework. Multiple methods areadopted, including petrography, heavy mineral analysis and detrital zircon U-Pbgeochronology for provenance investigation, apatite fission track dating for revealingthermal history and balanced cross section for understanding the deformation style ofTaimyr.The results of this thesis indicate that the Late Carboniferous to Permian sediments ofsouthern Taimyr were deposited in a pro-foreland basin of the Uralian orogen during theUralian orogeny. In the Triassic, the siliciclastic deposits still show a strong Uraliansignature but the initiation of Siberian Trap-related input begins to be significant. Erosionof the Uralian orogen has reached a deep metamorphic level. By Late Jurassic andCretaceous time, the deposition setting of southern Taimyr is an intracratonic basin.Erosion and input from Uralian sources waned while greater input from SiberianTrap-related rocks of the Taimyr region dominated. The Taimyr Peninsula underwent atleast three cooling and uplifting episodes: 280 Ma, 250 Ma and 220 Ma, corresponding tothe Uralian orogeny, the Siberian Traps and the late Triassic transpression. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 2: In press. Paper 3: Manuscript. Paper 4: Manuscript.</p>

Στην παρούσα εργασία διερευνάται µια νέα φιλοσοφία αντισεισµικού σχεδιασµού θεµελίων, η οποία βασίζεται στην αξιοποίηση της µη - γραµµικής συµπεριφοράς του εδάφους µέσω διαρροής της θεµελίωσης. Για αυτό το σκοπό δηµιουργήθηκαν στο πρόγραµµα SAP2000 µε επιφανειακά πεπερασµένα στοιχεία, προσοµοιώµατα τοιχώµατος - θεµελίου στη βάση των οποίων δόθηκαν χρονοΐστορίες σεισµών µε στόχο τη µελέτη της ανελαστικής απόκρισής τους. Κατά την διάρκεια της παρούσας διατριβής αναπτύχθηκε µία µεθοδολογία αποµείωσης της αντοχής του προσοµοιώµατος και πραγµατοποιήθηκε πλήθος ανελαστικών αναλύσεων. Οι αναλύσεις που πραγµατοποιήθηκαν έχουν παραµετρικό χαρακτήρα και οδηγούν στην εξαγωγή χρήσιµων για την µελέτη της ανελαστικής απόκρισης θεµελίων, διαγραµµάτων και συµπερασµάτων. / --

It is recognised that some proportion of South American large-scale topography has been generated by convection within the Earth's mantle. Yet, spatial and temporal patterns of dynamic topography remain poorly understood. Variation of present-day dynamic topography can be mapped in the oceans by calculating residual depths with respect to the well-known age-depth relationship. Along the margins abutting South America, anomalies with amplitudes of $\pm1$ km and wavelengths of $\sim10^{3}$ km are observed. Onshore, dynamic topography is investigated by analysing a range of disparate datasets. Positive long-wavelength free-air gravity anomalies and slow shear-wave mantle velocities correlate with high plateaux of the Borborema Province and the Central Andean Altiplano. Admittance analyses of these regions are used to gauge dynamic support. Admittance of $ > 20$ mGal km$^{-1}$ at wavelengths $ > $ 500 km suggests partial dynamic support. In this context, inverse modelling of longitudinal river profiles is applied to retrieve a continental-scale uplift history. Erosional parameters are calibrated against an independently derived uplift history of the Borborema Province that reveals uplift in the last 30 Ma. Results suggest that the bulk of South American regional topography grew during Cenozoic times. In the Central Andean Altiplano and Southern Patagonia, most uplift occurred in the last 20 Ma. In both areas, widespread Cenozoic magmatism suggests that youthful uplift might be related to asthenospheric upwelling. Uplift histories are used to predict sediment flux to the Amazon Fan, which reveals that onset of the delta is a direct consequence of intensified Andean uplift. Analysis of the Parna\'iba cratonic basin of northeast Brazil is carried out to evaluate long-term evolution of vertical motions and to understand the mechanisms driving this basin's subsidence. Joint interpretation of a deep seismic reflection profile that traverses the basin and receiver function analyses reveal a 3 km thick basin underlain by three crustal blocks. Moho depths of 38--43 km are observed beneath the Amazon craton west of the basin, whereas depths of 35 km are found underneath the Borborema Province to the east. The Moho is located at 38--42 km depth beneath the basin. Stratigraphic architecture from shallow seismic reflection profiles reveals undisturbed deposition between Palaeozoic and Mesozoic times. Rift-type structures are locally imaged. Subsidence analysis reveals thermally-driven subsidence with thermal time constants of $\sim$ 70--80 Ma. Assessment of crustal thickness variations indicates that minimal extension of up to 80 km, with small stretching factors (up to 1.15), is plausible beneath Parna\'iba. One- and two-dimensional strain rate histories suggest that pre-Silurian rifting followed by thermal subsidence is possible if a minimum of 1 km of syn-rift deposition occurred. Basin-wide erosional unconformities are observed throughout the sedimentary section and correlate with departures from long-term subsidence trends. These steps are interpreted as transient uplift events that led to development of ephemeral landscapes, suggesting that dynamic topography could have played a role in the evolution of this Phanerozoic basin.

Made available in DSpace on 2014-06-11T19:26:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-01-27Bitstream added on 2014-06-13T19:33:38Z : No. of bitstreams: 1 franco_aob_me_rcla.pdf: 2573807 bytes, checksum: 574f9f24f539eb53bda347597a2b1d4d (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A evolução do Arco de Ponta Grossa, na região sudeste brasileira, durante o Meso-Cenozóico, apresenta uma estreita relação com os eventos tectono-magmáticos responsáveis pela abertura do Oceano Atlântico- Sul. A utilização do Método de Datação por Traços de Fissão em apatitas, nessa região, permitiu a identificação de cinco eventos térmicos, responsáveis pela estruturação dessa feição, a partir do Cretáceo. São eles: Evento A - Aquecimento em 130 Ma, relacionado ao evento de ruptura do Gondwana Sul-Ocidental e geração do Oceano Atlântico-Sul; Evento B - Resfriamento em 110 Ma, associado à reativação de antigas zonas de cisalhamento e/ou falhas geradas na ocasião do evento de ruptura do Gondwana Sul-Ocidental; Evento C - Aquecimento em 90 Ma, associado à um soerguimento regional, interpretado como alçamento de isógradas, provavelmente como reflexo do soerguimento do Arco de Ponta Grossa e conseqüente sedimentação correlativa (Grupo Bauru ls, no interior continental, e seqüência inferior da Formação Santos, na Bacia homônima), bem como de intrusões alcalinas; Evento D - Resfriamento em 60 Ma, correlacionado à um evento erosivo, que propiciou a formação de uma extensa superfície de erosão, neste caso a Superfície Sulamericana, amplamente registrada tanto na parte continental como na porção submersa adjacente ao Arco de Ponta Grossa (sob a forma de discordância regional na Bacia de Santos); Evento E - Resfriamento em 30/20 Ma, associado à atuação de ciclos erosivos, instalação de bacias tafrogênicas e, localmente, intrusões alcalinas. / The evolution of Ponta Grossa Arch, in southeastern Brazil, during Mesozoic-Cenozoic, seems to be related to the tectono-thermal events related to South Atlantic opening. The use of Apatite fission Track Method, in this region, allowed the recognition of five thermal events, responsible for the formation of this feature, since Cretaceous, which are: Event A - Heating event in 130 Ma, related to the Southeastern Gondwana break-up and the origin of South Atlantic Ocean; Event B - Cooling event in 110 Ma, associated to the shear zones reactivation and/or faults generated during Gondwana break-up; Event C - Heating event in 90 Ma, associated with a regional uplift, interpreted as uplift isotherms, probably as a reflection of Ponta Grossa Arch uplift and correlated sedimentation (Bauru Group ls, in continent and the inferior sequence of Santos Formation, in Santos Basin), and alkaline intrusions; Event D - Cooling event in 60 Ma, correspondent to an erosional event, that formed an extended erosional surface, in this case, Sulamericana Surface, registered both in continental region and in offshore portion (registered as a regional discordance in Santos Basin); Event E - Cooling in 30/20 Ma, related to erosional cycles, tafrogenic basins origin and, locally, alkaline intrusions.