Os processos de erosão e produção de sedimentos constituem eventos de grande relevância na atualidade, ocorrendo em escala global e ocasionando prejuízos nas esferas ambiental, econômica e social. Diversas pesquisas concentram seus esforços no sentido de entender as variáveis e os condicionantes destes fenômenos, os quais vêm sendo compreendidos por meio da multidisciplinaridade de diversas áreas do conhecimento. Nesse contexto, o presente estudo teve como objetivo realizar um diagnóstico da produção de sedimentos e de seu transporte na bacia hidrográfica do Rio Itaqueri, localizada nos municípios de Itirapina e Brotas - SP, na qual está inserido o Reservatório do Lobo ou do Broa. Dentre os elementos de análise, foi utilizado o simulador hidrossedimentológico SWAT para estimar a produção de sedimentos na bacia, bem como foi realizado o monitoramento da qualidade da água, a quantificação da carga sólida em suspensão e a determinação da granulometria do material de leito em seções de amostragem localizadas nos principais tributários do reservatório. Por meio da simulação, verificou-se que ocorrem na bacia áreas com diferentes comportamentos hidrossedimentológicos, com locais onde a produção anual média de sedimentos chega a 18 t/ha e outras áreas onde esta é próxima de zero. Foi constatado que o Rio Itaqueri contribuiu com 65% do total anual médio de sedimentos que chega ao reservatório, sendo neste rio também observados os maiores valores de carga sólida em suspensão. A parte alta da bacia configurou-se como uma área de maior aporte de sedimentos na rede de drenagem, sendo os reflexos desta dinâmica observados na qualidade da água destes locais, enquanto nas áreas de médio e baixo curso evidenciou-se a predominância de processos deposicionais. Verificou-se que as análises de parâmetros de qualidade da água e de caracterização do sedimento permitiram complementar os resultados obtidos pelo SWAT, fornecendo subsídios para uma melhor compreensão da dinâmica sedimentológica da bacia. / The soil erosion and the sediment yield are considered one of the biggest present environmental problems, a worldwide issue that inflicts environmental, economic and social damages. Many researches have efforts to understand the variables and constraints of these phenomenon, which have been understood through the multidisciplinarity of different areas of knowledge. In this context, this study attempts to obtain a diagnosis of sediment yield and its transport in Itaqueri River basin, in which is inserted the Lobo-Broa Reservoir. The hydrosedimentological model SWAT was used to estimate the sediment yield in the basin, as well was performed the monitoring of water quality, the quantifying of suspended-sediment discharge and the determination of bed material particle size distributions in streams. Through simulation, it was observed that occur in the basin different hydrosedimentological behaviors, where the average annual production of sediments is 18 t/ha, and its null in some places. It was observed that Itaqueri River contributed 65% of total average annual sediment reaching the reservoir, and this river also has the highest values of suspended-sediment discharge. The upper part of the basin was shown as an area of major input of sediment in drainage network, influencing the water quality in these sub-catchments, while middle course and low course of the river revealed the predominance of depositional processes. Water quality parameters and characterization of river bed sediment supplemented the results obtained by SWAT model, supporting a better understanding of hydrosedimentological processes.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O objetivo fundamental deste trabalho à fornecer subsÃdios que possam contribuir na determinaÃÃo da gÃnese dos nÃveis coquinÃides identificados no Membro Romualdo, FormaÃÃo Santana, da Bacia do Araripe. Para tanto, foram desenvolvidas atividades de coleta de amostras em pontos distintos das porÃÃes central e leste da bacia, a fim de se produzir dados petrogrÃficos e sedimentolÃgicos a partir dos quais se pudessem estabelecer inferÃncias e deduÃÃes sobre os constituintes, feiÃÃes e estruturas identificadas nas rochas. TambÃm se levou em consideraÃÃo os principais estudos jà desenvolvidos no tema objetivando a associaÃÃo com dados prÃ-existentes para efeitos de interpretaÃÃo. Identificando as caracterÃsticas das concentraÃÃes de macrofÃsseis para cada amostra, e comparando-as, foi possÃvel se propor uma origem para a formaÃÃo destes materiais a partir da ocorrÃncia de eventos episÃdicos de tempestades, estando os produtos diferenciados de acordo com a maior/menor influÃncia energÃtica do vetor de transporte e interferÃncia de fatores paleogeogrÃficos especÃficos. AtravÃs da anÃlise micropetrogrÃfica se determinou os litotipos, que variam entre packstones a wackstones bioclÃsticos com porÃÃes fortemente desmicritizadas que originam grainstones. De modo geral, podem ser interpretados tambÃm como biomicritos. Os parÃmetros tafonÃmicos analisados, juntamente ao conteÃdo siliciclÃstico, sugerem aproximaÃÃo com um paleoambiente transicional de dinÃmicas deposicionais complexas e variadas, associadas à ocorrÃncia de eventos de rÃpida sedimentaÃÃo e constantes retrabalhamentos influenciados por episÃdios de tempestades, que contribuÃram no aumento da energia do transporte. Para a interferÃncia marinha neste paleoambiente, considerou-se a influÃncia das Ãguas tetianas durante a transgressÃo iniciada no Aptiano, desempenhando um importante papel na dinÃmica de transporte e deposiÃÃo. Os nÃveis coquinÃides tambÃm sÃo encontrados em outras porÃÃes da Bacia do Araripe (nÃo tÃo somente na porÃÃo Cearense). Assim, uma anÃlise mais detalhada para a origem dessas concentraÃÃes à algo mais complexo a se tratar, ainda mais levando-se em conta um domÃnio paleobiogeogrÃfico ampliado. / The fundamental aim of this research is to provide subsidies that contribute to determinate the genesis of the coquinoid levels identified in the Romualdo Member, Santana Formation, Araripe Basin. Therefore, activities were developed for sampling at different points of the center and eastern border of the basin, to produce petrographic and sedimentological data that could establish inferences and deductions about constituents, features and structures identified on the rocks. It was considered the main related researches already developed, aiming the association with pre-existing data for the interpretations. Identifying the characteristics of macrofossils concentrations for each sample, and comparing them, it was possible to suggest an origin for the formation of these materials from the episodic occurrence of storms, with products characterized according to the major/minor influence of the transport vector and interference from specific paleogeographical factors. The petrographic analysis determined the lithotypes, ranging from bioclastics packstones to bioclastics wackstones, with highly demicritized portions originating grainstones. Overall, may also be interpreted as biomicrites. The taphonomical parameters analyzed, together with the siliciclastic content, suggest a transitional paleoenvironment system and a complex deposition dynamic, associated with the occurrence of rapid sedimentation events and constant reworking espisodes influenced by storms, which contributed to increase the transport energy. It was considered the Tethyan waters influence for the marine interference in this paleoenvironment during the Aptian transgression, playing an important role in the transport and depositional dynamics. The coquinoid levels are also found in others portions of the Araripe Basin (not so only in Cearense portion). Thus, a more detailed analysis for the origin of these concentrations is something more complex to treat, even more considering a magnified paleobiogeografic domain.

Lower Triassic strata in the Wellington Flat and Tully cores reflect a lateral transition from shallow water strata (Wellington Flats core) to strata that indicate deposition on a relatively more distal, storm-dominated ramp (Tully core). The Sinbad Member, along with the upper part of the underlying Black Dragon Member and the lower part of the overlying Torrey Member (Moenkopi Formation), are composed of ten carbonate, siliciclastic and mixed carbonate/siliciclastic facies deposited on a west-facing ramp/shelf that reached maximum flooding during Smithian time. Individual beds and facies display a large degree of lateral homogeneity and regional persistence in the study area. The Wellington Flats core contains the three units characteristic of outcropping Sinbad Limestone: a basal skeletal unit, a middle peloidal unit, and an upper, oolitic dolomite unit. The more offshore Tully core is composed of skeletal grainstone, with fewer shallow-water carbonate and siliciclastic deposits. Discontinuity surfaces (hardgrounds, firmgrounds, and change surfaces) are common and indicate that sedimentation was punctuated by short-lived hiatuses accompanied by cementation, scour, and/or encrustation of the sediment-water interface. The Black Dragon, Sinbad, and lower Torrey Members represent at least one 3rd-order depositional sequence bounded below by the Tr-1 unconformity and above by lowstand deposits in the middle Torrey Member. Amalgamated fluvial channels in the middle of the Black Dragon Member may represent an additional 3rd-order sequence boundary that separates a Greisbachian sequence (lower Black Dragon Member) from the Smithian sequence (upper Black Dragon through lower Torrey members), but this is unsubstantiated by biostratigraphic data at present. Diagenesis is strongly controlled by facies. Diagenetic elements include marine fibrous calcite cements, micritized grains, compaction, dissolution and neomorphism of aragonite grains, meteoric cements, pressure dissolution, and dolomitization. The paragenetic sequence progresses from marine to meteoric to burial. Marine and meteoric cements occlude much of the depositional porosity, which ranges from 0 to 10 % in the sample interval. The best reservoir qualities in core (1.0 md) occur in grainstones and quartz-siltstones. Although its relative thinness precludes it from being a major producer, the Sinbad Limestone Member of the Moenkopi Formation bears potential for modest future oil production.

The Garlock Fault consists of three distinct segments, known as western, central, and eastern, together reaching approximately 260 km from the San Andreas Fault to the southern end of Death Valley. Although published slip rates are available along the western and central Garlock Fault segments, little is currently known of the Garlock Fault earthquake history or slip rate farther east. Using LiDAR and satellite imagery, the central and eastern Garlock Fault segments were analyzed for visibly offset, fault-adjacent, geomorphic surfaces that may potentially be used for estimating slip rate. Qualitative methods of assessing preserved alluvial surface maturity were adapted and used to establish unit age categories. Qualitative comparisons of late Pleistocene-Holocene surfaces reveal that the total offset at sites along the eastern Garlock Fault are less than half that of sites of comparable age along the central Garlock Fault, suggesting a significant reduction in slip rate across the intersection of the Brown Mountain, Owl Lake, and Garlock Faults. Digitally-measured offsets and their age groups were plotted in order to achieve preliminary slip-rate estimates. The resulting plot shows an eastward decrease in late Pleistocene-Holocene slip rate at sites along the central and eastern Garlock Fault segments. The central Garlock Fault slip-rate estimate taken from Slate Range West and Slate Range East sites in Pilot Knob Valley is approximately 4.2 mm/yr, within the error (but on the low side) of previously published rates. The slip-rate estimate from the Quail Mountains site, at the easternmost extent of the central Garlock Fault, is approximately 2.7 mm/yr. The slip-rate estimate from the Avawatz section of the eastern Garlock Fault is approximately 1.0 mm/yr.

Geologic mapping, facies analysis, sedimentary petrography, and detrital zircon analyses of undivided eastern Uinta Mountain Group stratigraphy are presented to better understand the depositional environments and tectonic setting of the Uinta Mountain Group basin. Subdivided units have been modified and correlated from previous work and include the Red Pine Shale, Hades Pass, Crouse Canyon, Outlaw Trail, and Diamond Breaks formations. Three lower-order maximum flooding surfaces associated with the lower Outlaw Trail formation, lower Hades Pass formation, and Red Pine Shale are interpreted. The relative magnitude of each lower-order transgression increases up section along with increasing diversity of palynomorph assemblages found in organic shale intervals. Six facies associations exist within the section and are interpreted as braided fluvial conglomerate, braided fluvial sandstone and conglomerate, braided fluvial sandstone, low-energy braided fluvial sandstone, mudflat, and offshore depositional environments. Both marine and non-marine interpretations are plausible for mudflat and offshore environments; however, previous interpretations of correlative Red Pine Shale exposures suggest a marine environment. The coarsest fluvial environments are restricted to the northern half of the study area and likely coincide with proximity to a tectonically-active northern basin margin. Paleocurrent analysis and the restriction of some subaqueous deposits to the north show northward-dipping depositional slopes, which suggest a tectonic control. Provenance work suggests three general sediment sources existed: an eastern source where ~1.1 Ga and lesser ~1.4 Ga detritus dominate, an east-northeastern source where ~1.8 Ga detritus dominate, and a north-northeastern arkosic source where ~2.7 Ga detritus dominate. Results suggest that during lower-order lowstands, sediments derived from eastern sources dominate. Higher concentrations of ~1.8 Ga and ~2.7 Ga detritus is likely coincident with proximity to the northern basin margin. During lower-order highstands, eastern or northern sources may dominate; northern sources appear more prominently within the Outlaw Trail formation, while eastern sources appear more prominently within the Red Pine Shale. Reasons for this may be linked to the magnitude of the transgressive interval sampled. These relationships, in conjunction with observations of previous studies, suggest the eastern Uinta Mountain Group was deposited in a half-graben style rift, a strike-slip basin, or some combination of the two.

Bunces Pass is an unstructured tide-dominated inlet just north of the main entrance to Tampa Bay, Florida. The inlet has been stable for at least 130 years, as the size, shape, and orientation have remained unchanged. The morphological evolution of the Bunces Pass ebb-tidal delta is influenced by adjacent inlets. Historically, the ebb tidal delta was extremely large, due to the presence of the south channel of Pass-A-Grille Pass. As the tidal prism decreased through the south channel, the sheltering effect produced by the large ebb tidal delta diminished, and large volumes of sand began migrating shoreward. Sediment from the ebb tidal delta accreted along "the Reefs", formed both North Bunces Key and South Bunces Key, and accreted on Mullet Key south of the inlet. Tidal currents at Bunces Pass are primarily ebb-dominant during both summer and winter seasons, though there is flood dominance for several days during neap tides. The ebb dominance is primarily due to the large back-barrier embayment of Tampa Bay, which results in a spring ebb tidal prism of 2.02 x 107 m³. This tidal prism is more than 400 times the corresponding littoral drift. It is primarily responsible for maintaining the inlet's stability, as well as the development of its large ebb-tidal delta. Sediments from the ebb tidal delta at Bunces Pass reflect different degrees of wave versus tidal energy. The strongest tidal currents present throughout the entire ebb tidal delta complex mechanically weather shell gravel in the main channel, producing a shelly, fine quartz sand with relatively high amounts of shell gravel and carbonate sand. This sub-facies is also present on the north channel margin linear bar, due to the interaction of waves, tidal currents, and a southerly littoral drift along this coastal reach. Fine, quartz sand dominates the off shore and swash platform environments. The present situation at Bunces Pass shows a stabilized, tide-dominated inlet with a large, elongate ebb delta that is unlikely to change significantly in the future if present conditions are maintained. The prevalent ebb-dominance suggests that the inlet is hydraulically connected to the adjacent and much larger Egmont Channel inlet system, which also serves Tampa Bay. Strong ebb-tidal currents have kept Bunces Pass in dynamic equilibrium with its surrounding environment. The large ebb tidal prism is responsible for explaining how a tide-dominated inlet is maintained in a microtidal environment.

"February 2001" / Bibliography: p. 335-349. / xxix, 394 p. : ill. (some col.), maps (some col.), plates (col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, National Centre for Petroleum Geology and Geophysics, 2004

<p>This thesis presents a method for detailed landscape presentation. The method incorporates both fieldwork-based comprehensive geomorphological description and digital data handling and thus contributes in filling the gap between traditional geomorphological mapping and modern geomorphological studies performed in Geographic Information Systems (GIS).</p><p>The main part of the thesis relates to development of a new detailed geomorphological mapping system, constructed to be easy to use and yet present a large amount of geomorphological information. The legend of the mapping system has successfully been applied to various types of landscapes, mapped at various scales between 1:5,000 and 1:50,000 without any modifications needed. The information presented in the map is based on simple descriptive criteria and thus the subjectivity is kept low, which enables a broad field of usage. In parallel with the mapping system a GIS-based geomorphological database has been developed. The structure and data presentation of the new mapping system allows for easy transformation of the data to form part of this database. The selected format of the GIS database is the ESRI ArcGIS^®, Personal geodatabase.</p><p>In the development of the geomorphological mapping system four field areas have been mapped in central (Bonäs, Risa and Liden) and northern Sweden (Tarfala). In addition the new legend has been adapted to a field area situated in Vorarlberg, Austria (Upper Gamperdona valley).</p><p>In relation to the Tarfala field area an added issue of the project has been to give insights in the effects of physical and chemical weathering on various rock types to see if this can be detected in materials and landforms. The results from this study point at that resistance towards weathering vary among rocks even though they are of same rock type.</p>

The Granite Wash is comprised of diachronous, Cambrian to Devonian sandstone deposits, which include the Devonian Contact Rapids and Keg River sandstones of which this study will focus. Prolific oil production from the Granite Wash has fueled exploration since the 1950s and as a result substantial core and wireline data is available. Mapping of the Precambrian subcrop suggests that palaeo-highs, known as inselbergs, strongly influenced sedimentation transport, volume, rate, and ultimately preservation after marine transgression. Several distinct surfaces identified from wireline data and cores indicate an overall marine transgression throughout Keg River time. The facies observed represent continental, shallow marine and sabkha environments and a climatic shift from arid to semi-arid to arid. This detailed sedimentological and stratigraphic study provided the depositional framework that allowed for palaeogeographic maps to be constructed.

Cette étude est dédiée à la période charnière que constituent lEifélien et la base du Givétien en Belgique et les régions limitrophes, entre le Dévonien inférieur caractérisé par des dépôts détritiques et linstallation dune plate-forme carbonatée au Givétien. Létude sédimentologique détaillée que nous avons entreprise est le résultat de lintégration de différentes techniques danalyses : sur le terrain (levé et description banc par banc), en lame mince (pétrographie et microfaciès) et sur les échantillons (susceptibilité magnétique et analyses chimiques). Dans le cadre de ce travail, ce sont 14 coupes qui ont été levées, représentant une épaisseur totale de 1650 mètres. Les études de terrain ont permis de mettre en évidence une grande variété de faciès carbonatés, détritiques ou mixtes. Cette variété illustre parfaitement la variabilité latérale qui est la règle au sein de ces niveaux. Les analyses pétrographiques qui ont été menées sur 3352 lames minces, confirment cette diversité et aboutissent à la définition de 71 microfaciès. Ces microfaciès sont répartis sur un modèle de plate-forme et sur 6 modèles de rampe. Ces différents modèles de rampe se distinguent les uns des autres par une influence terrigène plus ou moins marquée, le développement ou non de bioconstructions ou encore la présence ou non de shoals. Les analyses de susceptibilité magnétique on permis de mettre en évidence trois paramètres sédimentologiques principaux linfluençant : lapport détritique (le continent étant la source principale des minéraux porteurs du signal), lagitation (qui peut empêcher le dépôt de ces mêmes minéraux) et la productivité carbonatée (qui peut diluer ces minéraux). Les analyses chimiques quant à elles permettent de clairement dégager 4 pôles parmi les minéraux présents dans les échantillons, chacun ayant sa contribution propre à la valeur de susceptibilité magnétique. Le premier est le contenu en carbonates qui est directement lié à la productivité carbonatée. Outre le quartz détritique, lapport terrigène comporte de son côté deux pôles distincts : lun sous forme dargiles et lautre sous forme de minéraux ferromagnétiques primaires. Le dernier pôle correspond à linfluence de la diagenèse par la dolomitisation et la cristallisation de pyrite, dhématite et éventuellement de magnétite. De par la répartition générale des trois paramètres sédimentologiques cités ci-dessus sur les profils de plate-forme et de rampes, trois types dévolution des courbes de susceptibilité magnétique se dessinent quand on la compare à lévolution des microfaciès. Certaines coupes ne montrent aucun lien entre les deux types de courbes, la susceptibilité magnétique restant relativement constante. Ensuite, un parallélisme peut sobserver entre les deux types de courbes (à une baisse de niveau marin, correspond une hausse de valeurs de susceptibilité magnétique et inversement). Enfin, une opposition peut être observée entre les deux types de courbes (à une baisse de niveau marin, correspond une baisse de valeurs de susceptibilité magnétique et inversement). Une fois identifiés, ces comportements relativement cohérents permettent lutilisation de la susceptibilité magnétique à des fins de corrélation. Lintégration de lensemble des données et interprétations aboutit à la proposition dun canevas de stratigraphie séquentielle. La généralisation de ce canevas à lensemble du bord Sud du Synclinorium de Dinant permet une meilleure compréhension du passage latéral entre la Formation de Couvin et la Formation de Jemelle et de linstallation de la plate-forme carbonatée à la transition Eifélien-Givétien.