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As a result of complex extensional tectonics in northeast China and southern portions of Mongolia, some workers have interpreted the Cretaceous Maanshan Uplift and associated Chifeng basins as metamorphic core complex. Previous work has relied solely upon kinematic indicators to determine the structural origin of these basins. To fully understand the creation of these basins, the sedimentiological record was analyzed in this study. The early Cretaceous sedimentary fill of these basins was analyzed to determine if it is synextensional in nature, and if so what manner of extension was in progress during that deposition. The Chifeng basins are filled with four distinct facies associations and are floored by Late Jurassic and Early Cretaceous volcanics of intermediate and felsic composition. The facies associations observed are interpreted as lacustrine/fluvial deposits, alluvial fan conglomerates, distal fan deposits with fluvial deposits, and hanging wall derived fluvial deposits. These facies are composed of sediment shed from the footwall and hanging wall of the master faults and volcanic deposits. Paleocurrent indicators, primarily in the form of imbrication, along with clast count data show provenance directly off the structure separating the two basins and from the eastern margin of the southeast basin. The distribution of facies, as well as paleocurrent data, provenance data, and structural geometry, implies that these basins are of half-graben origin and that no sedimentological evidence exists of an Early Cretaceous metamorphic core complex near Chifeng.

O presente trabalho aborda o estudo do argilomineral caulinita. Este, ocorre geralmente como produto de alteração in situ da rocha, sendo definido como caulinita autigênica, ou também pode ocorrer dentro dos processos diagenético (eodiagênese ou telodiagênese). Nos depósitos do Gráben Arroio Moirão ocorre a presença do argilomineral caulinita em todos os perfis levantados, desde a base até o topo. A caulinita encontrada mostra diferente estágios de formação. No primeiro estágio os grãos detríticos são substituídos por uma caulinita com lamelas em estágios iniciais, finas e anédricas. No segundo estágio ocorrem lamelas um pouco mais espessas, com arestas melhor definidas caracterizando uma caulinita subédrica. O terceiro estágio apresenta lamelas bem definidas, mais espessas em relação as iniciais, pseudohexagonais, expondo estrutura em booklets compondo uma caulinita euédrica. Entende-se que devido aos contatos pontuais observados nos grãos detríticos, as rochas do Gráben Arroio Moirão sofreram soterramento não muito profundo configurando uma compactação leve. Provavelmente estes sedimentos se enquadram dentro do processo de eodiagênese, no qual, a temperatura e profundidade caracterizam-se por serem amenos (≤ 70ºC; ≤ 2km). Durante o soerguimento destes pacotes dentro do processo de telodiagênese, as camadas foram expostas a condições intempéricas favoráveis a formação da caulinita. São elas a ação do clima principalmente pela infiltração de água meteórica que utiliza-se do sistema de permeabilidade e porosidade da rocha, bem como falhas e fraturas presentes. Portanto, o argilomineral encontra condições propícias a sua formação, no qual, ocorre substituindo grãos detríticos como feldspatos, micas, fragmentos argilosos, gerando desta forma um processo de caulinização generalizada no Gráben Arroio Moirão. / The survey herein approaches the clay mineral kaolinite study. Either this mineral occurs as a product of a rock alteration in situ, defined as authigenic kaolinite, or it can be developed inside diagenetic processes (eodiagenesis or telodiagenesis). In the Arroio Moirão Graben, the presence of the clay mineral kaolinite is evident in every profile, from the bottom to the top. The kaolinite observed shows different stages of formation. On the first stage, detrital grains are replaced by a kaolinite displaying fine, anedric and incipient lamellae. On the second stage, lamellae are a little bit thicker, presenting better definition to the edges characterizing subedric kaolinite. On the third stage, lamellae are pseudohexagonal, thicker, well ordered and expose booklets structure, forming euhedral kaolinite. Due to the point contacts observed on detrital grains, rocks from Arroio Moirão Graben suffered a not so deep burial, as a result, a slight packing. Probably these sediments are part of eodiagenesis process, where, temperature and depth are mild (≤ 70ºC; ≤ 2km). During the uplift of these rocks under telodiagenesis process, layers were exposed to weathering conditions favorable to kaolinite formation, like rainwater infiltration through permeability and porosity rock system, as well as, faults and joints existent. Therefore, this clay mineral is under favorable conditions to its formation, where kaolinite substitutes detrital grains like feldspars, micas, clay fragments, promoting a widespread kaolinization to Arroio Moirão Graben.

Gediz Graben is a continental extensional basin filled with Neogene sediments. Its margins are controlled by active ~E&amp / #8211 / W-trending fault systems with major system, in terms of total offset and duration of activity, located along the southern margin. The graben evolved as a half graben by the activity of the southern margin during the entire Miocene. Then, the northern margin-bounding structure initiated by Plio&amp / #8211 / Quaternary to form the current configuration of the graben with an inherited asymmetry. The southern margin-bounding fault system forms a graben-facing step-like pattern from the horst block (~2000 m) down to the graben floor (~200 m). The faults become younger towards the graben and the structural maturity decreases in the same direction. Fault plane data suggest ~N&amp / #8211 / S-oriented regional crustal extension through the entire graben history with no evidence of temporal change in the regional extension direction. Minor spatial variations are attributed to poorly defined s3-axis or local stress field anomalies caused by fault interactions. Evolution of the Gediz Graben is a dynamic process as indicated by pronounced changes in the geometry and lateral extend of the southern margin-bounding structures along strike and dip directions. This also influenced the lithofacies, depositional pattern and thickness of the graben fill units. The western Anatolian extension is episodic with earlier (Miocene) and later (Plio&amp / #8211 / Quaternary) phases of extension and intervening short phase of contraction (Late Miocene&amp / #8211 / Early Pliocene). Despite of this fact, evidence for the short-term intervening contractional phase throughout the Gediz Graben is scarce and there is local observation of folds and thrust/reverse faults affecting the AlaSehir formation. These structures suggest that the short-term phase of contraction might have existed but most probably been absorbed by the high rates of extension. This data may further imply that graben evolution from half-graben phase (Miocene configuration) to full graben phase (present day configuration) might be a discontinuous process accompanied by a short-time break in-between.

As indicated by drilling and geophysical data, the Mississippi Valley Graben, the Rough Creek Graben, together with the Rome Trough of eastern Kentucky and West Virginia, are fault-bounded graben structures filled with as much as 27,000 feet of Early to Middle Cambrian sediments. Detailed regional mapping of Cambrian and younger strata within and surrounding these structures indicates that they formed contemporaneously. The proximity of these structures suggests they developed within the same regional stress fields and tectonic environments. These three structures are mechanically and kinematically connected, and formed part of a single continent-scale rift system produced during the breakup of Rodinia and the separation of Laurentia from Amazonia. Data including stratigraphic tops from 1,764 wells, interpretations of 106 seismic profiles, aeromagnetic and gravity survey analysis, and mapped surface geology and structures were used within this project. Seven stratigraphic packages resolvable in both geophysical well logs and reflection seismic profiles were mapped in the subsurface across parts of Kentucky, Ohio, Indiana, Illinois, Missouri, and Tennessee. These stratigraphic units were then analyzed through structure maps, isopachous maps, and across 12 regional well-based cross sections. Detailed analysis of thickness patterns of seven major stratigraphic packages was used to identify the locations and timing of major fault movements within the study area. The regional patterns of fault movements through time were used to investigate how the structures evolved in response to the tectonic episodes in southeastern Laurentia during the Cambrian through Devonian Periods. Active rifting of the Precambrian crystalline bedrock began by the Early Cambrian, and resulted in a thick deposit of Reelfoot Arkose and Eau Claire Formation within the Mississippi Valley and Rough Creek Grabens, and the Rome Formation and Conasauga Group within the Rome Trough. Major tectonic extension ended by the Late Cambrian, prior to the deposition of the Knox Supergroup. Counter-clockwise rotation of the regional sigma-1 stress field between the Middle Ordovician and Early Mississippian (Taconic through Acadian Orogenies) resulted in the reactivation of varying sets of preexisting faults through time. The locations, orientations, and timing of these active faults relate to the deep architecture of the rift system.

O presente trabalho aborda o estudo do argilomineral caulinita. Este, ocorre geralmente como produto de alteração in situ da rocha, sendo definido como caulinita autigênica, ou também pode ocorrer dentro dos processos diagenético (eodiagênese ou telodiagênese). Nos depósitos do Gráben Arroio Moirão ocorre a presença do argilomineral caulinita em todos os perfis levantados, desde a base até o topo. A caulinita encontrada mostra diferente estágios de formação. No primeiro estágio os grãos detríticos são substituídos por uma caulinita com lamelas em estágios iniciais, finas e anédricas. No segundo estágio ocorrem lamelas um pouco mais espessas, com arestas melhor definidas caracterizando uma caulinita subédrica. O terceiro estágio apresenta lamelas bem definidas, mais espessas em relação as iniciais, pseudohexagonais, expondo estrutura em booklets compondo uma caulinita euédrica. Entende-se que devido aos contatos pontuais observados nos grãos detríticos, as rochas do Gráben Arroio Moirão sofreram soterramento não muito profundo configurando uma compactação leve. Provavelmente estes sedimentos se enquadram dentro do processo de eodiagênese, no qual, a temperatura e profundidade caracterizam-se por serem amenos (≤ 70ºC; ≤ 2km). Durante o soerguimento destes pacotes dentro do processo de telodiagênese, as camadas foram expostas a condições intempéricas favoráveis a formação da caulinita. São elas a ação do clima principalmente pela infiltração de água meteórica que utiliza-se do sistema de permeabilidade e porosidade da rocha, bem como falhas e fraturas presentes. Portanto, o argilomineral encontra condições propícias a sua formação, no qual, ocorre substituindo grãos detríticos como feldspatos, micas, fragmentos argilosos, gerando desta forma um processo de caulinização generalizada no Gráben Arroio Moirão. / The survey herein approaches the clay mineral kaolinite study. Either this mineral occurs as a product of a rock alteration in situ, defined as authigenic kaolinite, or it can be developed inside diagenetic processes (eodiagenesis or telodiagenesis). In the Arroio Moirão Graben, the presence of the clay mineral kaolinite is evident in every profile, from the bottom to the top. The kaolinite observed shows different stages of formation. On the first stage, detrital grains are replaced by a kaolinite displaying fine, anedric and incipient lamellae. On the second stage, lamellae are a little bit thicker, presenting better definition to the edges characterizing subedric kaolinite. On the third stage, lamellae are pseudohexagonal, thicker, well ordered and expose booklets structure, forming euhedral kaolinite. Due to the point contacts observed on detrital grains, rocks from Arroio Moirão Graben suffered a not so deep burial, as a result, a slight packing. Probably these sediments are part of eodiagenesis process, where, temperature and depth are mild (≤ 70ºC; ≤ 2km). During the uplift of these rocks under telodiagenesis process, layers were exposed to weathering conditions favorable to kaolinite formation, like rainwater infiltration through permeability and porosity rock system, as well as, faults and joints existent. Therefore, this clay mineral is under favorable conditions to its formation, where kaolinite substitutes detrital grains like feldspars, micas, clay fragments, promoting a widespread kaolinization to Arroio Moirão Graben.

O presente trabalho aborda o estudo do argilomineral caulinita. Este, ocorre geralmente como produto de alteração in situ da rocha, sendo definido como caulinita autigênica, ou também pode ocorrer dentro dos processos diagenético (eodiagênese ou telodiagênese). Nos depósitos do Gráben Arroio Moirão ocorre a presença do argilomineral caulinita em todos os perfis levantados, desde a base até o topo. A caulinita encontrada mostra diferente estágios de formação. No primeiro estágio os grãos detríticos são substituídos por uma caulinita com lamelas em estágios iniciais, finas e anédricas. No segundo estágio ocorrem lamelas um pouco mais espessas, com arestas melhor definidas caracterizando uma caulinita subédrica. O terceiro estágio apresenta lamelas bem definidas, mais espessas em relação as iniciais, pseudohexagonais, expondo estrutura em booklets compondo uma caulinita euédrica. Entende-se que devido aos contatos pontuais observados nos grãos detríticos, as rochas do Gráben Arroio Moirão sofreram soterramento não muito profundo configurando uma compactação leve. Provavelmente estes sedimentos se enquadram dentro do processo de eodiagênese, no qual, a temperatura e profundidade caracterizam-se por serem amenos (≤ 70ºC; ≤ 2km). Durante o soerguimento destes pacotes dentro do processo de telodiagênese, as camadas foram expostas a condições intempéricas favoráveis a formação da caulinita. São elas a ação do clima principalmente pela infiltração de água meteórica que utiliza-se do sistema de permeabilidade e porosidade da rocha, bem como falhas e fraturas presentes. Portanto, o argilomineral encontra condições propícias a sua formação, no qual, ocorre substituindo grãos detríticos como feldspatos, micas, fragmentos argilosos, gerando desta forma um processo de caulinização generalizada no Gráben Arroio Moirão. / The survey herein approaches the clay mineral kaolinite study. Either this mineral occurs as a product of a rock alteration in situ, defined as authigenic kaolinite, or it can be developed inside diagenetic processes (eodiagenesis or telodiagenesis). In the Arroio Moirão Graben, the presence of the clay mineral kaolinite is evident in every profile, from the bottom to the top. The kaolinite observed shows different stages of formation. On the first stage, detrital grains are replaced by a kaolinite displaying fine, anedric and incipient lamellae. On the second stage, lamellae are a little bit thicker, presenting better definition to the edges characterizing subedric kaolinite. On the third stage, lamellae are pseudohexagonal, thicker, well ordered and expose booklets structure, forming euhedral kaolinite. Due to the point contacts observed on detrital grains, rocks from Arroio Moirão Graben suffered a not so deep burial, as a result, a slight packing. Probably these sediments are part of eodiagenesis process, where, temperature and depth are mild (≤ 70ºC; ≤ 2km). During the uplift of these rocks under telodiagenesis process, layers were exposed to weathering conditions favorable to kaolinite formation, like rainwater infiltration through permeability and porosity rock system, as well as, faults and joints existent. Therefore, this clay mineral is under favorable conditions to its formation, where kaolinite substitutes detrital grains like feldspars, micas, clay fragments, promoting a widespread kaolinization to Arroio Moirão Graben.

An integrated field, petrographic , structural , and geophysical analysis of the Panther Creek half -graben (PCHG), in east -central Idaho, was undertaken to determine its tectonic origin. Two competing theories as to the origin of the PCHG exist. One suggests that it formed as part of the TransChallis fault system (TCFS) , a system of northeast-trending normal faults, eruptive centers, and graben that formed in Middle Eocene time. The graben of this system are bounded by northeast-striking normal faults, and show evidence of syn-tectonic deposition of basin-filling volcanic strata. The other theory suggests that the PCHG may have evolved as a result of a post-Challis volcanic extension event (Late Eocene to Early Oligocene). Graben of this event are bounded by NNW-striking normal faults, and Challis volcanic strata are uniformly tilted; this evidence suggests post-volcanic basin formation. This study demonstrates that formation of the PCHG was mostly synchronous with volcanism and that there was very little post-volcanic deformation. Other conclusions of this research are 1) Rates of slip on basin-bounding faults were high, and slip was episodic. Slip occurred on both NE and NNWstriking faults, but more occurred on the NE-striking basin-bounding fault. This is consistent with the dominant NE strike of faults within the TCFS. 2) Most of the older volcanic units in the basin dip more steeply to the SE than overlying younger units , this is evidence for synvolcanic deposition . 3) There is significant hanging wall deformation in the form of folds and normal faults, particularly in the northern and southern portions of the basin . 4) Paleocurrents determined from provenance studies and imbricate fabric in exposed conglomerate beds indicate a flow direction largely to the northwest. This paleocurrent flow crosses the strike of the syn-extensional basin-filling units . 5) The composition of the clasts in the post-volcanic basin -fill deposits suggests that the thick volcanic units preserved in the basin never blanketed highlands NE, E, and SE of the basin and that the footwall of the basinbounding fault system was the main source of sediment in the basin. 6) The magnetic and bouguer gravity surveys indicate a sizable intrusion (most likely related to the nearby Casto pluton) beneath the west-central portions of the basin. The intrusion(s) may be responsible for east-plunging folds in the tuff of Castle Rock. 7) Work initiated during this study to determine the 40Ar/39Ar incremental-release mineral ages and the polarity of the tuff of Castle Rock and the tuff of Challis Creek will help determine the relationship between these two units and will precisely date basin development. However, it is clear that the basin was nearly fully formed by the end of Challis volcanism.

Numerous recent studies have demonstrated the importance of syndepositional faulting as an inherent element of steep-rimmed carbonate margins. However, these studies have not emphasized the relationship to older shelf margins, multiphase deformation history, and complexity of fault zone internal structure. In the Guadalupe Mountains, New Mexico, extensive syndepositional deformation parallels the Permian Capitan shelf margin reef and has developed in the absence of regional tectonic forces due to a combination of early carbonate cementation, gravitational instability, differential compaction, and variable progradation to aggradation at pre-existing shelf margins. This study focuses on the geometry, growth history, and internal fill type distribution within the Cave Graben Fault System (CGFS) in Slaughter and Rattlesnake Canyons of the Guadalupian (Capitan) shelf margin with the intent to understand the temporal and spatial evolution of deformation in front of the G24 shelf margin. Stratigraphy, faults and fractures exposed within the CGFS were mapped using high-resolution gigapan photos and GPS, along with RCRL Guadalupe airborne lidar, provides a geospatial database for 3D visualization, quantification, and interpretation. Detailed mapping reveals a high degree of variability in fault geometry, including the presence of vertical and lateral fault relays, antithetic and synthetic splays, and highly variable fault and fracture apertures, suggesting a complex deformational history. Hundreds of early-formed fractures have been mapped within the G24-G25 shelf margin system, but the development of significant faults with appreciable displacement only occurs in front of the G24 margin. Vertical fault displacement varies from 9 to 34 m in the CGFS. Breccias several meters in width fill the main faults and contain entrained sediment and clasts of variable age and composition. Stratal geometries reveal that movement and episodic growth occurred along the faults soon after deposition. Further investigation of the sediment and breccia fills suggests that a significant dissolution event along the fault allowed for the entrainment of much younger, post-Permian sediment. Based on these findings it appears that in Rattlesnake Canyon at least 30-60% of the CGFS vertical displacement occurs in the Permian, whereas up to 40-70% may develop post-Permian, providing a significant advancement in the understanding of timing of fault systems within the Capitan shelf margin. / text

Abstract There has been an increase in land grabbing in the world over the years and the trend seems to be increasing in the same direction. Whereas, the phenomenon is said to be happening across all continents except Antarctica, in this Africa is the primary target. Uganda too has not been spared and the discovery of oil in 2006 added an insult to an injury. Though, the phenomenon has lived with the world for some good time, it continues to happen with less efforts being made to curb it. As a result, a study was carried out to gain a deeper understanding of the drivers of land grabbing in Uganda’s Albertine Graben. It was a desk study and employed an abductive approach though some primary data was also collected to back it up. The political economy approach was employed to understand the different political and economic dynamics involved in land grabbing. The study found out the issue of absentee land lords and the discovery of oil in 2006 as the main reasons that explain the occurrence of the phenomenon something that is different from the many scholars’ view that agricultural reasons are the main cause. Land grabbing was further seen as mainly negative as it leads to loss of economic livelihoods, lack of cooking energy, displacement of people among others. The study learned that massive sensitization of the people about their rights; strict implementation of the existing laws by the government would help to reduce or solve the problem. Key words, Land grabbing, land acquisition, Albertine Graben, Bunyoro, political economy approach.