Structural Geology

Il presente lavoro è teso a riportare le attività relative alle indagini in foro Down Hole volte al fine di identificare la risposta sismica e le velocità di propagazione delle onde sismiche P ed S nel sottosuolo di P. zza Leonardo sita nel Comune di Napoli. L'attività è ...

The present paper deals with the stratigraphic and biostratigraphic study of the middle-late Miocene thrust-top basin deposits of the San Bartolomeo Flysch, exposed north of Matese mountains and analysed during the geological survey of the sheet Në 405 Campobasso of the new Geological Map of Italy, 1:50.000 scale. The integrated study of calcareous nannofossils and planktonic foraminifera, based on the semi-quantitative distribution range of index species, revealed the presence of age-diagnostic assemblages which are comparable with those of different middle-late Miocene deep-marine sedimentary settings of the Mediterranean Basin. The biostratigraphic dataset suggests an early Serravallian ± early middle Tortonian age. In terms of calcareous nannofossil biostratigraphy, the studied succession falls between the Last Occurrences of Sphenolithus heteromorphus and the First Occurrence of Discoaster bellus gr., corresponding to the MNN6 ± MNN8 zone interval. In terms of planktonic foraminiferal biostratigraphy the studied sediments fall between the Last Occurrence of Globorotalia peripheroronda and the First Regular Occurrence of Neogloboquadrina acostaensis, corresponding to the MM6 p.p. ± MMi10 p.p. zone interval. This study documents the applicability of the recent Mediterranean middle±late Miocene biozonations for the biostratigraphic study of siliciclastic synorogenic sediments, and challenges the most recent studies that dated the San Bartolomeo Flysch to the late Tortonian-early Messinian. Riassunto. Vengono presentati i risultati dello studio stratigrafico e biostratigrafico effettuato sui depositi silicoclastici del Miocene medio-superiore, attribuiti al flysch San Bartolomeo, che affiorano a Nord dei monti del Matese, nel Foglio Në 405 Campobasso della Carta Geologica d'Italia alla scala 1: 50.000. L'analisi semiquantitativa integrata dei foraminiferi planctonici e dei nannofossili calcarei, basata sulla identificazione di significative variazioni di abbondanza delle specie marker, ha permesso di identificare una successione di bioeventi confrontabile con quella riconosciuta in diverse successioni sedimentarie di stessa eta Á e di mare profondo del Bacino Mediterraneo. I sedimenti studiati hanno un'eta Á compresa tra il Serravalliano inferiore e il Tortoniano inferiore-medio. In termini di biostratigrafia a nannofossili calcarei, la successione investigata e Á compresa tra la Last Occurrence di Sphenolithus heteromorphus e la First Occurrence di Discoaster bellus gr., ovvero tra le biozone MNN6 e MNN8. Per quanto riguarda i foraminiferi planctonici, essa ricade tra la Last Occurrence di Globorotalia peripheroronda e la First Regular Occurrence di Neogloboquadrina acostaensis, ossia tra le biozone MM6 p.p. and MMi10 p.p. Questo studio, in accordo con altri studi eseguiti sui flysch s.l. dell'Appennino meridionale, dimostra l'applicabilita Á degli schemi biozonali validi per il Miocene medio e superiore del Bacino del Mediterraneo, sviluppati su successioni non torbiditiche di mare profondo.

This revision program is designed to assist you in revising the critical content and skills covered during TERM 2. The purpose is to prepare you to understand the key concepts and to provide you with an opportunity to establish the required standard and the application of the knowledge necessary to succeed in the GRADE 11 examination. The content in this revision booklet is mostly presented by means of mind maps. This will help you to understand the content easier and also see the relationship between the topics. In most cases, content is integrated with mapwork. This revision booklet should be used in conjunction with the lessons of term 2.

In Ghana the West African Craton is represented by Birimian and Tarkwaian rocks with extensive granitoid bodies. Granitoids from Asamankese area of the Kibi-Winneba volcanic belt, southern Ghana were analysed for major and trace element contents and found to be characterised by highly-fractionated REE, enrichments, in LILE, and depletion in Nb, Ta and Sr. The LILE enrichment relative to strong Nb-Ta depression, indicates that these granitoids were emplaced in an active margin. Based on field relations, geochemical composition and geochronological data, the granitoids from the Kibi-Asamankese area can be divided into three types, namely; the Eburnean biotite granodiorite (2133-2127 Ma) and hornblende granodiorite (2147 Ma), and the Pre-Eburnean gneissic biotite granite (2193 Ma). The geochemical data of the studied rocks plot in the tholeiitic field, whereas on the A/CNK-A/NK diagram, they generally fall within the metaluminous field, with A/CNK values between 0.69 and 0.88. U-Pb dating of zircons in the granitoids yielded ages ranging from 2193 to 2127 Ma, which are among the oldest ages obtained from the granitoid plutons in Ghana. Such high-precision geochronological data indicate that magmatism occurred over a time-span of about 70 Ma. This provides further evidence that the period 2.1-2.2 Ga was one of the important stages of Birimian magmatism that led to the generation of the granitoids. From the above-mentioned ages, it is possible to link the geological activities to crustal processes and establish the cyclic geotectonic evolution in the West African Craton over time as part of an arc-back-arc basin system.

Highlights  Metapyroxenite and amphibolite of the Ketté district attest for magmatic accretion of a Neoproterozoic crust.  Geochemical signatures of metapyroxenite and amphibolite of the Ketté district point to a pre-Neoproterozoic enriched mantle beneath the Central African Orogenic Belt.  Migmatite, heterogeneous granite, tonalite, and granodiorite of the Kette district result from reworking of the mafic juvenile crust and associated sediments.  The structural record of the Ketté district attests for syntectonic partial melting and differentiation of the root of the Central African Orogenic Belt.

We present a strategy for obtaining fault-based maximum observable shaking (MOS) maps, which represent an innovative concept for assessing deterministic seismic ground motion at a regional scale. Our approach uses the fault sources supplied for Italy by the Database of Individual Seismogenic Sources, and particularly by its composite seismogenic sources (CSS), a spatially continuous simplified 3-D representation of a fault system. For each CSS, we consider the associated Typical Fault, i.e., the portion of the corresponding CSS that can generate the maximum credible earthquake. We then compute the high-frequency (1-50 Hz) ground shaking for a rupture model derived from its associated maximum credible earthquake. As the Typical Fault floats within its CSS to occupy all possible positions of the rupture, the high-frequency shaking is updated in the area surrounding the fault, and the maximum from that scenario is extracted and displayed on a map. The final high-frequency MOS map of Italy is then obtained by merging 8,859 individual scenariosimulations, from which the ground shaking parameters have been extracted. To explore the internal consistency of our calculations and validate the results of the procedure we compare our results (1) with predictions based on the Next Generation Attenuation ground-motion equations for an earthquake of M w 7.1, (2) with the predictions of the official Italian seismic hazard map, and (3) with macroseismic intensities included in the DBMI04 Italian database. We then examine the uncertainties and analyse the variability of ground motion for different fault geometries and slip distributions.

In a variety of biological and physical phenomena, temporal fluctuations are found, which are not explainable as consequences of statistically independent random events. If these fluctuations are characterized by a power spectrum density S(f) decaying as f – at low frequencies, this behaviour is called 1/f noise.Counting statistics applied to earthquake activity data leads to three time scales with different characteristics, represented by the exponent/3: at interval lengths less than 1 h, the shocks are randomly distributed as in a Poisson process. For medium time intervals (1 day to 3 months), the exponent 1 +/3 is larger (1.4 for M0=3), but approaches unity for higher threshold magnitudes M0. In longer time ranges the exponent assumes values near 1.55, however, with increasing statistical variation at higher M0, due to lower counts. The temporal sequence is different from white noise; thus, it might be fruitful to apply neural network algorithms, because this method allows predictions in some other cases with similar characteristics.

Augusta e a meus sobrinhos Tutuca, Juju e Bianca ii AGRADECIMENTOS Primeiramente gostaria de agradecer a Deus pela paciência e perseverança designadas a mim e às demais pessoas que, ao longo deste bom tempo, de uma forma ou de outra, comigo conviveram e sem as quais esta dissertação não teria alcançado seus objetivos. Ao Prof. e orientador Carlos Eduardo de Mesquita Barros, pela boa orientação, amizade, paciência, incentivo e dedicação, que se refletiram claramente no êxito deste trabalho. À minha família e minha esposa pelo carinho e amor, e também por tudo aquilo que seus convívios me proporcionaram a aprender, tanto nos momentos felizes como também nas dificuldades. Este trabalho não teria sido possível sem os apoios financeiros provenientes da Universidade Federal do Pará (PROINT) e do CNPq (PRONEX -662103/1998-8; Universal -476623/01-4), a quem somos imensamente gratos. À CAPES pela concessão da bolsa de estudo durante os primeiros dezoito meses de pós-graduação. Ao curso de Pós-Graduação em Geologia e Geoquímica da UFPA pela oportunidade de poder realizar este trabalho. À Companhia Vale do Rio Doce através da equipe de técnicos do Projeto Itacaiúnas, na pessoa dos geólogos Anselmo Viana Soares, Carlos Augusto Medeiro Filho e Otávio Sérgio da Conceição Rosendo. Agradecemos também a sempre cordial colaboração dos técnicos Meira, Cantão e das demais pessoas daquele projeto, o que tornou possível a realização dos trabalhos de campo. Ao amigo Afonso Quaresma pelo companheirismo e alta competência durante os trabalhos de campo, e perícia ao longo das subidas e descidas nas estradas escorregadias de Carajás. Às pessoas que nos auxiliaram com informações valiosas acerca de afloramentos e caminhos durante os trabalhos de campo, assim como pela hospitalidade a nos fornecida. Aos colegas do GPPG, Davis Carvalho, Régis Munhoz e Erimar pela discussão e orientação em diversos assuntos da nossa querida petrologia ígnea, assim como também aos amigos e colegas César Lisboa, Luciene Leão, Lillianne Maia e tantos outros, pelo convívio quase que diário e tudo aquilo de bom que me proporcionaram através de seu carinho e amizade. iii Aos professores e orientandos do Pará-Iso nas pessoas do Prof. Dr. Moacir Macambira pela orientação, mais uma vez, com relação aos cristais de zircão do norte de Carajás; À Sabrina, Roberta Tavares, Ronaldo e Keyla pelo tratamento sempre atencioso de minhas amostras e, finalmente, ao Dr. Marco Antonio Galarza pelo profissionalismo e atenção durante as análises geocronológicas. Aos funcionários da CPRM na pessoa dos geólogos José Maria de Azevedo Carvalho e Orlando José Barros de Araújo pela compreensão e apoio durante os períodos de obtenção dos cristais de zircão e execução de análises geocronológicas, o que demandou alguns deslocamentos até a UFPA.

The hydrocarbon exploration industry has undergone significant evolution in geophysical technologies, such as Full Waveform Inversion (FWI), Amplitude Variation with Offset (AVO), and AI-based modeling, which have fundamentally improved subsurface imaging capabilities. Despite this technological progress, the industry continues to encounter persistent challenges and failures, including expensive deepwater dry holes, which have led to these powerful tools being undervalued and discredited. However, the issue does not seem to lie in the technology but in the human element of its application, specifically through two distinct forms of misuse. First, the "blind application" by non-specialists who ignore underlying physics, and the second, the "overoptimism" of specialists who become obsessed with single models while neglecting contradictory multidisciplinary data. To restore credibility and improve exploration outcomes, the industry must adopt a standardized framework that integrates these advanced tools into a holistic Shared Earth Model rather than treating them as isolated "silver bullets". A proposed workflow necessitates rigorous "physics of the inputs" auditing, the use of Rock Physics Modeling (RPM) to constrain seismic anomalies to physical reality, and a move toward probabilistic inversion approaches validated by AI. Ultimately, this paper also advocates for a multidisciplinary "gating"process involving other disciplines to ensure structural sanity and dynamic consistency, shifting the focus from tool obsession to integrated, data-driven decision-making. Confirmation bias They may inadvertently manipulate parameters or ignore dissenting data that contradicts their initial hypothesis or their model's output.

El presente trabajo presenta una revisión sobre las principales características geológicas, con énfasis en los controles estructurales, que afectan el potencial geoeconómico de los depósitos de talco de la parte occidental del Cinturón San José (Departamento Colonia, Uruguay), identificados como minas Narancio, Dante Ramos y el Sector Zafiro. La geología regional permite concebir dos modelos genéticos complementarios del talco: i) alteración hidrotermal de rocas volcánicas básicas ricas en magnesio o ii) procesos metasomáticos en el contacto entre dolomías y rocas intrusivas ácidas. Finalmente, se sintetiza la historia productiva de la Mina Narancio así como se discute la geometría, el volumen de los cuerpos lentiformes y las calidades de los depósitos de talco del Sector Zafiro a partir de relevamientos de campo con el objetivo de permitir una mejor evaluación del potencial económico.

This paper presents a formal interpretation of gravitational acceleration as an emergent phenomenon arising from a conserved energy influx toward baryonic matter. The central proposal is that the gravitational constant G incorporates the Hubble expansion rate H0. In this interpretation, H0 is not only a parameter describing the recession of galaxies at cosmological scales, but a universal interaction rate active throughout space, including the vacuum regions within stellar and planetary systems.

The data from ASG-EUPOS (Polish Active Geodetic Network) was processed using Bernese 5.0 software and EPN (EUREF Permanent Network) standards and models. In this study, the adapted 3-hour observation window is shifted every hour for obtaining hourly geocentric coordinates in ITRF2005 reference frame. The adjusted network consisted of over 130 stations from Poland and the neighbouring countries, the period covered observations collected from June 2008 through June 2010. These two years of observations allowed for examining short-period oscillations which were found to be closely related to the tidal (dynamic) frequencies. The analysis of the residua from the IERS2003 tidal model was performed using the least squares method with the Eterna software. It confirmed the existence of significant (several millimetres) oscillations in the frequencies corresponding to S1, K1 and K2. The paper describes the idea of data processing and analysis, presents the results of vertical (the Up component) oscillations in main tidal frequency bands, and also includes discussion of possible explanation of the existence of short-period oscillations in the GPS precise solutions and the possibility of propagation of short-period oscillations into long-period spurious changes in the daily (standard) GPS solutions.

The Granada Basin (Central Betic Cordillera), one of the most seismically active areas of the Iberian Peninsula, is currently subjected to NW-SE compression and NE-SW extension. The present day extension is accommodated by normal faults with various orientations but particularly with a NW-SE strike. At the surface, these active NW-SE normal faults are mainly concentrated on the NE part of