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Item Metadata only Improving outcomes for oil and gas projects through better use of Front End Loading and decision analysis(OnePetro, 2018) Newman, D.; Begg, S.; Welsh, M.; SPE Asia Pacific Oil and Gas Conference and Exhibition (APOGCE) (23 Oct 2018 - 25 Oct 2018 : Brisbane, Australia)Outcomes for oil and gas projects often fall short of the expectations predicted at project sanction. Appropriate use of Front End Loading (FEL) and Decision Analysis (DA) to achieve high Decision Quality (DQ) should increase the likelihood of achieving better outcomes. However, despite being successful methodologies, research has shown that they are not always applied. The focus of this paper is on how to encourage people to make better use of FEL and DA. Previous results from this research program have shown two key reasons why FEL and DA are not used more: an over-reliance on ‘experience’ and judgment for decision-making, rather than the use of structured processes; and projects being ‘schedule-driven’, i.e. meeting target dates being the primary objective. This paper focuses on insights from a survey conducted both to answer questions raised by this previous research and test the likely uptake of methods designed to encourage more effective use of FEL and DA/DQ. It shows that there is strong agreement that good FEL leads to better project outcomes, and that the FEL benchmark score is a good indicator of readiness for project sanction. However, perhaps competing with the desire to complete FEL, is the view (of around 2/3 of respondents) that it is important to drive the schedule in order to prevent ‘overworking’ – continued activity that adds little value. All respondents agreed that it is essential: that the decision maker clarifies the frame, scope and criteria for the decision; and to have regular discussions between the decision maker and the project team to bring alignment. However, responses indicated that these only occur in practice around half of the time. Similarly, formal assessments of DQ are made in less than half of key project decisions. Several novel solutions are proposed for increasing the likelihood of better project outcomes by improving the uptake and use of FEL and DA/DQ. These include: just-in-time training on FEL and DA/DQ; basing performance incentives on achieving high DQ and good FEL; and, developing a simple pragmatic assessment of FEL that can be used in-house. These suggestions were all supported by a majority of survey respondents.Item Metadata only Simplified front end loading: A route to better project outcomes(OnePetro, 2020) Newman, D.; Begg, S.; Welsh, M.; SPE Asia Pacific Oil and Gas Conference and Exhibition (APOGCE) (17 Nov 2020 - 19 Nov 2020 : virtual online)This paper aims to encourage Front End Loading (FEL) to be used more effectively to increase the likelihood of delivering better project outcomes. It introduces a simple and pragmatic approach to assessing FEL which can be carried out in-house. Previous research has shown that, despite FEL being highly regarded, companies regularly sanction projects with insufficient levels of FEL. This has frequently resulted in projects not achieving the outcomes promised at the Final Investment Decision (FID) in terms of cost, time and production attained. This paper reviews reasons why FEL may not be used very effectively at present and proposes a solution to change this. An alternative method of assessing FEL has been developed which: is decision-based; can be carried out internally; and provides clarity on the factors that drive good FEL. In addition to assessing the status of activities carried out in the phase, the decision-based approach emphasises value-creation by considering key factors that could influence an increase or decrease in Decision Quality and thus the value created by the final outcome. The benchmarking and the decision-based approaches to FEL are very different. FEL benchmarking is external, objective, more bottom up; whereas the decision-based approach is internal, subjective and more top down. The benchmarking approach is more detailed, with a large number of individual activities assessed, and the progress on these aggregated to provide an overall benchmarking score. The decisionbased approach is more of a big picture view. FEL benchmarking is well proven and its use is advocated. The decision-based FEL approach is unproven, but it has benefits that are not available from benchmarking and avoids some of the disadvantages. It encourages consideration to be given to activities that may result in value being created or destroyed; e.g. ensuring there are sufficient and appropriate alternatives during the Select phase, and that the benefits of flexibility are taken into account. A further advantage of the decision-based approach is that working through the FEL tools as a project team leads to a better joint understanding of the project and improves team integration. The two approaches consider FEL from different perspectives and have different benefits. They complement each other, and so the combination of the two approaches is more powerful than either on its own. It is suggested that the two approaches are worked in conjunction with each other to gain the benefits of both methods, provide a better understanding of FEL, and have a stronger basis for decision-making. A new way of assessing FEL has been developed which uses a decision-based approach aimed at increasing the value of project outcomes. Separate tools are provided for the Concept Select and FID phases.Item Metadata only Bias in Science and Communication: a field guide(IOP Press, 2018) Welsh, M.B.Item Metadata only Individual differences, expertise, and outcome bias in medical decision making(Cognitive Science Society, 2019) Liaw, A.; Welsh, M.B.; Copp, H.; Breyer, B.; Annual Conference of the Cognitive Science Society (COGSCI) (24 Jul 2019 - 27 Jul 2019 : Montreal, Canada); Goel, A.K.; Seifert, C.M.; Freska, C.Outcome bias describes the tendency of people to alter their rating of a decision’s quality according to whether the outcome is good or bad – despite equivalencies in available information and decision processes – which has the potential to undermine learning about causal structures and diagnostic information in many fields, including medicine. Herein, a sample of 181 doctors and medical students is shown to display outcome bias in medical and non-medical scenarios – with their susceptibility correlating across the domains, r = 0.38. Analyses showed that rational and intuitive decision styles and a medical risk tolerance measure offered little predictive power. Instead, the strongest drivers of bias susceptibility were the Age and professional Level of participants, with more senior personnel showing less outcome bias. We argue that this could reflect improved learning across a doctor’s career or result from increasing confidence making them less likely to change their initial judgement of decision quality.Item Metadata only Can 1 h of training lead to better project decision-making?(Elsevier, 2020) Newman, D.; Begg, S.; Welsh, M.An experiment was set up to determine whether some short, focused training could influence decision makers to take a more structured and process-based approach to project decision-making. The experiment also investigated the impact on project decision-making of the way a decision is framed by an authority figure, i.e. how a decision is influenced by an authority figure advocating a process-driven, neutral or an opinion/schedule-driven approach. The experiment was set up so that half of the participants watched three 15-min training videos before answering questions on decision-making scenarios for projects, and the other half just answered questions on the decision-making scenarios. 40% of participants (split across those who watched the training videos and those that only answered the decision-making scenario questions) had undergone some prior training on decision making. The results demonstrate that watching the training videos has an impact. The impact is greater when there has been no prior training; however, there is still impact in each case, albeit small for some. This implies that the benefits of 1 h of training prior to project decision-making is more valuable for those with no prior training, but still worthwhile for those with prior training. The results showed that framing by an authority figure has a strong influence on the participants’ responses, in terms of whether a process-based, neutral or opinion/intuition-based response was given.Item Open Access What is the CRT? Intelligence, Personality, Decision Style or Attention?(Cognitive Science Society, 2022) Welsh, M.; Annual Conference of the Cognitive Science Society (COGSCI) (27 Jul 2022 - 30 Jul 2022 : Toronto, Canada); Culbertson, J.; Perfors, A.; Rabagliati, H.; Ramenzoni, V.The well-known CRT is a test designed to measure a person’s ‘cognitive reflection’ and used as a predictor of decision making ability. Within the literature, however there is a growing consensus that it shares the majority of its variance with numerical and other cognitive abilities and thus the question increasingly asked is whether it has predictive power beyond existing measures. That is, is there something unique captured by the CRT? This study examines the CRT in parallel with a wide range of individual differences measures reflecting aspects of intelligence (8 CHC broad ability factors), personality (the Big 5 and 30 facets), other decision styles (5 measures) and attention (12 measures covering six aspects of attention). Results indicate that the CRT is, primarily, a cognitive measure, strongly linked to fluid, crystallized and quantitative ability but may also be capturing some distinct aspects of attention relating to the ability to ignore distractors.Item Metadata only Transferability of calibration training between knowledge domains(Cognitive Science Society, 2019) Babadimas, C.; Boras, C.; Rendoulis, N.; Welsh, M.B.; Begg, S.; Annual Conference of the Cognitive Science Society (COGSCI) (24 Jul 2019 - 27 Jul 2019 : Montreal, Canada); Goel, A.K.; Seifert, C.M.; Freska, C.Many industry professionals are poorly calibrated, overestimating their ability to make accurate forecasts. Previous research has demonstrated that an individual’s calibration in a specific domain can be improved through calibration training in that domain; however devising a training program for each specific domain within a field is laborious. A more efficient method would be if individuals from different disciplines could undertake the same general training and transfer the skills learnt to their respective, specific domains. This study investigated whether calibration training in a general domain was transferable to the specific domain of petroleum engineering. The results showed that, whilst the feedback training was effective within the general domain, there was only limited transfer to the specific domain. This is argued to be due to recognition failure, where the participants failed to recognise that the skill learnt through training in the general domain could be transferred to the specific domain.Item Metadata only Lithostratigraphy and Chemostratigraphy of salt diapir sedimentary inclusions: unraveling Ediacaran salt tectonics in the Flinders Ranges, South Australia(Department for Energy and Mining, 2021) Kernen, R.; Lehrmann, A.; Poe, P.Item Open Access Does anything predict anchoring bias?(Cognitive Science Society, 2021) Welsh, M.; Annual Meeting of the Cognitive Science Society (CogSci) (26 Jul 2021 - 29 Jul 2021 : virtual online); Laughlin, P.Anchoring – the tendency for recently seen numbers to affect estimates – is a robust bias affecting expert and novice judgements across many fields. An anchoring task, in which people (N=301) estimated the number of circles in 10 stimulus figures after comparison to an anchoring value, was conducted within a larger study including numerous intelligence, personality, decision style and attention measures. Individual anchoring susceptibility was calculated and compared to potential predictor variables. Two of eight broad ability measures (from Catell-Horn-Carroll intelligence theory) correlated weakly but significantly with anchoring (Gq = 0.16, Gf = 0.12). No decision style or attention measures correlated significantly with anchoring, nor did the Big 5 personality traits, directly. Indirectly, however, as the anchoring task continued and fatigue increased, people relied more on anchors and higher neuroticism may have increased this tendency. Overall, results suggest our ability to predict anchoring is poor and implications of this are discussed.Item Open Access Overconfident in hindsight: memory, hindsight bias and overconfidence(Cognitive Science Society, 2020) Welsh, M.; Annual Meeting of the Cognitive Science Society (CogSci) (29 Jul 2020 - 1 Aug 2020 : virtual online); Denison, S.; Mack, M.; Xu, Y.; Armstrong, B.C.Overconfidence and Hindsight Bias are two well-known cognitive biases. Herein, it is argued these biases may be related to one another and human memory limitations; specifically, that memory limitations result in hindsight bias, causing people to recall being right more often than they actually were, which leads to overconfidence as people apply this misremembered confidence to future events. Analyses comparing three types of overconfidence (overestimation, overplacement and overprecision) and hindsight bias confirm strong, positive correlations between the different types of overconfidence – from 0.488 up to .807 and moderate correlations (.331 to .398) between all of these and hindsight bias. Comparisons between bias scores and five broad cognitive abilities (from the CHC model) suggests hindsight bias is more pronounced in people with worse memories and generally, lower cognitive ability. Overall, results are argued to support the proposed links between memory, hindsight bias and overconfidence and future directions are suggested.Item Open Access May I have your attention? Testing a subjective attention scale(Cognitive Science Society, 2020) Welsh, M.; Annual Meeting of the Cognitive Science Society (CogSci) (29 Jul 2020 - 1 Aug 2020 : virtual online)The concept of ‘attention’ – our ability to focus on particular parts of the world - is a seemingly simple one. Research, however, often driven by clinicians need to diagnose attentional deficits after brain injuries, has demonstrated its complexity. This has resulted in significant testing being required to assess the full range of attentional abilities. Herein, we designed a Subjective Attention Scale, consisting of 15 Likert-scale questions based on five types of attention identified by Sohlberg and Mateer (1989). Preliminary data suggested the scale had good psychometric properties (Cronback’s α > 0.8) and an interpretable factor structure (4 factors; 49% of variance). However, it showed almost no significant correlations with measures from six laboratory tests of attention. Instead, analyses suggest peoples’ subjective beliefs regarding their attentional abilities map more closely onto the Conscientiousness personality trait than those traits identified from clinical work.Item Metadata only Analytical model for fines migration due to mineral dissolution during CO₂ injection(Elsevier BV, 2022) Wang, Y.; Bedrikovetsky, P.; Yin, H.; Othman, F.; Zeinijahromi, A.; Le-Hussain, F.Recent laboratory studies have proposed carbonate mineral dissolution as a main mechanism for fines migration during CO2 injection. However, existing mathematical models of fines migration ignore mineral dissolution as a mechanism for fines generation. To address this gap, we derive a basic system of governing equations that incorporate fines migration induced by mineral dissolution. An analytical solution is derived for four zones defined based on normalized porosity and carbonate mineral concentration profiles. These profiles are then used to derive the suspended and retained fines concentrations. The analytical solution is found to be in close agreement with the numerical solution of the basic system of governing equations. To validate our model, we perform injection experiments on four Berea sandstone cores. Each core receives injection of CO2-saturated water of designated salinity 0, 0.17, 0.51, or 1.03 M NaCl. The results suggest that two competitive phenomena occur due to carbonate mineral dissolution during CO2- saturated water injection, i) increased porosity that is responsible for the increase in permeability and ii) fines migration that results in permeability reduction. Dissolution of intergranular cement results in fines dislodge, some of which subsequently cause pore blockage and permeability reduction. For 0, 0.17, and 0.51 M salinity, mineral dissolution is found to be dominant, yielding a net increase in rock permeability due to increased porosity. For 1.03 M salinity, higher dissolution rates are found to cause significantly more fines, yielding a net decrease in rock permeability. The comparison of experimental and modelling data shows high agreement with the experimental data, which validates the proposed model.Item Open Access Calcite Twin Formation, Measurement and Use as Stress-Strain Indicators: A Review of Progress over the Last Decade(MDPI AG, 2021) Lacombe, O.; Parlangeau, C.; Beaudoin, N.E.; Amrouch, K.Mechanical twins are common microstructures in deformed calcite. Calcite twins have been used for a long time as indicators of stress/strain orientations and magnitudes. Developments during the last decade point toward significant improvements of existing techniques as well as new applications of calcite twin analysis in tectonic studies. This review summarises the recent progress in the understanding of twin formation, including nucleation and growth of twins, and discusses the concept of CRSS and its dependence on several factors such as strain, temperature and grain size. Classical and recent calcite twin measurement techniques are also presented and their pros and cons are discussed. The newly proposed inversion techniques allowing for the use of calcite twins as indicators of orientations and/or magnitudes of stress and strain are summarized. Benefits for tectonic studies are illustrated through the presentation of several applications, from the scale of the individual tectonic structure to the continental scale. The classical use of calcite twin morphology (e.g., thickness) as a straightforward geothermometer is critically discussed in the light of recent observations that thick twins do not always reflect deformation temperature above 170–200 °C. This review also presents how the age of twinning events in natural rocks can be constrained while individual twins cannot be dated yet. Finally, the review addresses the recent technical and conceptual progress in calcite twinning paleopiezometry, together with the promising combination of this paleopiezometer with mechanical analysis of fractures or stylolite roughness.Item Metadata only Inherited morphobathymetric controls over contourite drift deposition: a case study from the late Cenozoic Mentelle Basin, Australia(Society of Exploration Geophysicists, 2021) Tagliaro, G.; Wainman, C.C.; Fulthorpe, C.S.Deep-sea sedimentary deposits are important archives of the geologic past that preserve the records of past environmental changes in earth’s ocean. The detailed analysis of deep-sea sedimentary archives, in particular of contourite drifts, can help elucidate past changes in ocean circulation and the stratigraphic evolution of continental margins. However, the bathymetric profile of an oceanic basin can shape and modify the architecture of contourite drifts via the interaction between down-slope and along-slope processes. The identification of local bathymetric influence on depositional architectures is therefore important to help decipher local versus regional influences on deep-sea sedimentary signatures. Seismic data from Mentelle Basin in the southeast Indian Ocean integrated with deep-sea core data reveal a calcareous-siliciclastic mixed contourite-turbidite system developed during the late Cenozoic, starting in the middle Miocene. Current winnowing led to the formation of regional hiatuses, ferromanganese crusts, and siliciclastic lag deposits. The main locus of sediment deposition occurred on the shallower parts of the basin, whereas sediment preservation remained low in the deeper areas. Seismic analysis shows that inherited topography influenced the architecture of contourite deposits within the basin, with elongate-mounded and sheeted drifts forming preferentially at shallower depths on the continental slope and the Naturaliste Plateau, while channel incision occurred in the deepest parts of the basin. These results suggest that the intensification of current transport occurred preferentially within the deeper and spatially constrained parts of the basin, whereas current deflection around the slope and plateau enhanced drift deposition and preservation at shallower depths. Therefore, the basin topography at the time of deposition controlled the distribution of deep-sea deposits and drift morphologies within the mixed contourite-turbidite system in the Mentelle Basin.Item Metadata only The Cooper-Eromanga petroleum province, Australia(Taylor & Francis, 2022) Kulikowski, D.; Amrouch, K.; Pokalai, K.; Mackie, S.I.; Gray, M.E.; Burgin, H.B.This review focuses on integrating old literature with present-day models to provide a modern summary of Australia’s largest onshore hydrocarbon province, the Cooper–Eromanga Basin, with a focus on structural geology and geophysics. A rapid rise in cutting-edge research has been facilitated by hydrocarbon companies transitioning to technically more challenging plays and feasibility studies assessing the carbon capture and storage potential of the basin. The purpose of this review is to provide researchers and new and existing operating companies with an integrated summary of recent research and the fundamentals of the structurally complex basin with the aim of ensuring that the hydrocarbon potential can be effectively explored and appropriately developed, and that the carbon capture and storage potential of the basin is appropriately evaluated. A modern tectonostratigraphic evolution model is presented alongside the stress regime, orientation and magnitude of the six events that have affected the province (N–S Carboniferous Alice Springs Orogeny; SE–NW mid-Permian event; NE–SW late Permian Daralingie event; E–W Triassic Hunter–Bowen Event; E–W Late Cretaceous event; N–S Paleogene event). Integration of complete paleo-stress tensors with geomechanical models has constrained the dynamic reactivation (shear and tensile) of faults through time and space to find that since the critical time (90 Ma), N–S- and E–W-striking high-angle (50–70°) faults were most likely facilitating hydrocarbon migration. These form the major topics of the review as they can significantly impact exploration and development success and effective carbon capture and storage. In addition, the four-dimensional distribution of natural fractures away from the wellbore, seismic time-to-depth conversion methods and accuracies, petroleum systems elements and processes, current and future exploration programs, common hydraulic fracturing and well surveillance programs, and recommendations for future research are also discussed. The methodologies, cutting-edge research and novel approaches presented here form a framework that can be applied to other hydrocarbon provinces around the world, while also providing a knowledge platform for this highly prospective hydrocarbon and potential carbon storage province.Item Metadata only A fractal approach for surface roughness analysis of laboratory hydraulic fracture(Elsevier, 2021) Movassagh, A.; Haghighi, M.; Zhang, X.; Kasperczyk, D.; Sayyafzadeh, M.Hydraulic fracturing treatment in rocks creates surfaces that are not smooth but rough in general. Accurate characterization of surface roughness is necessary to relate fracture deformation to fluid flow. In this study, we analyze the surface of an experimentally generated hydraulic fracture using a practical fractal approach which is capable of modeling applications. The hydraulic fracturing test is conducted using a nearly homogeneous siltstone cube in a true triaxial cell, and a fracture is created showing a perfectly radial pattern. To evaluate roughness, each surface profile is decomposed into large-scale fracture waviness and localized surface roughness considering various length scales. Despite the waviness, estimated roughness amplitudes follow a power-law relation up to a length-scale, showing a fractal nature. Unlike ideal brittle materials with an exponent of 0.5, the roughness exponent is found to vary in a narrow range of 0.1 but exceeds 0.5. The fractal dimension (box dimension) of the hydraulic fracture surface is estimated to be 1.4 showing a good match with roughness exponents. An increase in roughness exponent may indicate an increasing difficulty in fracture propagation and fluid and proppant transport along the fracture. As such, the topology of a hydraulic fracture surface is essential to hydraulic fracture growth to assess fracturing performance.Item Metadata only Layer parallel stretching? Characterising magnetic and pore-fabric styles at a rifted continental margin: New insights from the Otway Ranges, Australia(Elsevier, 2021) Burgin, H.B.; Robion, P.; Amrouch, K.This study presents the first analysis of the anisotropy of magnetic susceptibility (AMS) coupled with anisotropy of P-wave velocity (APV) in sedimentary rocks from a passive continental margin. In the Otway Ranges, Australia, the Lower Cretaceous sediments deposited during a period of subsidence and structural quiescence display triaxial-magnetic fabrics typical of extensional deformation. The extensional interpretation from AMS is also supported by the orientation of the pore fabric measured using APV. The inferred extensional azimuths from both AMS and APV analyses are in good agreement with axes for renewed Late Cretaceous rifting and the continental break up of Gondwana, a period of structural evolution characterised by abnormally-high levels of paleostress in the Otway Basin. Predicated on this we introduce the concept of layer parallel stretching (LPSt), a process that describes pore-scale structuring representative of the first phase of extensional deformation during periods of intense tectonic extension, in this case the LPSt was oriented NE-SW. These extensional structural fabrics in the Otway Basin were preserved during NE-SW oriented basin inversion, a process that involved reactivation of the local detachment, the partitioning of strain, and low levels of coupling between the basement and the cover. The results highlight the applicability of AMS and APV for characterising rock anisotropy in sedimentary basins at continental margins and have distinct outcomes with respect to the structural framework of the study area in the Otway Ranges.Item Metadata only Effect of temperature on mineral reactions and fines migration during low-salinity water injection into Berea sandstone(Elsevier, 2021) Wang, Y.; Yu, M.; Bo, Z.; Bedrikovetsky, P.; Le-Hussain, F.Recent experiments on sandstone rocks found more fines migration at higher temperature. They attributed this to temperature-dependent zeta potential. However, temperature also affects mineral reactions. The present study investigates the effect of temperature on both fines migration and mineral reactions. Two sets of single-phase injection experiments are performed using Berea sandstone sister plugs. In one set of experiments, solutions of NaCl brine are injected at a constant temperature of 25 ◦C, 50 ◦C, or 70 ◦C. In the other set, solutions of CaCl2 brine are injected at a constant temperature of 25 ◦C or 50 ◦C. All plugs are subjected to five sequential injections of the designated brine at salinities 0.684 mol/L, 0.171 mol/L, 0.043 mol/L, 0.0085 mol/L, and 0 mol/L. Permeability at each injection stage is calculated from pressure difference across the core. When NaCl brine is used, the percentage of permeability decrease is found to be 99% at 25 ◦C, 90% at 50 ◦C, and 40% at 70 ◦C. The lower permeability decrease at high temperature is found to be accompanied by a smaller concentration of produced fines. Comparison of scanning electron microscope images taken before and at the end of each experiment shows pore enlargement due to mineral reaction at high temperature, which further explains the lower permeability decrease. Ionic concentrations of Ca2+and Mg2+in the produced water are found to be greater at higher temperature, due to higher reaction rate. With CaCl2 brine, a 7% permeability decrease is observed at 25 ◦C, whereas a 20% permeability increase is observed at 50 ◦C. The observed fines concentration and increase in Ca2+ion production are found to be lower than with NaCl brine, which is attributed to ion exchange between Na+and Ca2+with NaCl brine. Temperature affects both (1) permeability increase due to pore enlargement caused by mineral reactions, and (2) permeability decrease due to fines migration.Item Metadata only The intracontinental High Atlas belt: geological overview and pending questions(Springer (part of Springer Nature), 2021) Skikra, H.; Amrouch, K.; Soulaimani, A.; Leprêtre, R.; Ouabid, M.; Bodinier, J.-L.The High Atlas intracontinental belt is an inverted rift formed along the Northwest African Craton, between the Central Atlantic Ocean and the Africa-Eurasia plates’ boundaries. Due to its particular location at this triple junction, the Moroccan High Atlas is a good example to investigate the tectonic and geodynamic complexity within continental interiors. The present paper aims to give an overview of the actual understanding of the post-Variscan tectonic and structural history of the High Atlas belt and to shed light on some of the most actively debatable questions relating to the geodynamic context of its uplifts. The High Atlas basin Alpine history started with a period of passive rifting during the Middle-Late Triassic-Early Liassic resulting in a complex rift system actuated by the reactivation of Variscan NNE to ENE-trending structures in the framework of a global NW-SE extension. The Late Triassic rift basins were filled by thick salt-bearing red-beds whose post-rift extensive halokinetics has a considerable impact on the structural architecture of the Western and Central High Atlas. Extensional deformation was renewed in the Central High Atlas at the Late Liassic-Early Bajocian associated with the drowning of Liassic carbonate platform coevally with salt mobilization which led to the initiation of NE to ENE-elongated narrow diapiric ridges. By the Middle Jurassic, a major part of the High Atlas basin was submitted to a widespread post-rift epeiorogenic upward motion that lasted up until the Lower Cretaceous, and to which is associated the occurrence of transitional to moderately alkaline magmatism that was emplaced within the established ridges across basement faults. The driving geodynamic mechanisms and the tectonic setting of this uplift are poorly known but the large extent of the exhumed lands in both margins of the Central Atlantic and the synchronicity between the upward movements and the drastic increase of the Central Atlantic Ocean spreading rate suggests a possible causal link between the Central Atlantic dynamics and the Middle Jurassic-Lower Cretaceous post-rift exhumation. The Late Cretaceous signals the onset of the convergence between Africa and Eurasia and the consequent Alpine orogeny. The effective inversion of the Atlas paleo-rift begun during the Eocene and accentuated during the Neogene in an intra-continental environment. The western segment of range witness a basement-involved thick-skinned faulting and folding style, whereas thin-skinned deformation detached mostly on Upper Triassic-Early Liassic evaporitic layers is focused in external forelands. In the Central High Atlas, the salt-involved Cenozoic deformation triggered the evaporites squeezing and extrusion and the inversion of the pre-structured magmatic cored ridges into compressional anticlines. During the Alpine orogeny, the High Atlas orogen underwent weak crustal shortening with the development of a moderate crustal root that resides over a highly elevated Lithosphere-Asthenosphere Boundary. The most prevailing view predicts the occurrence of a hot mantle anomaly, superimposed to the collisional deformation, beneath the Atlas range that maintains the high topography featuring the High Atlas orography. Although advanced studies have been performed, several questions regarding the kinematic history, the origin of the vertical movements, the role played by the week salt layers during both extensional and compressional deformation stages, and the factors controlling the selective inversion of the paleo-rift normal faults and the deep geometry of the range’s major faults, are still not well resolved and deserve to be deeply re-investigated.Item Metadata only Provenance of Upper Jurassic–Lower Cretaceous strata in the Mentelle Basin, southwestern Australia, reveals a trans-Gondwanan fluvial pathway(Elsevier, 2021) Maritati, A.; Halpin, J.A.; Whittaker, J.M.; Daczko, N.R.; Wainman, C.C.Australia, and East Gondwana more broadly, host extensive Paleozoic–Mesozoic sedimentary basins with thick siliciclastic sequences. These sediments were for the greater part transported by large-scale fluvial systems; however, the spatial and temporal patterns of sediment dispersal remain poorly understood. We investigate the provenance of rift strata in the Mentelle Basin, Western Australia, which were deposited during the Late Jurassic–Early Cretaceous breakup of India from Australia-Antarctica. Monazite U–Pb and zircon U–Pb–Hf isotopic signatures suggest that the Upper Jurassic–Lower Cretaceous syn-rift sediments were supplied predominately by a transcontinental river system draining sediments from interior regions of East Antarctica to the northern Gondwanan passive margin. This fluvial system was focused within the developing rift between India and Australia-Antarctica. Provenance of the transgressive marine post-breakup strata reflects a transition to a proximal sediment source and marks the end of the transcontinental fluvial system after the final breakup of India from Australia-Antarctica in the Valanginian (~136 Ma). Statistical comparison of detrital zircon spectra of Mentelle Basin syn-rift strata with other Australian Paleozoic–Mesozoic rift strata located along our proposed transport route suggests that the transcontinental fluvial pathway was active since the Late Paleozoic. We infer that this fluvial system was one of the principal modes of siliciclastic sediment delivery to rift and passive margin basins of western Australia.