Country‐rock structural fabrics as a guide to pluton emplacement depth: An example from the Hodgkinson Province,northeastern Australia

Country‐rock structures adjacent to plutons of the linear, northwest‐southeast‐trending Mt Alto Supersuite, Hodgkinson Province, northeastern Australia, are variably developed from north to south along the belt. S₃ and S₄ cleavages show close temporal relationships with pluton emplacement and are better and more widely developed around plutons in the north, whereas much weaker cleavages of the same generation are only sporadically developed to the south. Cleavage trend lines anastomose around less elongate plutons to the north but are generally truncated by more elongate plutons to the south. It is proposed that a major crustal dislocation, the Alto Fault Zone, comprises a set of subparallel structures that formed prior to granite intrusion and controlled emplacement of some plutons and their final shapes. The north‐south variation in structural relations is interpreted to reflect a corresponding variation in depth of emplacement from north to south, which resulted when post‐emplacement reactivation of the Alto Fault Zone uplifted and sinistrally displaced the northern end of the supersuite relative to the southern end. Reactivation of the fault zone after granite emplacement is supported by the truncation of some plutons.     

Non-Darcian groundwater flow in leaky aquifers

Abstract

A simplified method has been developed for solving leaky aquifer non-Darcian flow hydraulics. The principle of volumetric approach is combined with the confined-aquifer, time-dependent drawdown equation in an observation well. The groundwater flow in the leaky aquifer is assumed to obey a non-Darcian flow law of exponential type. The results are obtained in the form of type-curve expressions from which the necessary bundles of curves are drawn for a set of selective non-Darcian flow aquifer parameters. Although application of the methodology appears as rather limited but it provides a scientific contribution and extension of leaky aquifer theory towards nonlinear flow conditions. The methodology developed herein is applied to some actual field data from the eastern sedimentary basin in the Kingdom of Saudi Arabia.     

Application of linear and nonlinear techniques in river flow forecasting in the Kilombero River basin,Tanzania / Application de techniques linéaires et non-linéaires à la prévision des débits dans le bassin de la Rivière Kilombero,en Tanzanie

Abstract

Modelling of the rainfall–runoff transformation process and routing of river flows in the Kilombero River basin and its five sub-catchments within the Rufiji River basin in Tanzania was undertaken using three system (black-box) models—a simple linear model, a linear perturbation model and a linear varying gain factor model—in their linear transfer function forms. A lumped conceptual model—the soil moisture accounting and routing model—was also applied to the sub-catchments and the basin. The HEC-HMS model, which is a distributed model, was applied only to the entire Kilombero River basin. River discharge, rainfall and potential evaporation data were used as inputs to the appropriate models and it was observed that sometimes the system models performed better than complex hydrological models, especially in large catchments, illustrating the usefulness of using simple black-box models in datascarce situations.     

Ages of sediment-hosted Himalayan Pb–Zn–Cu–Ag polymetallic deposits in the Lanping basin,China: Re–Os geochronology of molybdenite and Sm–Nd dating of calcite

The Lanping basin is a significant Pb–Zn–Cu–Ag mineralization belt of the Sanjiang Tethyan metallogenic province in China. Over 100 thrust-controlled, sediment-hosted, Himalayan base metal deposits have been discovered in this basin, including the largest sandstone-hosted Pb–Zn deposit in the world (Jinding), and several Cu ± Ag ± Co deposits (Baiyangping, Baiyangchang and Jinman). These deposits, with total reserves of over 16.0 Mt Pb + Zn, 0.6 Mt Cu, and 7000 t Ag, are mainly hosted in Meso-Cenozoic mottled clastic rocks, and strictly controlled by two Cenozoic thrust systems developed in the western and eastern segments of the Lanping basin.To define the metallogenic history of the study area, we dated nine calcite samples associated with copper sulfides from the Jinman Cu deposit by the Sm–Nd method and five molybdenite samples from the Liancheng Cu–Mo deposit by the Re–Os method. The calcite Sm–Nd age for the Jinman deposit (58 ± 5 Ma) and the molybdenite Re–Os age for the Liancheng deposit (48 ± 2 Ma), together with previously published chronological data, demonstrate (1) the Cu–Ag mineralization in the western Lanping basin mainly occurred in three episodes (i.e., ∼56–54, 51–48, and 31–29 Ma), corresponding to the main- and late-collisional stages of the Indo–Asian orogeny; and (2) the Pb–Zn–Ag (±Cu) mineralization in the eastern Lanping basin lacked precise and direct dating, however, the apatite fission track ages of several representative deposits (21 ± 4 Ma to 32 ± 5 Ma) may offer some constraints on the mineralization age.     

Prerift and synrift sedimentation during early fault segmentation of a Tertiary carbonate platform, Indonesia

Eocene carbonate deposits of the Barru area, Sulawesi, Indonesia, provide a rare insight into sedimentation prior to and during propagation of normal faults to the surface. Three main successions; late prerift, latest prerift/earliest synrift and synrift, are characterised by distinctive facies associations and sequence development. Shallow water foraminiferal shoals and intervening lower energy depositional environments occurred during the late prerift in areas which latter formed footwall highs and hangingwall depocentres, respectively. During the latest prerift/earliest synrift, shallow water shelves deepened laterally into slope environments in developing hangingwall depocentres. In both these sequences, sections in developing hangingwall areas are thickest, deepen up-section and thin laterally towards growing footwall highs. Active faulting resulted in rapid drowning of hangingwall depocentres and massive reworking of material derived from collapse of the platform margin and adjacent shallow water/emergent footwall highs.Differential subsidence, controlling water depths and accommodation space, types of carbonate producers and active faulting were the main factors affecting depositional environments and facies distributions. Carbonate producers are extremely sensitive indicators of depositional water depth and energy, hence rapid lateral and vertical facies variations in the Barru area provide quantifiable insight into environmental changes prior to and during active faulting.     

廊固凹陷近岸水下扇特征及控制因素

通过对廊固凹陷18口井541 m岩心的系统观察、156口井测井序列的建立、1km×1 km三维地震测网密度的地震相识别,分析了该沉积体系的相带展布特征。该砂砾岩层总体趋势为向上厚度减薄、层数减少,共识别出5期扇体,多呈条带状沿大兴断层断面分布,每期之间发育稳定的暗色泥岩段。该近岸水下扇的形成受3级层序、大兴断层、古构造、古气候、古地形以及物源供给等多种因素的控制。3级层序的发育特点、大兴断层的分段活动以及特殊的物源供给背景因素的匹配对近岸水下扇形成起到决定性作用。2~3期扇体扇中分布范围广,储集条件好,是凹陷下一步开发工作的有利目标。     

Application of an improved semi-Lagrangian procedure to fully-nonlinear simulation of sloshing in non-wall-sided tanks

The semi-Lagrangian procedure is widely used for updating the fully-nonlinear free surface in the time domain. However, this procedure is only available to cases when the body surface is vertical near the waterline. Present study introduces an improved semi-Lagrangian procedure which removes this ‘vertical-wall’ limitation. Coupling with the boundary element method, the improved semi-Lagrangian procedure is applied to the simulation of fully-nonlinear sloshing waves in non-wall-sided tanks. From the result comparison with the open source CFD software OpenFOAM, it is confirmed that this numerical scheme could guarantee a sufficient accuracy. Further series studies on 2D and 3D fully-nonlinear sloshing waves in wedged tanks are performed. Featured phenomena are observed which are distinct from those in wall-sided tanks.     

Diagenetic evolution of the upper Cretaceous limestone and sandstone exhumed reservoirs in the western Basque–Cantabrian Basin,North Spain

The Basque–Cantabrian Basin (NE Spain) has been considered one of the most interesting areas for hydrocarbon exploration in the Iberian Peninsula since the 60th to 70th of last century. This basin is characterized by the presence of numerous outcrops of tar sands closely associated with fractures and Triassic diapirs. The aims of this work is to establish the diagenetic evolution of the Upper Cretaceous reservoir rocks with special emphasis in the emplacement of oil and their impact on reservoir quality. The studied rocks are constituted of carbonates and sandstones that contain massive quantities of bitumen filling vugs and fractures.Petrographic results indicate that the carbonate rocks from Maestu outcrops are bioclastic grainstones and wackestones, whereas the tar sandstones from Atauri and Loza outcrops are dominated by quartzarenites and subordinated subarkoses. The paragenetic sequence of the main diagenetic phases and processes include, pyrite, bladed and drusy calcite cement, calcite overgrowths, silicification of bioclasts and microcrystalline rhombic dolomite cement, and first stage of oil emplacement, blocky calcite cement, coarse crystalline calcite cement, calcitized dolomite, calcite veins, saddle dolomite and stylolites filled by the second phase of oil entrance. Together with the above mentioned diagenetic alterations, the arenites are affected by early kaolinitization of feldspars and the scarce formation of clay rim and epimatrix of illite. All sandstones and dolomitized carbonate rocks show high intercrystalline and intergranular porosity which is full by biodegraded hydrocarbons (solid bitumen). The biodegradation affects alkanes, isoprenoids and partially hopanes and steranes saturated hydrocarbons. Aromatics hydrocarbons, like naphthalenes, phenanthrenes, dibenzothiophenes and triaromatics are also affected by biodegradation. Results indicate that the first HC emplacement corresponds to early stage of calcite and dolomite cementation, and the second and more important emplacement is related to fracturation processes resulting in the formation of excellent reservoirs.     

Evolution and character of supra-salt faults in the Easternmost Hammerfest Basin,SW Barents Sea

This study investigates the evolution of supra-salt faults in the Eastern Hammerfest Basin using high–quality seismic reflection data. Traditional techniques of displacement analysis, including the variation of fault displacement (throw) against distance (x), depth (z), expansion and growth indices were adopted. Fault reactivation was assessed using bivariate plots of a) cumulative throw vs. age and b) throw (t) vs. depth of nine (9) representative faults.The interpreted faults are supra-salt crestal and synclinal faults striking NE, E and SE. These faults have complicated t-x and t-z plots and are characterized by considerable stratigraphic thickening in their downthrown section. Faults in the study area have developed over the salt structure since latest Paleozoic times; some of them were reactivated by Early to Middle Triassic through dip linkage of initially isolated fault sets. Along strike, the fault exhibit complex segmentation through coalescence of several subunits linked by local throw/displacement minima. Expansion and growth indices show that the faults of the study area developed during the deposition of Paleozoic to Early Cretaceous sediments by polycyclic growth involving both blind and syn-sedimentary activity.An important piece of information from this study is that fault propagation is controlled by lithological heterogeneity and that both lateral and vertical segmentation of faults are important for hydrocarbon migration within the Triassic to Late Cretaceous interval.     

Innovation for sustainable energy from a pro-poor perspective

The development and transfer of clean energy technologies to achieve universal energy access is challenging due to the inherent complexities of the energy sector, and the energy governance and financial systems in developing economies. Innovation is an essential part of successfully addressing these difficulties. Duplicating the energy infrastructure models of developed countries will not be sufficient to meet the needs of poor consumers. To the extent that innovation can accelerate energy access, it is important to understand the specific types of innovations that are necessary and how they might be facilitated. The general features of existing international clean energy innovation systems, which are predominantly driven by the markets and emissions reduction mechanisms of developed and rapidly growing emerging economies, are reviewed and the alignment of these systems to the innovation processes required to extend energy access globally is evaluated. Drawing on the innovation policy literature, the attributes of effective international and domestic energy innovation systems that are pro-poor and the associated policy approaches are identified.