Gold has been a major economic asset for Suriname for more than a century. The long history of gold mining, concentrated in large parts of a greenstone belt in the northeast of the country, began with small-scale artisanal extraction activities and has recently seen the development of major open-pit operations. Despite the range of mining activities, Suriname's gold deposits and occurrences are under-explored from a scientific point of view. Primary gold mineralisations in the greenstone belt occur in multiple forms, and although their origin is commonly related to the Palaeoproterozoic Trans-Amazonian orogeny, the controls of ore formation in specific cases often remain obscure. This contribution presents an abridged overview of currently available information on the geological setting and characteristics for some of the main deposits where gold is extracted. In view of the consistent link between gold metallogeny and granitoid–greenstone belts in the northern Guiana Shield, the mineralised settings in Suriname are discussed in a regional context.

Spectral observations show that volcanic glass is the dominant ingredient of the aeolian landforms which cover the northern lowlands on Mars. Surface winds subject these sands to physical alteration processes in the present-day surface environment. This work highlights the role of glaciovolcanism throughout Mars’ geologic history and the parallels with landforms and materials found in Iceland. As the physical properties of Martian volcanic glass particles are difficult to constrain from orbit, Icelandic materials can provide valuable insights in their transport and modification characteristics. The processing of glass grains by environmental processes by means of the dune transport cycle is discussed. Experiments targeted the grain-size alteration effects experienced during the dune transport cycle, including the effect of ‘low-energy’ avalanching and ‘high-energy’ aeolian regimes (i.e. particle rolling and saltation). Saltation transport was found to rapidly alter grains and particle size distributions, which contributes to a positive feedback loop where the new smaller grains are mobilised more easily after fracturing and surficial abrasion. Post-depositional physical alteration therefore needs to be reconciled with the present-day silicic spectral signatures of these glasses in order to infer the relevant landform genetic. This effort is especially relevant in respect to the loss of possible signatures of biochemical alteration from microbial interactions, as glaciovolcanic environments are favourable habitats for life. As chemical and physical weathering is limited to the grain exterior, the grain interior may still retain a geochemical record of the subglacial eruption environment in which these grains were formed. Quantification of the volatiles sequestered in the glass can therefore be used to identify the formative conditions of the amorphous component in aeolian sediments.

The Boom Clay is being investigated as a host rock for disposal purposes of radioactive wastes. Although the formation is relatively uniform and homogeneous, there are embedded septaria bodies (carbonates) or layers of septaria that may constitute a problem regarding the integrity of the clay. It is therefore essential to locate these geobodies, particularly with seismic experiments. Since the medium shows strong attenuation it is necessary to correct for this amplitude loss if true amplitudes of the reflections are required when imaging these bodies after the stack. To achieve this task, we implement a reverse-time migration algorithm based on a dispersionless anelastic rheology, that is, the phase velocity and attenuation factor are frequency independent, and back-propagation is performed with a negative quality factor, Q. The algorithm is tested on synthetic data. For this we assume that the septaria are diffractors generating waves synchronously to simulate a stacked seismic section, that is, the result of an exploding-reflector experiment. In this case, back-propagation is stopped when all the diffraction points are imaged at the same time. The examples consider layers of septaria and isolated septaria embedded in homogeneous and inhomogeneous Boom Clay with zones of low Q. The amplitude of the geobodies is recovered and the resolution is improved, even in the presence of noise.

Humankind has been interested in space throughout the ages and studies of the universe and our own solar system have been ongoing since the first observations of celestial bodies. In the current era space exploration has provided in situ data for the different bodies in our solar system. To fully comprehend the underlying processes occurring in these bodies, missions and telescope observations are, however, not sufficient and additional modelling studies, both numerical and analogue, are necessary. In this paper we present a new facility specifically designed to experimentally study organic compounds under simulated planetary (sub)surface conditions on rocky bodies in our solar system: PALLAS, the Planetary Analogues Laboratory for Light, Atmosphere, and Surface Simulations. We give an overview of planetary conditions that can be simulated in this facility and that are known to affect organic compounds: radiation, atmospheric composition, temperature and surface composition.

Besides the Oligocene Boom Clay, the Ypresian clays – part of the Eocene Ieper Group (Kortrijk Formation and Kortemark Member) – are currently being investigated as an alternative host rock for the deep geological disposal of radioactive waste in Belgium and the Netherlands. In this study, broad-ion-beam milling and high resolution scanning electron microscopy (BIB-SEM) analyses were carried out to analyse the mineral fabrics and microstructures of representative Ypresian clay samples from different depths of the ON-Kallo-1 borehole (Kallo, Belgium). Qualitative microstructural observations indicate that mineral fabrics and pore morphologies in fine-grained samples are comparable to those found for fine-grained Boom Clay, but most of the Ypresian clay samples analysed also contained a significant silt fraction, which is associated with larger inter-aggregate pores, coated by a thin, very low porous clay layer. Quantitative pore-shape analysis shows lower axial ratios and elongations, as well as higher roundness and circularities for pores in the clay matrix of the more coarse-grained samples, compared to the fine-grained samples. The contribution of large pores (>1 × 107 nm² pore area) to the total BIB-SEM observed porosity was found to correlate with the non-clay mineral (NCM) content of a sample. Frequencies of pore sizes within the clay matrix follow a power-law distribution, hinting towards the possibility of up-scaling of the nanometre-scale observations to larger scale (micro-) structural features of the material. Power-law exponents are comparable to values found for power-law pore-size distributions within the clay matrix of the Boom Clay, which indicates similarity of the pore-space morphologies within the clay matrix of the Boom Clay and the Ypresian clays. Wood's metal injection, followed by (cooled BIB)-SEM analysis shows that all visible pores are connected via pore throats of diameter down to ~10 nm.

This article investigates the origin of a rare occurrence of kyanite quartzites in the Palaeoproterozoic greenstone belt of Suriname. The rocks form elongated hills in the Bosland area, Brokopondo district, where they are associated with meta-sedimentary, meta-volcanic and granitic lithologies. Their mineral content and unusual Si- and Al-rich chemical composition are inferred to be the result of advanced argillic alteration of felsic volcanic tuffs and a later overprint by regional metamorphism up to lower amphibolite facies during the Trans-Amazonian orogeny. Structurally, the Bosland area seems centred within a contractional strike-slip duplex of a major dextral fault system. The alteration was probably associated with a high-sulphidation environment and involved significant to almost complete removal of alkali and alkaline earth elements. Pseudosection modelling and textures suggest that the precipitation–temperature (P–T) history of the kyanite quartzites started with shallow (<2kbar) hydrothermal alteration of the acidic tuffaceous volcanics, possibly in the andalusite stability field (T>350°C), and ended in peak metamorphic conditions in the kyanite–staurolite stability field (P>4kbar and T=500–650°C). Alteration events that preceded the peak of Trans-Amazonian metamorphism may be more common in the rock record of Suriname's greenstone belt, which lends support to the hypothesis that gold mineralisations in the region can be pre-orogenic.

The Rupel Clay member in the Netherlands largely corresponds to the Boom Formation in Belgium, and this marine, clay-rich deposit is a potential candidate to host radioactive waste disposal facilities. Prediction of the speciation of radionuclides in Rupel Clay pore water and their retardation by interactions with Rupel Clay components requires knowledge about the composition of Rupel Clay pore water, the inventory of reactive solids and understanding of interactions between Rupel Clay and pore water. Here, we studied Rupel Clay material which was obtained from cores collected in the province of Zeeland, the Netherlands, and from drilling cuttings retrieved from a drilling in the province of Limburg, the Netherlands. Pore water was obtained by mechanical squeezing of Rupel Clay material from Zeeland. Additionally, anaerobic dilution experiments were performed in which the clay material was suspended with demineralised water or a 0.1M NaHCO3 solution. Solid-phase characterisation included determination of carbon, nitrogen and sulphur contents, measurement of cation exchange capacity (CEC) and sequential extraction of iron phases.

In contrast to the pore water in Belgian Boom Clay, pore water collected from the location in Zeeland has a higher salinity, with chloride concentrations corresponding to 70–96% of those in seawater. The high chloride concentrations most likely result from the intrusion of ions from saline waters above the Rupel Clay in Zeeland. Cation exchange during salinisation might account for the observed deficit of marine cations (Na, K, Mg) and excess of Ca concentrations, in comparison with seawater. The measured CEC values at both locations in the Netherlands vary between 7 and 35 meq(100g)−1 and are, for most samples, in the range reported for Boom Clay in Belgium (7–30meq(100g)−1).

Pore water and solid-phase composition indicate that Rupel Clay from Zeeland has been affected by oxidation of pyrite or other Fe(II)-containing solids. When coupled to the dissolution of calcium carbonates, oxidation of pyrite can account for the elevated sulphate and calcium concentrations measured in some of the pore waters. The relatively low concentrations of pyrite, organic carbon and calcite in the Rupel Clay in Zeeland, in comparison to Limburg, might be an indicator for an oxidation event. Higher contents of dithionite-extractable Fe in Rupel Clay in Zeeland (0.7–2.6mg Fe / g clay) than in Limburg (0.4–0.5mg Fe / g clay) might also be a consequence of the oxidation of Fe(II) minerals. Oxidation in the past could have accompanied partial erosion of Rupel Clay in Zeeland before deposition of the Breda Formation. However, indications are given that oxidation occurred in some of the pore waters after sampling and that partial oxidation of the cores during storage cannot be excluded. Results from dilution experiments substantiate the influence of equilibration with calcium carbonates on pore water composition. Furthermore, removal of dissolved sulphate upon interaction with Rupel Clay has been observed in some dilution experiments, possibly involving microbial sulphate reduction.

The sedimentological, metamorphic, petrographic and geochemical characteristics of the Armina Formation, part of the Paleoproterozoic Greenstone Belt of Suriname in South America, are described, based on field, geochemical and petrographic evidence obtained through fieldwork along the Marowijne River and study of diamond drill cores from Rosebel Gold Mine (RGM). The metagreywackes show characteristic features of deposition by turbidity currents: coarse-grained, poorly sorted graded greywackes, covered by fine-grained, parallel-laminated phyllitic beds, often with convolute structures and climbing ripples. Their immature character and composition suggest deposition in an arc-trench environment. In the Marowijne River three different facies of metagreywackes are distinguished: (1) the greyish Bonnidoro Falls facies, characterised by common red millimetre-sized pseudomorphs after siderite in the finer beds, (2) the green Paroe Tabiki metagreywacke facies, with decimetre-sized calcsilicate nodules, both metamorphosed in the lower greenschist facies with chlorite as the main mafic mineral, and (3) the grey Armina Falls metagreywacke facies, geochemically similar to the Bonnidoro type but of higher metamorphic grade with biotite as the main mafic mineral. The metagreywackes from the Marowijne River show a predominance of quartz, plagioclase and lithic (tonalitic) clasts, suggesting exhumation of tonalite–trondhjemite–granodiorite plutons before deposition of the turbidites. There is a slight increase in maturity from (1) to (3), suggesting increasing weathering in the source areas. The metagreywackes of the RGM (JZone) have a predominantly metavolcanic origin, suggesting that they have a different provenance area than the Marowijne metagreywackes. Geochemically the spread in composition within each facies is larger than between the facies because of the wide range in grain sizes in each turbidite sequence. A large part of the rocks from the RGM, classified by previous authors as arenites, are geochemically and petrographically metagreywackes. Only a few RGM samples are real arenites, and plot as a separate cluster in geochemical factor score plots because of their low Fe and Na contents.

One of the major scientific objectives of ESA's JUICE (JUpiter ICy moons Explorer) mission, which is scheduled for launch in 2022 and planned to arrive at the Jovian system in 2030, is to characterise the internal water ocean and overlying ice shell of Jupiter's largest moon Ganymede. As part of the strategy developed to realise this objective, the tidal response of Ganymede's interior will be constrained by JUICE's measurements of surface displacements (by the Ganymede Laser Altimeter (GALA) instrument) and variations in the gravitational potential (by the 3GM radio science package) due to the acting diurnal tides. Here we calculate the tidal response at the surface of Ganymede for several plausible internal configurations in order to analyse the relation between the tidal response and the geophysical parameters that characterise Ganymede's interior. Similarly to the case of Jupiter's smallest icy satellite Europa, the tidal response of Ganymede in the presence of a subsurface ocean, which could be as large as about 3.5 m in terms of the induced radial deformation, mostly depends on the structural (thickness, density) and rheological (rigidity, viscosity) properties of the ice-I shell. Nevertheless, the dependence of the tidal response on several geophysical parameters of the interior, in particular on the thickness and rigidity of the ice-I shell, does not allow for the unambiguous determination of the shell thickness from tidal measurements alone. Additional constraints could be provided by the measurement of forced longitudinal librations at the surface, as their amplitude is more sensitive to the rigidity than to the thickness of the shell.

Like earth and planetary scientists, most children are curious about the world, the solar system and the rest of the universe. However, for various reasons primary schools emphasise language and calculus rather than natural sciences. When science is taught, examination systems often favour knowledge of the ‘right’ answer over the process of investigation and logical reasoning towards that answer. In order to continue to spark children's curiosity and their motivation to learn and discover, science education hubs at universities and science museums could collaborate more with schools and teachers, and are beginning to do so. The objective of this position paper is to report on recent experiences in earth and planetary science education for pupils in primary and secondary education, to provide examples and inspiration for scientists. We report three examples of initiation and consolidation of science education in primary schools in the Netherlands: (1) a focus on asking questions and seeking information to reason towards the answer, initiated with a classroom game, Expedition Mundus, (2) bringing pupils and teachers together outside their school in the science museum to gain confidence and self-efficacy, and (3) having children ask their own questions and do their own research guided by the empirical cycle, for example on experimentation on sandbox scale models of channels and crater lake deltas as found on Mars. The focus on other planets, fictitious and real, stimulates pupils to ask questions about planet Earth. Finally, we argue that involvement of more scientists in science education would not only benefit primary and secondary schools and future students but also university education and science communication with society.

The Proterozoic basement of Suriname consists of a greenstone–tonalite–trondhjemite–granodiorite belt in the northeast of the country, two high-grade belts in the northwest and southwest, respectively, and a large granitoid–felsic volcanic terrain in the central part of the country, punctuated by numerous gabbroic intrusions. The basement is overlain by the subhorizontal Proterozoic Roraima sandstone formation and transected by two Proterozoic and one Jurassic dolerite dyke swarms. Late Proterozoic mylonitisation affected large parts of the basement. Almost 50 new U–Pb and Pb–Pb zircon ages and geochemical data have been obtained in Suriname, and much new data are also available from the neighbouring countries. This has led to a considerable revision of the geological evolution of the basement. The main orogenic event is the Trans-Amazonian Orogeny, resulting from southwards subduction and later collision between the Guiana Shield and the West African Craton. The first phase, between 2.18 and 2.09 Ga, shows ocean floor magmatism, volcanic arc development, sedimentation, metamorphism, anatexis and plutonism in the Marowijne Greenstone Belt and the adjacent older granites and gneisses. The second phase encompasses the evolution of the Bakhuis Granulite Belt and Coeroeni Gneiss Belt through rift-type basin formation, volcanism, sedimentation and, between 2.07 and 2.05 Ga, high-grade metamorphism. The third phase, between 1.99 and 1.95 Ga, is characterised by renewed high-grade metamorphism in the Bakhuis and Coeroeni belts along an anticlockwise cooling path, and ignimbritic volcanism and extensive and varied intrusive magmatism in the western half of the country. An alternative scenario is also discussed, implying an origin of the Coeroeni Gneiss Belt as an active continental margin, recording northwards subduction and finally collision between a magmatic arc in the south and an older northern continent. The Grenvillian collision between Laurentia and Amazonia around 1.2–1.0 Ga caused widespread mylonitisation and mica age resetting in the basement.

A groundwater model was set up to study far-field transport for the potential of a radioactive waste repository the Boom Clay in the Netherlands. The existing national groundwater model, the Netherlands Hydrological Instrument, was extended in the vertical direction to include geological formation up to and beyond the Boom Clay. As the amount of hydrogeological data in the deeper subsurface is limited, simplifications in the model schematisation were necessary. Moreover, nationwide data about the tops and bottoms of many of the deeper geological formations and their members are lacking and required interpolation. Finally, values for hydrogeological parameters, such as porosity and hydraulic conductivity, are also lacking for the deeper formations. These values were estimated using relationships with depth and lithology. Moreover, no quantitative data about heterogeneity within the deeper geological formations or its members were available.

In the Dutch research programme on the geological disposal of radioactive waste (OPERA), the post-closure safety of a generic repository is assessed in either Boom Clay or rock salt. Disposal of Dutch radioactive waste is not foreseen in the next decades and a choice of host rock has not been made. In the early, conceptual phase of the radioactive waste disposal process in the Netherlands no potential repository locations were selected and a groundwater flow model for the entire Netherlands was build. As a starting point a geological disposal facility is assumed to be present at a depth of at least 500 m within a Boom Clay formation of 100 m in order to be able to make an assessment of post-closure safety with this geological formation in a disposal concept. With these assumptions, a general idea of potential flow patterns has been obtained and broken down into pathline trajectories. These trajectories were calculated to achieve input for the potential transport of radioactive isotopes (radionuclides) from this waste in the Netherlands after the closure of a disposal facility in Boom Clay.

The groundwater flow patterns in the deeper subsurface strongly resemble the larger scale flow patterns in the shallow subsurface, with flow from infiltration areas in the east and the south of the Netherlands towards to seepage areas of the polders in the west and the northern part of the country or towards the river valleys of the Rhine and IJssel. Groundwater flow velocities, however, are much lower in the deeper part of the model and consequently travel times are much larger. The conservative travel times from the pathlines range from a few 1000 years to more than 10,000,000 years depending on the location for the repository. Longer travel times are obtained for locations with a downward groundwater flow in the Boom Clay.

Because of the simplifications in the model schematisation and the uncertainty in the model parameters, the present results should only be considered as a first indication. Moreover, the model could not be validated due to a lack of validation data. However, the insight gained with the model may help to design a data collection strategy for dedicated model validation, such as measuring the hydraulic gradient over the Boom Clay to validate downward flow in the Boom Clay to obtain the necessary data for a post-closure safety assessment.

There is increasing interest in the exploitation of the deep subsurface of the Netherlands for purposes other than conventional oil and gas production, such as geothermal energy, shale gas exploitation and the disposal of radioactive waste, so for technical and environmental reasons it is important to understand the composition of the deep groundwater. A synthesis has been made of almost 200 existing groundwater analyses for the Oligocene and older formations in the Netherlands. Three groundwater categories are considered: (1) deep oil and gas reservoirs, (2) deep, buried and confined aquifers and (3) shallower, semi-confined aquifers with or without outcrop areas nearby. No distinct water types are found but a continuous series, with Cl ranging from around 10,000 to 200,000 mg l−1: the highest concentrations are found in the reservoirs and the lowest in the semi-confined aquifers. The most saline brines are found in the northern onshore area and adjacent offshore area, where Permian and Triassic rock salt also occurs regionally in the subsurface. The groundwater is usually pH-neutral, saturated in carbonates and anaerobic. Anhydrite saturation occurs when the Cl concentration exceeds 100,000 mg l−1, and halite saturation occurs at Cl concentrations close to 200,000 mg l−1. Few tracer analyses have been done for δ2H–H2O, δ18O–H2O, δ37Cl, Br, Li and B, which makes a rigorous palaeohydrological interpretation impossible. Lithium and B may be controlled by water–rock interaction which makes them less suitable as tracers. Some of the analyses suggest that dissolution of rock salt plays a role in determining the salinity of groundwater for some deep wells in the southern part of the Netherlands, whereas other analyses suggest that evaporated seawater influences the salinity in the associated wells. Cation-exchange patterns and alkalinity to Ca ratios indicate that groundwater in the deep, buried and shallow, semi-confined aquifers is usually freshening. Six 14C analyses of samples from the buried aquifers indicate an apparent age of at least 20,000 years. Six δ37Cl analyses of formation waters from reservoirs in South-Holland suggest diffusion of Cl from a brine towards fresher water, and the associated K and also Li concentrations further suggest that these brines are related to rock salt dissolution and are not the residue of evaporated seawater. The high Ca concentrations are enigmatic for the hypersaline formation waters in the reservoirs. A limited series of samples had been analysed for various trace elements. The median concentrations are similar to the seawater and Dutch background concentration limits for shallow groundwater, but maximum concentrations can be up to three orders of magnitude higher. In conclusion, the data synthesis shows that the composition of groundwater in reservoirs and aquifers of Palaeogene and older age varies strongly in salinity at the national scale. Presence of evaporite deposits and diffusive transport seem to play important roles in controlling the salinity. Many existing analyses have no or only a few tracer analyses, that even vary among the samples. A complete suite of analyses is needed to elucidate the hydrogeological and geochemical processes that control the groundwater composition.