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This palynological study analysed 15 samples of the Tukau Formation, comprising intensely bioturbated sandy mudstone and organic-rich mudstones. Diverse vegetation types, including hinterland, mangroves, back mangroves, and montane regions, characterise the landscape of the region during the Tukau sediment deposition. Certain palynomorph types, such as Rhizophora type, Laevigatosporites sp., Elaeocarpus type, Euphorbiaceae, and Verrucatosporites usmensis (Stenochlaena), dominated the pollen assemblage, which represents the ancient landscape at that time. The influx of non-mangrove palynomorphs from the hinterland, likely transported by water, underscores the role of fluvial processes in controlling pollen distribution. Notably, the presence of age-specific marker pollen, such as Florschuetzia levipoli, Florschuetzia meridionalis, and Florschuetzia trilobata, confirms the age of the formation as Middle Miocene or younger. The presence of Acrostichum aureum pollen suggests a warm and humid tropical climate. Recognition of mangrove pollen from both front and back mangrove vegetation suggests deposition in the seaward region of the coast with significant tidal influences. [ABSTRACT FROM AUTHOR]

The Araba and Naqus formations in Ras Milan, Sinai, constitute part of the major continuous Paleozoic clastic belt stretching across northern Gondwana. They are sandstone-dominated successions, resting on Precambrian granitic basement, with lowermost thin basal polymictic conglomerate deposits (1–2 m), marking the unconformity. The Araba Formation section is composed mainly of varicoloured violet to reddish brown, fine to coarse-grained laminated and planner and overturned cross-bedded sandstones, while the overlying Naqus Formation is characterized by chaotically distributed poorly sorted quartz pebbles to cobbles within a moderately-sorted coarse- to medium-grained quartz arenite and by abundance and variety of large-scale tabular and trough cross bedding. Modal QFL classification of Araba and Naqus formation sandstones revealed that they are merely quartzose sandstones (quartz arenites). Geochemistry of the succession shows extremely wide compositional ranges for almost all major elements, but the Araba Formation is relatively enriched in SiO2, TiO2, Fe2O3*, Na2O, P2O5, and depleted in Al2O3, MgO, CaO and K2O relative to Naqus Formation. Only the Araba Formation samples are depleted in the transition elements Ni, Cr and Co and oppositely possess extreme enrichment in the HFSEs (i.e. Zr, Hf, Y, Nb, Ta, Th, U), whereas both formations show variable depletion in the LILE Rb, K and Ba, and excessive REE abundances relative to the PAAS and UCC, and LREE-enriched patterns with marked negative Eu anomalies. The provenance of the Naqus and Araba formations could be an earlier felsic magmatic source, which has undergone extensive sedimentary recycling. They possess high compositional maturity and were subjected to intensive to moderate weathering during humid climatic conditions. Passive margin tectonic setting is implied which denotes the derivation of Araba and Naqus formation siliciclastics from stable continental regions or plate interiors and deposition in intracratonic basins. [ABSTRACT FROM AUTHOR]

The Pashyian Regional stage (horizon) is the main productive unit of the middle Devonian clastic succession of the South Tatar arch. This article presents, for the first time, maps of the lower and upper parts of the Pashyian, including data on sand-shale ratio, number of sand layers (reservoirs) and thickness, based on the analysis of logging data from 25,000 wells. The maps were created by spatial interpolation of Natural Neighbor and ArcGIS Pro software.The model of sedimentation of the Pashyian Regional stage reflects the interpretation of the plotted maps as well as the synthesis of the results of detailed core investigations (lithological, sedimentological, ichnotextural, petrophysical, etc.) and analysis of archive and published materials.The main points of the proposed model are as follows. The Pashyian sediments were formed in a marine basin, in an environment comparable to that of the middle shelf of modern seas – in an offshore zone dominated by current activity. The basin floor was a relatively flat plateau, on which sandy, silty and clay sediments were simultaneously accumulated. Sediments of all types accumulated during sea transgression. Sea regression caused erosion and destruction of the already formed sediments.Positive landforms of seabed relief, composed predominantly of sandy well-sorted material, comprised autochthonous underwater sand bars, formed by constant currents parallel to the bathymetric contour of the seabed. Underwater sand bars formed extensive systems nearly throughout the entire territory of the modern South Tatar arch. At the same time, allochthonous, poorly sorted, less mature sediments were formed in underwater troughs produced by transversal currents (directed from the shore towards the sea).The proposed model explains the consistent thickness of the Pashyian Regional stage, the mosaic distribution of sand bodies over the area, and the lens-like shape of the sand and siltstone reservoirs. The model can be extrapolated to other stratigraphic intervals of the Devonian clastic succession with similar sedimentological features.

Petrological data of the recent alluvial sediments from the Ngaye River watershed in the Northern Cameroon were used in order to infer their origin with the probable source rocks as gneisses, amphibolites, and granites; and to investigate the occurrence of precious metals like Gold and Platinum Group Elements (Au-PGE). The Ngaye River watershed is located in the Adamawa plateau from the Adamawa-Yade Domain (AYD) in the Central Cameroon, Central Africa. This region is characterized by two contrasted seasons which induce a savanna vegetation cover with gallery forests along the rivers. The field works were done during the dry season. During this season, several whole fractions of sediments were sampled at six vertical lithological sequences along the right terrace of the Ngaye Rivers. The selection of samples was linked to their grain size and color. To better understand the origin of sediments, twenty-one rock samples (gneisses, amphibolites, and granites) were also collected. The grain size distribution was done using the Robinson's standard Pipetting Method. Thin sections were done for the determination of mineral assemblages and textural features of rocks using Leica DM 750P optic microscope. Mineralogical compositions of sediments were obtained using the X-ray diffraction (XRD) instrument. The major elements data were determined using the X-ray Fluorescence spectrometry (XRF). The Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) was used to obtain the concentrations of trace elements including rare earth elements and Au-PGE. The investigation of Au-PGE was done only in amphibolites as well as in the concentrate heavy minerals (160–100 µm) from sediments of lithological sequence A. Data of this paper are further presented and discussed in Ndjigui et al. [1].

This research aims to define the mineralogical composition of recent sediments that were deposited around the Al-Teeb River basin in the east Missan Governorate and try to determine the provenance or the source of these sediments. The study area represents the southeastern edge of the Mesopotamian Plain and is part of it. 15 samples were collected from eight stations of recent sediment that was deposited around the Al-Teeb River; two field works are covered (December 2019 and August 2021). Mineralogical study of the sediment after separating the light and heavy minerals by heavy liquid Bromoform in order to determine the mineralogical composition of the studied samples by using the petrographic microscope the light mineral fraction composed (95.5%) of the total mineralogy. The light components of these sediments consist mainly of quartz about 25.31%, feldspars (potash and plagioclase feldspar) about 9.53%, sedimentary rock fragments (carbonate rock fragments up to 33.39%, chert rock fragments 7.65%, evaporates fragments, 7.31%), (igneous rock fragments, and metamorphic rock fragments about 6.94%). The major component of the heavy minerals residue is opaque minerals with a range of 36.76% and non-opaque minerals with a range of 63.24%. The non-opaque minerals are mainly of chlorite 7.42%, pyroxenes composed of both orthopyroxene and clinopyroxene 6.37%, amphiboles composed of hornblende, glaucophane, and tremolite 7.02%, (mica: biotite and muscovite) 9.81%, zircon 7.54%, tourmaline 5.1%, epidote group 5.91%, rutile 4.5%, kyanite 2.2%. The sediments have two types of stability: moderately stable and ultra-stable. The mineralogical composition shows that the major sources of these sediments are; the river terraces and flood plain of the river in the Mesopotamian Plain, another source of these sediments is the aeolian deposits that separated from sand dune fields in the studied area, and outcrops of ancient sedimentary formations in the southeastern of Iraq as specified by the incidence of the carbonate rock fragments. [ABSTRACT FROM AUTHOR]

The Permian Lucaogou oil shales in the eastern Junggar Basin have long been regarded as important source rocks and reservoirs for tight oil exploration. The oil shales can also be used to assess the provenance and tectonic setting of the East Junggar region using major, trace and rare earth element geochemistry. The low chemical index of alteration ratios (37.36–64.18, 45.54 on average), low plagioclase index of alteration ratios (26.99–62.95, 42.99 on average), and high index of compositional variability ratios (0.64–1.66, 1.10 on average) suggest that the Permian Lucaogou oil shales mostly consist of immature sediments that have experienced a weak weathering intensity. The samples have low TiO2/Al2O3 and TiO2/Zr ratios that indicate a felsic origin with minor intermediate igneous rocks. The high Th/Sc and Zr/Sc ratios suggest a felsic origin without sediment recycling. The samples show fractionated light rare earth elements and relatively flat heavy rare earth elements patterns with weak negative Eu anomalies, which implies that the main provenance is lower Carboniferous intermediate–acid volcanic rocks. In addition, multiple major- and trace-element‐based discrimination diagrams show that the parent rock of clastic sediments formed mainly in a continental island arc and active continental margin environment, consistent with previous studies on the tectonic background of the East Junggar region during the late early Carboniferous. Immature sediments are present in the Permian Lucaogou oil shales and have a weak weathering intensity. The provenance of the clastic sediments of the Permian Lucaogou oil shales was predominantly early Carboniferous intermediate–acid volcanic rocks. The clastic sediments of the Permian Lucaogou oil shales were developed in a continental island arc and active continental margin environments. The Permian Lucaogou oil shales provide crucial information for tectonic setting and evolution of the northern Xinjiang during the Carboniferous–Permian. [ABSTRACT FROM AUTHOR]

The Upper Tukau Formation is exposed along the Sungai Rait Road and can be described as follows: the lowermost member is formed by soft clay and silt, the "Brick Shale", and contains meandering sandy channels. The clay is thoroughly excavated in the area and used as raw material for bricks. The second and hilltop-forming layer is built by relatively hard amalgamated, and partly channelized sandstone layers, often lined with diagenetically precipitated iron minerals (i.e., pyrite and siderite concretions). The youngest member is characterized by intertidal channels and mud flats. Geochemical studies point to a polymictic source of already recycled sediments, deposited in predominantly oxic, partly suboxic environments, with rapid transitions observed from one milieu to the other. In broad terms, the entire sequence appears to be a shallowing-upwards cycle, leading from subtidal to intertidal realms. The surprising sharp boundaries between clay and sand packages are discussed and may be related to climate cycles. [ABSTRACT FROM AUTHOR]

The depositional environment of Clastic sediments in Tomboy Field Onshore Niger Delta were delineated using 3D Seismic and lithological logs. Well log suites from 5 wells comprising Spontaneous potential, Gamma ray, Sonic, Resistivity, Density, and Neutron logs were obtained and analyzed. Reverse estimation was done for the Neutron log and Bulk Density log using volumetric method. Gamma-ray log were used to calibrate Log motifs and correlate sand bodies TMB-01, TMB-02, TMB-03, TMB-04, and TMB-06. Prediction of depositional environment was made through the usage of wireline log shapes of facies combined with result from seismic data. Results of correlation across the five wells showed that. there was continuity at depth interval of 4000-5000ft across the wells as well 3 did not have any gamma information to correlate accros it. The seismic section showed two major growth faults and a channel fill on seismic (inline 5940, crossline1660) between 3.3-3.6ms. According to the paleo-reconstruction from the correlated wells within the tomboy field, the reservoir is made up of sands from fluvial and tidal channels, barrier, and barrier bar. These sand bodies are likely to contain hydrocarbons because of the rollover anticline, which is found at the fault’s downthrown block. This study has revealed that the Clastic sediments in Tomboy Field Onshore Niger Delta were deposited within a predominantly deltaic environment (transitional).

The paper presents petrographic, geochemical, and new U-Pb zircon (LA-ICP-MS) geochronological data on the Upper Lena Fm. sediments which make part of the Cambrian sedimentary cover of the Siberian craton. The composition of lithic fragments in these clastic sediments, including mafic and felsic volcanics and granitoids, along with the correlation of major element ratios and the values of trace-element ratios point to predominant igneous (mainly felsic) rocks in the provenance. The U-Pb ages of detrital zircons from the sampled Upper Lena Fm. sandstones are mostly Early Paleozoic (∼500 Ma), with very few Archean-Paleoproterozoic determinations and quite many Neoproterozoic zircons. Ediacaran and Earliest Cambrian clastic sediments bearing Early Precambrian and Neoproterozoic detrital zircons, as well as Neoproterozoic and Early Paleozoic complexes of the Central Asian Orogenic Belt, could provide material for the Upper Lena clastic deposition. The geochronological evidence shows that the Upper Lena Fm. sandstones were deposited over vast territories of the southern Siberian craton in the Late Cambrian, in a single sedimentary basin, and originated from the same provenance. The Upper Lena deposition event in the Late Cambrian, immediately before the Ordovician period, makes a key milestone in the geological history of Siberia: the end of a large-scale Early Cambrian transgression and the beginning of gradual uplift of the southern craton margin, at least till the Carboniferous, which was associated with the formation of the Central Asian Orogenic Belt, a major tectonic unit of Asia.

We invert infrasonic timeseries produced by a single buried chemical explosion detonated as part of the Source Physics Experiment phase II Dry Alluvium Geology (DAG). The key to our inversion is that we use a three dimensional, fully coupled, linear, elastic-to-acoustic forward model to predict the recorded acoustic wavefield. We assume that the fourth buried chemical explosion in the series, DAG-4, produces an atmospheric acoustic wavefield due to a combination of direct elastic-to-acoustic coupling at the air-earth interface and ground upheaval, or spall, at the Earth's surface. In our linear model we approximate these two phenomena with distinct source terms separated in space and time: (1) a buried point source consisting of six source time functions, each corresponding to a single component of a generalized moment tensor and (2) a vertically directed, time-variable force applied to the Earth's surface. Inverting the infrasonic data with this linear forward model results in estimated source parameters that accurately predict the observed infrasound signals. To test our estimated buried source, we use the Rayleigh integral (RI) to model the infrasound signal from the measured and predicted acceleration surfaces. First, we simulate the infrasound signal waveforms using vertical accelerometer data and find that these closely match the observed infrasound. Next, using the estimated buried seismic source model without spall, we estimate the acceleration of the Earth's surface using a linear approximation. When using the predicted surface acceleration in the RI, we simulate infrasound signals that reproduce pulse shape characteristics but not the amplitude of the observed infrasound, indicating our linear model does not completely account for nonlinear spall effects. Based on these results, we argue that for the scale of this experiment, purely linear models can estimate seismoacoustic source attributes and predict the far-field infrasonic signal, but the primary contribution to the infrasonic signal is the spall source. [ABSTRACT FROM AUTHOR]

Heavy metal pollution is one of the serious problems resulting from the rapid increase in human activities that can accumulate to reach critical levels threatening food sources for humans and other living organisms. Therefore, the concentrations of major and trace elements in recent clastic sediments from the coastal area between the Sarada River mouth and the Gosthani River mouth, east coast of India were analyzed using XRF and ICP-MS techniques to identify the natural and anthropogenic sources of these elements. The results showed that silicate concentrations range between 53.25 wt.% and 82.36 wt.%, where the concentrations decrease from south to north along the beach; whereas the concentrations of iron, aluminium, and titanium increase in the same direction, consistent with the increase in concentrations of heavy minerals. The depletion/enrichment values showed that Ti, Fe, and Mn were enriched in the sediments from the study area in comparison to other major elements. The elevated values of contamination factor of the toxic trace elements are closely related to human activities in the surrounding areas, where the high concentrations of toxic elements, such as cadmium (CF = 173.2), zinc (74.36), lead (32.05), copper (26.44), and cobalt (25.75), have been observed in the area near Visakhapatnam port which are associated with port operations, industrial waste, and sewage. The factorial analysis method partly succeeded in linking the trace elements of the same source, as it was possible to identify elements of natural origin from those of anthropogenic sources and track their sources. [ABSTRACT FROM AUTHOR]

The mineralogical and geochemical composition of the Silurian Akkas Formation consisting of interbedded shales, sandstones, siltstones and rare marls from the western desert of Iraq was investigated based on geochemical and petrographic data to constrain their weathering condition, palaeoclimate, provenance and tectonic setting. Based on petrographic and SEM analysis, sandstones are dominated by quartz with rare rock fragments, mica and feldspar, whereas clay minerals assemblage is dominated by illite and kaolinite with a lesser amount of chlorite in shales and chlorite with a minor amount of illite, kaolinite and mixed layer illite/smectite in sandstones. The chemical index of alteration (high CIA), the index of compositional variability (ICV < 1), plagioclase index of alteration (high PIA) values and A–CN–K plot suggest mainly intensely chemically weathered source area. The elemental ratios critical for palaeoclimate (Sr/Cu and Ga/Rb) and Ga/Rb vs Sr/Cu plot in addition to clay mineral evidence indicate fluctuating climate between humid and arid conditions, which was affected by the extensive Late Ordovician–Early Silurian glaciation (Hirnantian glaciation event) during the deposition of the Akkas sediments. The geochemical data from major, trace and REE elements, as well as bivariate discrimination provenance diagrams, suggest mainly felsic–intermediate igneous source rocks. The mineralogical composition of sandstones (high quartz content, rare feldspar and rock fragments) and the high geochemical maturity of shales and sandstones indicate that they were derived from stable cratonic source and recycled orogeny with the possible contribution from quartz-rich crystalline provenance. These sources were likely the plutonic–metamorphic complexes of the Arabian Shield located to the southwest of the Akkas basin. The detrital mode tectonic provenance diagram, discriminant function-based major element diagrams and REE concentrations suggest continental margin/intracratonic depositional setting mixed with an older collisional source, which is consistent with the general geology of the study area. [ABSTRACT FROM AUTHOR]

The Ballık area (SW Turkey) was studied as a mixed clastic–continental carbonate reservoir analogue, in which kilometre wide and up to 70-m-thick tufa and travertine lithologies are found in an envelope of detrital sediments, which locally strongly interfinger with these porous carbonates. Former studies focussed on the carbonate lithologies, since they are considered as pre-salt analogues. This study aims to describe the adjacent non-carbonate lithologies, unravel their depositional setting, and address their influence on the overall sedimentary architecture. This study relies on an extensive field campaign, during which 142 samples of all different detrital lithologies were collected. Optical, fluorescence, cathodoluminescence, and Scanning Electron Microscopy (SEM) yielded important insights in the petrography of these lithologies, based on which 5 main lithologies were differentiated: i.e., (1) laminated marls, (2) polygenetic conglomerates, (3) massive marls, (4) tabular sandstones, and (5) coquina accumulations. These were interpreted to represent three different sedimentary facies corresponding to lacustrine, fluvial, and shoreline facies. The (clay) mineralogy of lacustrine sediments was extensively studied by bulk and clay-specific XRD. In this respect, special emphasis was laid on the depositional setting of the lacustrine facies, in which both authigenic palygorskite and poorly ordered dolomite were identified. Petrophysical properties of 16 plugs were determined by He porosimetry and N2-permeability, indicating that the detrital sediments are characterised by poor reservoir properties. The latter causes them to act, after assumed burial compaction, as potential barriers within a continental carbonate reservoir system. [ABSTRACT FROM AUTHOR]

The Ground Penetrating Radar (GPR) method potentially offers many possibilities for fast and reliable lithostratigraphic sediment models to be developed. From a cognitive point of view, this represents a major simplification and shortening of procedures with which information about sediments can be obtained. And from the point of view of the economy of operations, there can be a significant reduction in costs and time of research in shallow geology and the stratigraphy of areas where unconsolidated clastic sediments are of superficial occurrence. Also noteworthy is the possibility for the results of GPR surveys to be deployed in support of geological mapping, as well as in the shallow exploration of resources and hydrogeological studies. The most major advantage of the GPR method related to the possibility of the structure of forms being observed in full shape. In the absence of large outcrops, geophysical prospection of geomorphological forms is helpful, insofar as we are able to translate the results of geophysical surveys into the actual lithostratigraphic system of sediments building a specific form. Against that background, the research presented in this article forms part of the work to develop radar stratigraphy, as an important support for direct geological research (Huggenberger et al., 1994; Van Overmeeren, 1998; Beres et al., 1999, Overgaard and Jakobsen, 2001; Jakobsen and Overgaard, 2002; Neal, 2004; Lejzerowicz et al., 2014; Żuk and Sambrook Smith, 2015; Lejzerowicz et al., 2018). It also points to the research potential of the GPR method in determining the genesis of form. The discussion on the way kames form (and even as regards the way they should be defined) has been going on in the literature for years (Niewiarowski, 1959; 1961; Karczewski, 1971; Klajnert, 1978; Jaksa, 2003; Terpiłowski, 2008). The studies presented here do not suffice to allow the matter to be determined comprehensively, even though they do provide for verification of the opinions of previous researchers. An example would be the observation of numerous faults in the whole mass of the western Owieczkowo kame (Fig. 7A), with this attesting to the creation of the form on ice, rather than on mineral ground (Niewiarowski, 1959). [ABSTRACT FROM AUTHOR]

This study was performed on 663 sandstone core and cutting samples taken from the Silurian-Devonian succession in five wells, located in eastern Saudi Arabia. This study aimed to correlate the Tawil Formation in the study wells, defining the lower Qalibah/Tawil and upper Tawil/Jauf boundaries. The Tawil Formation is mostly characterized by clastic-dominated fluvial to marginal marine depositional environments. A chemostratigraphic correlation workflow was established using key element ratios and comprising four zones (C1 to C4) and five subzones (C2-1 to C2-3 and C3-1-C3-2). The chemostratigraphic zonation allowed robust characterization of stratigraphy in the uppermost Qalibah, Tawil, and lower Jauf Formations. Zone C1 is associated in most cases with the Sharawra Formation. Zones C2 and C3 are generally linked with the Tawil Formation, and Zone C4 broadly defines the lower part of Jauf Formation. In detail, the chemostratigraphic zonal boundaries do not precisely match the biostratigraphical and lithostratigraphic boundaries, indicating that the C1-C2 and C3-C4 boundaries are probably time-transgressive. The ratio Zr/Nb was used to model sequence stratigraphy. This ratio can vary in proportion to grain size, in which the element Zr is known to be concentrated in the heavy mineral zircon; while Nb-bearing heavy minerals along with clay minerals, likely illite, produce Nb. The increasing Zr/Nb ratio values are considered to define the coarsening upward or regressive sequences while decreasing Zr/Nb trends can mark fining upward or transgressive sequences. [ABSTRACT FROM AUTHOR]

Geological prospection of partly accessible constructional pit for the hydroelectric power plant (HPP) Brežice was performed. Paleontological content and sediment-petrographic characteristics of rocks were investigated. Neogene part of the succession consists of carbonate silt and siltstone with intercalations of carbonate and silicate sandstone, and polymict sandstone to conglomerate. Based on foraminifera, ostracods, molluscs and marine mammals, the Upper Badenian and Lower Sarmatian age of beds and boundary between them have been determined. The transition is characterized by a shorter break in sedimentation and environmental change. Fossil fids indicate that salinity and depth of sedimentary basin were oscilating in Sarmatian, but in general decreasing. Quaternary cover beds consist of gravelly, sandy and silty deposits of the Sava River.

Abstract The late Triassic-early Cretaceous deep-sea sedimentary succession exposed in western Cyprus is used here to help understand the wider context of continental break-up and seafloor spreading in the easternmost Mediterranean region. The restored sequence begins with late Triassic, base-of-slope sandstone turbidites and mudrocks, and fines upwards into mudrocks, distal calciturbidites and metalliferous sediments. After a hiatus, late Jurassic-early Cretaceous non-calcareous mudstones and radiolarites accumulated beneath the carbonate compensation depth, together with redeposited shallow-water-derived carbonates, including calcirudites. The succession culminates in late Jurassic-early Cretaceous very thickly bedded and highly mature quartzarenites that accumulated by mass-flow processes. The fine-grained siliciclastic sediments are terrigenous in origin, as indicated by whole-rock, trace element and REE analysis. Fe, Mn and trace metal enrichment in the late Triassic represents hydrothermal input related to submarine volcanism that was probably triggered by the nearby onset of seafloor spreading. The late Triassic sandstones were derived from a low to intermediate-grade metamorphic source terrane. The late Jurassic-early Cretaceous sandstones reflect extreme physical and chemical maturity in the source area, followed by transport and mass flow to a deep-water base-of-slope setting. Regional facies variation and locally available palaeocurrent data suggest sediment supply, originally from a continental block, no more than tens of km to the west or north. Similar successions are exposed in W Turkey, represented by the Antalya Complex. In the light of alternatives, the sedimentary succession is restored as the base-of-slope apron of a rifted microcontinental block, adjacent to the northern margin of the S Neotethys. The overall succession indicates (unstable) passive margin development after regional latest Triassic-early Jurassic continental break-up, with implications for plate reconstructions and hydrocarbon exploration. [ABSTRACT FROM AUTHOR]

Abstract A combined study of facies and diagenesis variations was carried out with the aim to understand small-scale heterogeneities in porosity and permeability of sandstones within a 219 m completely cored Middle Buntsandstein succession from central Germany. The well Erfurt 1/12 (EF-FB 1/12) allows studying aquifer quality variations by taking 49 plug samples of fresh rock material for thin section analyses and petrophysical measurements. This potential Buntsandstein aquifer is composed of varying portions of sandstones, mudstones and sandstone-mudstone interlayers, which were deposited on a large terminal fan system and in a large playa-lake in the basin centre. A fluvial channel and a sandflat depositional environment can be distinguished. Both are composed of varying amounts of channel-, sandsheet- and floodplain sediments of mainly massive, cross-bedded, horizontally laminated and ripple cross-bedded sandstones. Best aquifer potential occurs in the horizontally laminated and cross-bedded sandstones within channels of the fluvial environment, and in the massive sandstones of channels in sandflat deposits. Aquifer quality does not decrease with increasing depth or stratigraphic position. Instead, it is controlled by grain size and diagenetic evolution. Four diagenesis types were distinguished: (1) cementation type (CT), (2) leaching type (LT), (3) illite type (IT) and (4) mixed type (MT). Best aquifer quality was found in the leaching type (LT) consisting of larger grain sizes (medium sand), which led to the formation of a large primary pore network. Our data suggest a strong relation of hydraulic parameters not only with different facies types, architectural elements and depositional environments, but particularly with compaction and cementation during burial, and dissolution by meteoric water during subsequent uplift history. Thereby, present horizons with good hydraulic properties relate to this complex interaction of sedimentary facies and diagenetic evolution, but are restricted to only very local areas with no relevance for basin-wide fluid flow in the subsurface. Highlights • Highest permeability values are in fluvial horizontal laminated channel sandstones. • Poor aquifer potential occurs in horizontal laminated sandflat sandstones. • Improved hydraulic properties relate to cement leaching during uplift. • Good aquifer quality is restricted to small isolated areas/volumes. • Horizons with high aquifer potential have no relevance for basin-wide fluid flow. [ABSTRACT FROM AUTHOR]

The implementation of CO 2 storage in sub-surface sedimentary formations can involve decision making using relevant numerical modelling. These models are often represented by 2D or 3D grids that show an abrupt boundary between the reservoir and the seal lithologies. However, in an actual geological formation, an abrupt contact does not always exist at the interface between distinct clastic lithologies such as sandstone and shale. This article presents a numerical investigation of the effect of sediment-size variation on CO 2 transport processes in saline aquifers. Using the Triassic Bunter Sandstone Formation (BSF) of the Southern North Sea (SNS), this study investigates the impact a gradation change at the reservoir-seal interface on CO 2 sequestration. This is of great interest due to the importance of enhanced geological detail in reservoir models used to predict CO 2 plume migration and the integrity of trapping mechanisms within the storage formation. The simplified strategy was to apply the Van Genutchen formulation to establish constitutive relationships for pore geometric properties, which include capillary pressure ( P c ) and relative permeability ( k r ), as a function of brine saturation in the porous media. The results show that the existence of sediment gradation at the reservoir-seal interface and within the reservoir has an important effect on CO 2 migration and pressure diffusion in the formation. The modelling exercise shows that these features can lead to an increase in residual gas trapping in the reservoir and localised pore pressures at the caprock’s injection point. [ABSTRACT FROM AUTHOR]

Differentiating between regularly seasonal, irregular and event-based clastic sedimentation is difficult if sedimentation structures resemble and dating methods are imprecise. In this study - clastic light and dark laminae from lava-dammed Paleolake Alf in the Late Pleistocene in the Quaternary West Eifel Volcanic Field are analyzed to clarify how they formed and if they are of annual origin and comparable to assumed periglacial varves from neighboring Lake Holzmaar. Therefore, a multiproxy approach is applied combining sediment thin section analysis which focuses on composition and structure with 14 C dates. The results are compared to recently-formed annually-laminated clastic sediments of, e.g., the High Canadian Arctic. Observed sedimentation structures reveal sediment delivery by over- and interflows and deposition from suspension forming two characteristic microfacies: Type I graded laminae and Type II laminae with graded sublayers. Additionally, erosional bases and event deposits indicate episodic underflows. Thus, lamination is potentially seasonal but is significantly veiled by extreme runoff causing erosion and resuspension processes or a mixed water body preventing sediment delivery into the lake basin. However, sedimentation processes between watershed and lake could be reconstructed by comparing recent and paleosediment structures. [ABSTRACT FROM AUTHOR]

Fine-grained sediment deposition is often conceived to happen in still water conditions and to represent slow sedimentation rates. However, it has been increasingly noted that mud sedimentation commonly occurs under high-energy conditions. The macrotidal Petitcodiac River estuary is used as an example to investigate the significance of flocculation as an important process in the rapid removal of large amounts of sediments from suspension under turbulent flow conditions. A range of physical sedimentary structures was observed at the Petitcodiac River estuary intertidal flats and bars, including low-angle and horizontal planar lamination, current and climbing ripples, surficial fluid mud, soft-sediment deformation, microfaults, and mud rip-up clasts. Fluid mud within the study area contains considerable proportions of clay (21-67%) and contributes to the formation of creeping fluid-mud sheets and streams. Detailed examination of the naturally occurring clay flocs shows that they contain up to 77% of the entangled silt- and sand-sized grains. SEM and microscopic imaging of fluid mud reveal a substantial amount of bioclastic material within the flocs and dispersed among the sediments. These observations show that physicochemical and biological processes influence silt, plankton, and clay aggregation. Water samples and observations from the Petitcodiac River estuary confirm that flocs form in the water column and then settle to the tidal-channel floor and flanking intertidal flats. Laboratory experiments, using Petitcodiac sediment, show how the clay flocs have the potential to sweep the water of silt-sized suspended grains. Additionally, diatoms and their associated extracellular polymeric substance (EPS) sheaths might play a role in mineral aggregation and increased sediment cohesiveness. [ABSTRACT FROM AUTHOR]

Multiproxy analysis of detrital minerals is a powerful tool for unravelling the source-to-sink evolution of syn-rift sedimentary basins that represent important depositional settings during major rift events. The Cenozoic Resende half-graben in SE Brazil is a classic example of a syn-rift basin developed under oblique extension, which preserves evidence of tectonic episodes and palaeoclimatic conditions during the opening of the Atlantic. Sediment in the basin was sourced from the surrounding basement rocks, which to the faulted margin consists of older Proterozoic orthogranulites and orthogneisses, whilst to the flexural margin is characterised by Neoproterozoic passive margin paragneisses. Cretaceous intra-plate alkaline stocks crop out at the western edge and in the central-south basement of the basin and represent a distinct provenance fingerprint. This study uses new detrital zircons U–Pb ages combined with previously published elemental and Nd and Sr isotopic data to characterise the sedimentary provenance of Eocene alluvial deposits and to understand how sediment sourcing has changed throughout the evolution of the basin. U–Pb detrital zircon analyses from samples collected across the Resende Basin are presented herein. Samples yield a spread of detrital age spectra from the Archaean to the Cretaceous. Precambrian zircons range from ca. 3228 Ma to ca. 542 Ma. Cretaceous zircons yield ages between ca. 138 Ma and ca. 67 Ma. The sediment source location is interpreted by comparing the yielded detrital zircon spectra with the age spectra of zircons from the basement rocks. The dominance of detrital zircons yielding ages of ca. 1500 Ma and ca. 1000 Ma is interpreted to be sourced from the Neoproterozoic basement rocks to the flexural border of the half-graben. Cretaceous zircons from samples with whole rock εNd 40Ma > −10 are found in both the western and eastern portions of the half-graben but not in the central portions. It is interpreted that an along-axis fluvial system was responsible for a small increase in the compositional maturity of the Resende sandstones from west to east, resulting in the progressive dilution of Cretaceous alkaline igneous detritus along the basin axis. Preserved metamorphic rims in zircon grains indicate low transport abrasion, suggesting that Cretaceous zircons in the eastern depocentre could be associated with other small proximal sources. U–Pb zircon analyses and Nd and Sr isotopes provide reliable insights regarding sediment provenance and transport processes, whilst element geochemistry supplies evidence for hydraulic sorting effects. Consequently, the data represents a more robust estimation of the provenance patterns of the Resende Basin, showing chemical and geochronological differences that support the division of the basin into three depocentres (western, central, and eastern) connected by a longitudinal fluvial system sourced mostly by sediments coming from the south-western flexural border. This study highlights the usefulness of using multiple provenance proxies to unravel the complex development of rift basins, assessing multiple source terrains and the variable degrees of mixing in sedimentary basins. [Display omitted] • Unravelling syn-rift sedimentary basins' source-to-sink behaviour • U–Pb detrital zircon dating reflects proximal source areas in a continental rift basin. • Palaeogeographic reconstruction and the role of a longitudinal fluvial system [ABSTRACT FROM AUTHOR]

The stratigraphic classification and correlation of Permian-Lower Triassic clastic beds in the Central European Basin System traditionally rely on geophysical, bio-, and lithostratigraphic methods. However, in basin margin areas, the accuracy of these tools is diminished due to the heterogeneous distribution of stratigraphic markers, lack of index fossils, and greater climatic and tectonic disturbance. To overcome these limitations, this study introduces a more versatile, multifaceted and chemostratigraphy-based approach. By integrating results from bulk X-ray fluorescence analysis, sandstone petrography, Raman heavy mineral analysis, lithofacies characterisation and borehole gamma-ray logs, we produce robust multi-stratigraphic schemes for selected sequences in the Franconian Basin (SE Central European Basin System). Hierarchical chemostratigraphic zones, comprising five chemozones and sixteen subzones, were designed using key elemental ratios (Ga/Rb, Rb/K, Na/K, Ca/Mg, Cr/Ti, Th/Ti, Nb/Th, Ti/Nb, P/Ti, Zr/P, Zr/Y), whose changes through time reflect modifications in the mineralogical composition of sedimentary rocks. To ensure precise interpretations of geochemical data, we established links between mineralogical and chemical components through statistical processing and direct comparison with mineralogical assemblages. Our results demonstrate that chemostratigraphic boundaries can identify major changes in palaeo-depositional environments and sediment sources induced by eustatic, tectonic and climatic disturbances. For example, changes in the P/Ti and Zr/P ratios across the CP3-CT1 document the increased abundance in apatite-rich granitic detritus, resulting from the exposure of new source lithologies in the catchment area due to Early Triassic synsedimentary tectonism. Since these perturbations had a regional impact on sedimentation, their geochemical fingerprints are correlated across the basin, regardless of lithofacies variability or distance between sections. Moreover, integrating characteristic geochemical signals into multi-stratigraphic schemes enables more precise placement of stratigraphic boundaries, identification of locally deposited/preserved stratigraphic markers, and overall refinement of outdated classification schemes. The chemostratigraphic approach introduced in this study offers a solution to the limitations of conventional stratigraphic tools, allowing robust characterisations and correlations of Permian-Triassic sequences in the marginal regions of the Central European Basin System. In addition, the multi-analytical workflow for processing geochemical data, refining stratigraphic schemes and attributing geochemical anomalies to environmental perturbations represents a further step towards more precise applications of chemostratigraphy to the depositional record. [ABSTRACT FROM AUTHOR]

The Divje babe I cave is world known Paleolithic site in western Slovenia. In this paper, special interest is given to the identification of sedimentary hiatuses in karst infillings. Hiatuses can be the most reliably identified by detailed radiometric dating throughout the profile. However, this method is very expensive from economical point of view. New approach was developed in Divje babe I cave. Study of morphological characteristics of clast, may revealthe position of hiatuses. Four presumable hiatuses were assessed in sedimentary profile ranging from depth - 281 cmto - 481 cm below the contemporary ground floor in Divje babe I cave. Two hiatuses can be confirmed by results of radiometric datings, but another two hiatuses are doubtful. However, the identification of hiatuses by radiometric dating greatly depends on vertical length between two dated levels. Larger the length, greater the probability that hiatus was overlooked. Reliability of two presumable hiatuses can be confirmed by additional radiometric datings or with another analysis, such as measurement of degree of weathering.

The great November 5, 1985 Potomac Valley flood was responsible for the release of 1800 m3 of alluvial and colluvial sediment from the walls of the entrance doline of Mystic Cave. Flood waters were sufficiently powerful to flush the entire mass of sediment not only into the cave but through the cave. Remnants of the sediment mass in the form of sand bars and a few cobbles wedged in speleothems were the only evidence in the cave that the huge mass of sediment had moved through. The sediment moved as a suspended mass in water moving at peak velocities of many meters per second. Present day cave sediments must be interpreted with the understanding that entire sediment fillings can be transported or rearranged by single extreme events.

Geological prospection of partly accessible constructional pit for the hydroelectric power plant (HPP) Brežice was performed. Paleontological content and sediment-petrographic characteristics of rocks were investigated. Neogene part of the succession consists of carbonate silt and siltstone with intercalations of carbonate and silicate sandstone, and polymict sandstone to conglomerate. Based on foraminifera, ostracods, molluscs and marine mammals, the Upper Badenian and Lower Sarmatian age of beds and boundary between them have been determined. The transition is characterized by a shorter break in sedimentation and environmental change. Fossil finds indicate that salinity and depth of sedimentary basin were oscilating in Sarmatian, but in general decreasing. Quaternary cover beds consist of gravelly, sandy and silty deposits of the Sava River. [ABSTRACT FROM AUTHOR]

Miano gas field is one of the prominent gas-producing fields of the Middle Indus Basin, SW Pakistan. The Lower Goru is the distinct reservoir that is producing hydrocarbons for the last two decades. This study attempts to characterize the Goru reservoir using preliminary seismic interpretation to the 2D seismic profiles of the Miano gas field Pakistan. The velocity models confirm the presence of possible hydrocarbon bearing sands within the reservoir interval of interest. The Iso-pach map of the Lower Goru coincides with the identified low velocity zones. The massive clean sands are identified on the NE and the SE flanks within the reservoir zone. The well correlation show the maximum sand thickness near the well 02, suggesting the possible locations for the future oil and gas explorations. [ABSTRACT FROM AUTHOR]

Major, trace, and some rare earth element compositions in clastic sediments of the Dibdibba Formation (Late Miocene-Pleistocene) in central and southern Iraq have been investigated to describe the sedimentary environment and provenance. These sediments are classified as subarkosic to arkosic with few sublithic arenite, lithic arenite, and gray wacke; they are mainly composed of quartz (Q) followed by feldspar (F) and rock fragments (L) with a petrologic composition of Q73-F21-L6. The Arabian Shield is a probable source of the studied sediments which are derived from multi-sources including igneous rocks (felsic to mafic) and metamorphic rocks and were transported by river currents towards the northeast. Eventually, the clastic sediments were deposited in a fluviatile environment covering a wide area in Saudi Arabia, Kuwait, Qatar, and Iraq during the Late Miocene-Pleistocene. They were developed on a passive continental margin under a semi-humid climate alternating with drought periods. The grain size analysis indicates that Basra in the south of Iraq is close to the source, but Karbala and Najaf in central Iraq are farthest from the source. [ABSTRACT FROM AUTHOR]

Potočka zijalka was a station of Aurignatien hunters and the site of rich fossil remains of Pleistocene large mammals. Clastic sediments were deposited in Würm and are an intimate mixture of gravel, sand, silt and clay occurring in various proportions. Thefractions form distinct populations, which were transported by different agents, like rockfall, flowing water, ephemeral torrent flows and cryoturbation. The sediment constituents are petrologically rather diverse and indicate that they were derived from different parent rocks - Mesozoic limestone, Permian-Carboniferous shales, Tertiary fine-grained sediments and fluvial pebbly deposits.Bulk chemical composition is strongly influenced by the limestone component, but the majority of trace elements, like Ti, Li, V, Fe, Co, Zn, Ga, Y, REE, Zr, Nb, Cs, Hf and Th originates from clay and fine silt, and Mn, Pb, Ni, Cu and Sn mainly from the heavyminerals in the sand fraction. Ca, Mg, Br, Rb, Sr and U show strong correlation with the amount of carbonate component. Rare earth elements, normalised to PAAS are not appreciable fractionated and show light positive europium anomalies.

Clastic sedimentary features of beachrocks and unconsolidated deposits of parent beaches were investigated along the northern Aegean coastline (Greece) to assess their suitability in palaeo-environmental reconstruction. Twelve paired datasets were collected in the Thermaikos, Toroneos, Siggitikos and Ierissos gulfs of the Chalkidiki Peninsula, the adjoining Kavala Gulf and Thassos Island, comprising beachrock cores and companion beach subsurface sediments. Particle size analyses based on univariate and bivariate statistics suggest that, during the time period of beachrock formation, depositional conditions differed distinctly from those of the modern parent beaches. The results imply difference of maturity level of beach evolution from the time of cementation (coarser materials-early stage of beach formation) to modern situation (finer materials-reworked and 'mature' beach sediments). Furthermore, the findings indicate increasing coastal protection due to beachrock exposure in the modern swash zone. In conclusion, it is suggested that textural analysis of beachrocks in comparison with unconsolidated sediments of the parent beach might provide information regarding differences of coastal depositional regimes and future research could focus on specific-layer analysis and comparison. [ABSTRACT FROM AUTHOR]

Abstract: Sedimentary geology can shed light on the processes of continental collision. The easternmost Mediterranean provides an exceptional opportunity to study sediments deposited during progressive and diachronous continental collision, with implications for comparable settings elsewhere. Here, we focus on sediment sources, pathways and deposition of mostly deep-sea clastic sediments exposed in northern Cyprus. The sedimentary basin forms part of the northern continental margin of the Southern Neotethys ocean and is represented by a ca. 200km-long, E–W-trending, arcuate lineament, encompassing northern Cyprus and its submarine link with Turkey. The Upper Eocene–Upper Miocene basin was divided into northerly and southerly sub-basins during Mid- to Late Miocene time by an E–W-trending, inferred syn-depositional fault lineament. The sequence begins with non-marine to shallow-marine basal conglomerates (Late Eocene) that abruptly fine upwards into siliciclastic turbidites (Oligocene), followed by biogenic calciturbidites and marls (Aquitanian–Langhian). During Mid–Late Miocene the northerly sub-basin was characterised by thin- to medium-bedded calciturbidites and marls (Serravallian), overlain by thick-bedded, medium-grained lithic sandstones (Tortonian). In contrast, the southern sub-basin is dominated by siliciclastic turbidites with abundant sole structures (Burdigalian–Tortonian). Palaeocurrent evidence indicates dominantly westward sediment transport, especially during the Late Miocene. The Serravallian–Tortonian sandstones of the northern sub-basin are relatively rich in carbonates, while the southern sub-basin contains more siliciclastic and ophiolite-derived detritus indicating differences in sediment supply. In general, the Upper Eocene basal conglomerates were mainly derived from the north, from within the Girne (Kyrenia) Range and its inferred northward extension. In response to rapid subsidence (reflecting possible southward subduction zone retreat) clastic sediment sources to the north then submerged while clastic sediment was instead mainly supplied from the South Neotethyan suture zone to the east and northeast in southern Turkey. Reflecting diachronous collision, deep-water deposition persisted in the easternmost Mediterranean basin further west until this was terminated in northern Cyprus by thrusting/folding during latest Miocene–earliest Pliocene. Quaternary collision-related uplift ensued. Similar sedimentary development is to be expected in collisional settings elsewhere (e.g. Tethyan closure in the Himalayas; Iapetus closure in the Appalachians). [Copyright &y& Elsevier]

A sedimentological investigation of the Neogene deposits of the Zagros foreland basin in SW Iran reveals a continuous and largely gradational passage from supratidal and sabkha sediments at the base (represented by the Gachsaran Formation) to carbonates and marine marls (Mishan Formation with basal Guri carbonate member) followed by coastal plain and meandering river deposits (Agha Jari Formation) and finally to braided river gravel sheets (Bakhtyari Formation). This vertical succession is interpreted to represent the southward migration of foreland basin depozones (from distal foredeep and foredeep to distal wedge-top and proximal wedge-top, respectively) as the Zagros fold–thrust belt migrated progressively southward towards the Arabian foreland. This vertical succession bears a striking similarity to modern depositional environments and sedimentary deposits observed in the Zagros region today, where one passes from mainly braided rivers in the Zagros Mountains to meandering rivers close to the coast, to shallow marine clastic sediments along the northern part of the Persian Gulf and finally to carbonate ramp and sabkha deposits along the southeastern coast of the Persian Gulf. This link between the Neogene succession and the modern-day depositional environments strongly suggests that the major Neogene formations of the Zagros foreland basin are strongly diachronous (as shown recently by others) and have active modern-day equivalents. [ABSTRACT FROM AUTHOR]

The sediments from three stratigraphic levels in the Bababudan schist belt of Dharwar craton exhibit great diversity in major, trace and rare earth element (REE) geochemistry and thus interpreted to represent significant compositional variation in the source rocks. Detailed geological and geochemical studies have been carried out on clastic rocks constituting the Archaean Sargur supracrustals and the Bababudan belt of Dharwar craton (DC), southern India for understanding the geochemical characteristics and to define the Archaean-Proterozoic Boundary (APB/QPC) in southern India. There is significant contrast in the geochemical signatures for the sediments from these stratigraphic levles. The Sargur enclave population is characterised by slight LREE enrichment with (La/Sm)N ranging from 1.45 to 3.58, almost flat HREE with (Gd/Yb)N ranging from 0.65 to 1.29 with Eu/Eu* ranging from 0.49 to 0.91 suggesting mafic-ultramafic source rocks in the provenance. On the other hand, the Post QPC (PQPC) rocks are characterised by LREE enrichment with (La/Sm)N ranging from 2.66 to 7.07, nearly flat HREE with (Gd/Yb)N ranging from 0.58 to 0.95 and significant depletion of Eu with Eu/Eu* ranging from 0.34 to 0.85, indicating felsic province in the source area. The conglomerates and quartzites representing the QPC are showing mixed nature of these, reflecting the transitional character in depositional environment. Increase in abundance of REE, K2O/Na2O, Th/Sc, La/Sc, Th/U, Hf/Ta and Zr/Y ratios are characteristic of the QPC. The PQPC sediments are enriched in Th, U and HFSE like Hf, Nb, Zr and Y, and depleted in Co and Eu than their older counterparts. These geochemical signatures signify the dominance of mafic-ultramafic rocks in the source area for Sargur rocks and the existence of granite-granodiorite for PQPC clastics. Thus, the unconformity related oligomictic quartz pebble conglomerates (QPC) and quartzites at the base of Bababudan Group resembling the QPC of Witswaterand, South Africa signifies that a stable continental crust had already developed in southern India prior to ∼3.0Ga. [ABSTRACT FROM AUTHOR]

The clastic Horlick Formation contains an ichnofauna of 28 ichnotaxa dominated by burrowers. These are a mixture of simple vertical forms (Skolithos linearis, S. magnus, Bergaueria cf. langi, Rosselia socialis, Monocraterion isp.), U or arc-like forms (Diplocraterion parallelum, Arenicolites types A and B, Catenarichnus antarcticus, C. isp., aff. Lanicoidichna isp.), and complex, vertical spiral structures (Asterosoma isp., Spirophyton isp.). Horizontal burrows include Ancorichnus cf. capronus, Palaeophycus tubularis, and Psammichnites devonicus isp. nov. Surface traces comprise Haplotichnus isp., Cruziana problematica, C. rhenana, Rusophycus aff. carbonarius, R. isp., Protovirgularia rugosa, Lockeia ornata and cubichnia indet., while trackways include Diplichnites gouldi, D. isp., Maculichna? isp. and large imprints. The Horlick Formation (maximum 56 m) records an early Devonian transgression onto a deeply weathered land area that lay in the direction of Marie Byrd Land, spreading from the South Africa sector of Gondwana. Analysis of the trace fossils confirms their formation in near-shore to intertidal environments, with some ichnotaxa living close to the marine/fluvial boundary (e.g., Spirophyton, aff. Lanicoidichna, Cruziana problematica, Rusophycus aff. carbonarius, Maculichna?). The ichnofauna probably comprised a variety of marine suspension and deposit-feeding worms, shallow burrowing molluscs (bivalves and possibly bellerophontids) and several different types of arthropods, including trilobites. [ABSTRACT FROM AUTHOR]

We propose a model that explains the acid–base surface properties of clastic sediments from two Argentinean reservoir lakes. The model uses potentiometric titration data sets and fixed parameters such as the apparent stability constants and reaction stoichiometries of acid–base equilibriums involving known mineral phases. The model considers that sediments act as a set of independent sorption surfaces, such as organic matter, clay silicate, and iron (hydr)oxides, thus the acid–base equilibrium and the correspondent protolytic constants are represented by a humic acid, a Na-illite, and a poor crystalline Fe-hydr(oxide). In agreement with experimental data, the model predicts that all sediment samples show a similar charging behavior, increasing the negative charge as the pH increases. The net charge of sediments is controlled by the presence of negatively charged minerals and/or organic matter coatings. This reveals the great influence of clays and organic matter functional groups on the acid–base surface properties of sediments, and consequently on the surface reactivity toward contaminant transport. [ABSTRACT FROM AUTHOR]

Spring waters from alpine karst aquifers are important drinking water resources. To investigate in situ heterotrophic prokaryotic production and its controlling factors, two different alpine karst springs were studied over two annual cycles. Heterotrophic production in spring water, as determined by [3H]leucine incorporation, was extremely low ranging from 0.06 to 6.83 pmol C L−1 h−1 (DKAS1, dolomitic-karst-spring) and from 0.50 to 75.6 pmol C L−1 h−1 (LKAS2, limestone-karst-spring). Microautoradiography combined with catalyzed reporter deposition-FISH showed that only about 7% of the picoplankton community took up [3H]leucine, resulting in generation times of 3–684 days. Principal component analysis, applying hydrological, chemical and biological parameters demonstrated that planktonic heterotrophic production in LKAS2 was governed by the respective hydrological conditions, whereas variations in DKAS1 changed seemingly independent from discharge. Measurements in sediments recovered from LKAS2, DKAS1 and similar alpine karst aquifers ( n=12) revealed a 106-fold higher heterotrophic production (average 19 μmol C dm−3 h−1) with significantly lower generation times as compared with the planktonic fraction, highlighting the potential of surface-associated communities to add to self-purification processes. Estimates of the microbially mediated CO2 in this compartment indicated a possible contribution to karstification. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study is to recognize the basic clastic rock types on the basis of Hounsfield Units (HUs) by using statistical methods (hypothesis tests, distribution fitting, and confidence intervals). How does this recognition depend on depositional history of samples tested? Does the numerical pattern of HUs obtained from small-scale analyzing of some particular sedimentary structures coincide to the textural expectations of those sedimentary structures? Are the HU values provided by the CT measurements capable of evidencing micro-cycles belonging to a particular depositional history? For testing the numerical recognition, we analyze macroscopically homogeneous argillaceous marl, siltstone and fine sandstone samples with similar depositional background, age, and degree of diagenesis. The preliminary research shows that the Hounsfield Units can identify different sedimentary rocks considerably well. There are significant differences among the confidence intervals belonging to the different rock types. However, there also have been some slight overlaps among them. For analyzing the effects of the depositional processes in case of a particular rock type, samples from channel sandstone, distributary mouth-bar, massive (structureless) sandstone from a delta-fed turbidity fan, and channel sandstone with traction carpet origin from a delta-fed turbidity fan (all coming from Pannonian basin filling series) are used. The results prove again the significant differences in the terms of both confidence intervals and distribution-types; however, some overlapping also occurs. [Copyright &y& Elsevier]

Abstract: The influence of heterogeneous sediment properties on coastal processes is commonly underestimated due to the difficulty in characterizing and quantifying these types of sediments. Careful examination of previous research reveals that not only is sediment heterogeneity significant in terms of its impact on coastal processes, but that heterogeneous sedimentary environments comprise the majority of the world''s coasts. Using geologic and oceanographic field descriptions as a guide, we define sediment heterogeneity to include mixed grain sizes or types, spatial diversity in sediment properties and bedforms, and/or rapidly changing sediment characteristics. We categorize the dominant heterogeneous environments as 1) gravel-sand coasts, 2) sorted bedform fields, 3) sand-ridge fields, 4) cheniers, 5) mud transgressed coasts, 6) mixed tidal flats, and 7) graded foreshores and surf zones. We also specifically tabulate numerical ranges of sediment heterogeneity within each category. These categorizations exemplify the numerous natural patterns of important sediment variability and suggest that environmental characterizations that generalize complexity in terms of simplified descriptions, such as median grain size, are insufficient to describe the influence of many coastal sediments. [Copyright &y& Elsevier]

A petrographic study of 157 samples from the Early to Middle Eocene deep-marine sandy systems, Ainsa–Jaca basin, Spanish Pyrenees, shows that each system has a characteristic petrofacies. Three main petrofacies are recognized. Petrofacies 1 sandstones comprise mainly siliciclastic grains (≥80%), subordinate terrigenous carbonate grains and negligible intrabasinal grains. Petrofacies 2 hybrid arenites are characterized by significant amounts (≥10%) of intrabasinal carbonate grains. Petrofacies 3 calcilithites contain relatively abundant (≥10%) extrabasinal carbonate grains. On the basis of these petrofacies, a revised correlation of the sandy systems is proposed between the more proximal Ainsa basin, and the more distal Jaca basin sediments, now separated by the Boltaña anticline, across which it is impossible to actually trace out individual beds or sandstone packages between both basins. The arenite composition in the Ainsa and Jaca basins is interpreted as being controlled mainly by synsedimentary tectonic processes that led to changes in sediment sources during basin evolution. [ABSTRACT FROM AUTHOR]

Abstract: Amalgamated, fluvial sheet sandstones in the stratigraphic record are often interpreted as the deposits of braided rivers. Alluvial sequence stratigraphic models show these sheet sandstones overlying sequence boundaries and deposited during low rates of base level rise and fall. Since sequence stratigraphic models rely on the balance between creation/destruction of accommodation and sediment supply, is the sheet-like nature of these units controlled by channel style, by aggradation rates tied to base level changes or a combination of both? The lower member of the Castlegate Formation in the Book Cliffs of eastern Utah, U.S.A., was selected to answer these questions regarding the origin and architecture of amalgamated sheet sandstones. The lower Castlegate is 60 m thick and is underlain by a regional sequence boundary. Delineation of the alluvial architecture utilized a combination of outcrop photography, measured sections, and paleochannel dimension estimation at two outcrops in the type area. Architectural components within the outcrops were defined and include 1) basal, thalweg-fill units, 2) inclined sandy or heterolithic barform deposits, and 3) overbank siltstone and mudstone. Thalweg-fill units represent deposition in the topographically lowest part of the channel and are preferentially preserved. Thalweg units exist as single units or as a composite of multiple thalweg units. Overlying thalweg units, inclined barform deposits are in places preserved and genetically linked to an underlying thalweg-fill unit. Bar accretion directions, when combined with paleocurrent indicators, show that lateral, downstream and upstream accretion all occur in the lower Castlegate. Overbank deposits are rarely preserved, but where present they typically overlie bar deposits. The architectural components stack to form a threefold, cyclic hierarchy of 1) channel-bar systems (2–12 m thick), 2) channel belts (2–16 m thick), and 3) stacked channel-belt complexes (17–40 m thick). Complete channel-bar systems are rarely preserved and occur locally as a succession of multiple, stacked thalweg-fill units. The lack of barforms within a composite thalweg unit suggests that channel migration is the dominant process controlling preservation within channel-bar systems, possibly associated with a component of local avulsion. Channel belts are composed of stacked channel-bar systems capped by a barform. The barform is preserved due to a regional avulsion moving the active channel to another location within the floodplain, isolating it from potential reworking. Stacked channel-belt complexes are characterized by alternations of thalweg-dominated and barform-dominated channel belts. The mechanism responsible for deposition at the stacked channel-belt complex scale may be creation/destruction of accommodation associated with base level changes. Paleochannel reconstructions show that channel flow depths using bar and underlying thalweg thickness were up to 7.6 m. Channel depth estimates utilizing a cross-bed set thickness of 26 cm averaged 4.6–7.7 m. These values were used to calculate channel widths which were estimated at 143–365 m up to a maximum of approximately 1 km. Regional paleoflow within the lower Castlegate was dominantly southeast directed. The architectural components, paleochannel characteristics, and paleocurrent data suggest the lower Castlegate member was deposited in low to intermediate-sinuosity rivers influenced by autocyclic processes at smaller scales and allocyclic processes at the larger outcrop scale. [Copyright &y& Elsevier]