Sediment-petrological study supporting the presence of the Kasterlee Formation in the Heist-op-den-Berg and Beerzel hills, southern Antwerp Campine, Belgium

The precise stratigraphic position of the sediments in the Heist-op-den-Berg and Beerzel hills has been under debate for a long time. According to the geological map of Flanders, these deposits are included in the Diest Formation. Reference data for the Diest and Kasterlee Formations are defined and compared to new sediment-petrological data from samples collected in the Heist-op-den-Berg and Beerzel area. This comparative study indicates that the sediments are similar to the Kasterlee Formation. Additionally, a gravel bed observed at the base of the deposits at the Heist-op-den-Berg and Beerzel hills is similar to the basal gravel of the Kasterlee Formation at Olen. The Kasterlee Formation at Heist-op-den-Berg and Beerzel is subdivided into three members. The lithofacies of the lowermost member is comparable to the Diest Formation and is explained through significant reworking. The occurrence of the Kasterlee Formation in the study area implies the formation of a bay or estuary in the late Miocene sea extending towards the south. The curvature in the present base of the Kasterlee Formation and the considerable thinning of the Diest Formation to the south indicates ongoing subsidence of the Campine basin and uplift of the Caledonian Brabant Massif during the late Miocene and Pliocene

A review of the lower and middle Miocene of northern Belgium

The stratigraphy, sedimentology and paleogeography of the lower and middle Miocene Berchem and Bolderberg Formations from northern Belgium have been extensively studied during the last decades, a.o. in the framework of doctoral research, as parts of subsurface mapping and interregional geological correlation initiatives by governmental organizations. The last formal stratigraphical revision on formation level, however, almost dates from two decades ago, notwithstanding the fact that a wealth of new data has become available. A compilation and assessment of the stratigraphical data of the lower and middle Miocene has been carried out and a refined stratigraphical framework-based on dinoflagellate cyst stratigraphy-is presented. Recommendations for the National Commission for Stratigraphy of Belgium are proposed. A new member, the Molenbeersel member, is proposed for the glauconite-bearing silts and fine sands in the upper part of the Bolderberg Fonnation in the Roer Valley Graben.Rhine during the late Tortonian

The Diest Formation : a review of insights from the last decades

Research conducted since the 1960s on the upper Miocene Diest Formation in NE Belgium is reviewed and integrated. Their lithology unites the deposits of the glauconiferous Diest Sand in one formation, though biozones and internal sedimentary structures strongly suggest the formation may agglomerate the deposits of two separate, successive sedimentary cycles. The lowermost cycle is thought to have deposited the "Hageland Diest sand" during the early or middle Tortonian. It contains the Diest Sand in the main outcrop area in Hageland, Zuiderkempen and central Limburg, and probably also the Deurne Member near the city of Antwerpen. It furthermore includes the lower part of the Dessel Member in the central Kempen and in the Belgian part of the Roer Valley Graben (RVG). The Hageland Diest cycle represents the infill of a large tidal inlet tributary to the southern North Sea bight, then situated over the southern Netherlands and the Lower Rhine embayment. The Hageland Diest sand has the composition of a marine deposit, yet the confined area of occurrence and the presence of tens of metres deep incisions at the base, set it apart. The confinement of the embayment, strong tides and a steady supply of coastal-marine sand arc invoked as the main driving forces that resulted in the distinctive geometry and internal architecture of the unit. The upper cycle is associated with the "Kempen Diest sand", which is found in the subsurface of the RVG and the Noorderkempen. It has a late Tortonian to earliest Messinian age with progressively younger ages occurring to the NW. It encompasses the upper part of the Dessel Member and the overlying, coarser Diest Sand, and correlates to most or all of the thickly developed Diessen Formation in The Netherlands. It is the deposit of a prograding marine delta, containing both marine components and continental components fed by the palaeo-Meuse/Rhine river mouths. Accommodation space kept increasing during deposition, due to subsidence of the deposition area, especially inside the RVG but also in the Noorderkempen. Although there is a fair consensus on the above, many concrete points about the geometry and depositional history of the Diest Formation and even a definitive decision on its single or dual character remain to be sorted out. In addition, this review excludes the Flemish Hills sand and the Gruitrode Member from the Diest Formation

The implications of K-Ar glauconite dating of the Diest Formation on the paleogeography of the Upper Miocene in Belgium

The glauconite-rich Diest Formation in central and north Belgium contains sands in the Campine subsurface and the hilly Hageland area that can be distinguished from each other. The Hageland Diest Sands member contains no stratigraphically relevant fossils while in the Campine subsurface dinoflagellate cysts are common and show a stratigraphic range covering the entire Tortonian stage. K-Ar dates were determined for glauconite from 13 selected samples spread over both areas. A glauconite date corresponding to the earliest Tortonian indicates newly formed glauconite was incorporated into a greensand at the base of the Diest Formation in the central Campine area. All other dates point at reworked glauconite and can be organized in two groups, one reflecting a Burdigalian age and another reflecting a Langhian age. These data and the thickness and glauconite content of the Diest Formation imply massive reworking of older Miocene deposits. The paleogeographic implications of these data lead to the tentative recognition of two Tortonian sedimentary sequences. An older one corresponding to dinoflagellate biochron DN8 comprises the Deurne Member, part of the Dessel Member, the Hageland Diest member, the eastern Campine Diest member and some basal sands of the Diest Formation in the central Campine. A younger sequence corresponding to dinoilagellate biochrons DN9 and 10 was strongly influenced by the prograding proto-Rhine delta front in the Roer Valley Graben to the northeast. The subsiding Campine basin was filled from east to west during this second cycle

The Kasterlee Formation and its relation with the Diest and Mol Formations in the Belgian Campine

Stratigraphic analysis of cored and geophysically logged boreholes in the Kasterlee-Geel-Retie-Mol-Dessel area of the Belgian Campine has established the presence of two lithostratigraphic units between the classical Diest and Mol Formations, geometrically related to the type Kasterlee Sand occurring west of the Kasterlee village and the study area. A lower 'clayey Kasterlee' unit, equivalent to the lithology occurring at the top of the Beerzel and Heist-op-den-Berg hills, systematically occurs to the east of the Kasterlee village. An overlying unit has a pale colour making it lithostratigraphically comparable to Mol Sand although its fine grain size, traces of glauconite and geometrical position have traditionally led stratigraphers to consider it as a lateral variety of the type Kasterlee Sand; it has been named the 'lower Mol' or 'Kasterlee-sensu-Gulinck' unit in this study. In the present analysis, the greenish glauconitic Kasterlee Sand in its hilly stratotype area evolves eastwards into the lower 'clayey Kasterlee' unit and possibly also into an overlying 'lower Mol' or `Kasterlee-sensu-Gulinck' unit, although it is equally possible that the latter unit has an erosive contact and therefore is stratigraphically slightly younger than the type Kasterlee Sand west of the Kasterlee village. A lateral extension of this detailed stratigraphic succession into the faulted one of east Limburg is proposed

The upper Miocene Deurne Member of the Diest Formation revisited : unexpected results from the study of a large temporary outcrop near Antwerp International Airport, Belgium

A 5.50 m thick interval of fossiliferous intensely bioturbated heterogenous glauconiferous sand of the upper Miocene Diest Formation is documented from a very large temporary outcrop just southeast of Antwerp International Airport (northern Belgium), allowing to observe lateral variations over several hundreds of meters and to collect many vertebrate and invertebrate fossils. This paper documents observations on lithology, sedimentary and post-sedimentary structures, and discusses the results of the multi-proxy analyses of the sediment (granulometry, glauconite content, clay mineralogy, Fe content and Fe3+/Fe2+ ratios), the interpretation of the trace fossil assemblage and the sedimentary structures as well as of the large-scale samplings of micro-, meso- and macrofossils. We evidence that the Diest Formation in the Antwerp area consists of two different lithological entities, and that this twofold character can be extrapolated to all previously recorded Deurne Member outcrops. A revised lithostratigraphic scheme for the Diest Formation in the Antwerp area is proposed, with the new Borsbeek member at the base and a redefmed Deurne Member at the top

Neogene and Quaternary clay minerals in the southern North Sea

In this work it was demonstrated how the systematic quantitative analysis of clay minerals yields a better understanding of specific geologicaland stratigraphical issues. In the first part, a reliable and accurate method for the X-ray diffraction analysis of clay minerals, and glauconite minerals in particular, was established. Especially the decomposition and separate quantification of the 060-region in random oriented powder diffraction patterns was found a powerful tool for the characterization of glauconite-bearing sediments. It was shown that pelletal glauconite is able to disintegrate to clay-sized glauconite during intensive preparation procedures. Nevertheless, the large majority, at least 80%,nbsp;of clay-sized glauconite in Neogene deposits in Belgium is introduced in the sediment by natural processes instead of artificially introduced during preparation procedures. To minimize contaminations, the clay mineralogy of pelletal glauconite-bearing sediments is systematically studied on size fractionslt;32µm, hereby isolating the large majority of pelletal glauconite, present in size fractionsgt;32nbsp; In the second part, quantitative clay and glauconite mineralogy was used as a lithostratigraphical characterization tool in the Neogene strata of the Campine basin in Belgium. In general terms, lithostratigraphy attempts to subdivide geological layers into packages which can be recognized and correlated in different locations. The most straight-forward method is to study the macroscopic lithology which is a clear, well-visible parameter prone to little subjectivity. In the Neogene deposits, such anapproach yields the recognition of bulk litho-units but seldom allows to define the exact boundary between different units. Geophysical well logs characterise vertical successions of sediments in a continuous way and also sampling and subsequent analyses can attempt to define exact lithostratigraphical limits. In this work, mineralogy and clay mineralogy are used for this purpose. It was demonstrated for the Neogene in Belgium that clay mineralogy allows (1) to unravel a more concise and detailed stratigraphic positioning, (2) for robust correlations between boreholes and, (3) to define reliably boundaries between differentformations and subunits. A major conclusion of this work is that theinvestigated Neogene Formations are very heterogeneous in lithological,mineralogical and sediment petrological characteristics. The oldest Neogene deposits of the Campine basin are those of the Berchem and Bolderberg Formation. It was shown that the subdivision of the Berchem Fm in theEdegem, Kiel and Antwerp Members is strictly based on the occurrence, or absence, of fossil assemblages, as no distinction can be made based onmineralogy or clay mineralogy only. The smectite-rich clay mineralogy of the Berchem Fm is also found in the Houthalen and Genk Members of the Bolderberg Formation. Pelletal glauconite is less abundant in the Houthalen Member compared to the different Berchem Members. Clay-sized glauconite in both Berchem and Houthalen consists of mainly higher-expandable glauconite-smectite. The Deurne and Dessel Members of the Diest Formation have almost identical clay mineralogical and sediment petrological characteristics compared to those of the Berchem and the marine Bolderberg Formation indicating important reworking. The Dessel Member was interpreted to be more than 30m thick in the Dessel area consisting of acalcareous lower Dessel part and a non-calcareous but also relatively fine-grained upper Dessel part. Pelletal glauconite is less abundant in the Dessel Member compared to the Berchem Formation of the Diest sand member. A major break in mineralogy and sediment petrology is observed in the Diest sand member, with the introduction of coarse clastics, and a glauconite-smectite dominated clay mineralogy in the Diest sand member. Four different litho-units were recognized in the Diest sand member, namedDiest D1-D4, of which the lowermost D1 unit is the most extensive unit composed of the coarse, loose, typical “Diest sand” with ca. 40% pelletal glauconite. Only in the western part of the basin, this unit is much thinner and is gradually replaced by a clayey and pelletal glauconite-poor facies, the Diest D2 and D3 units. At the top of the Diest Formation, the Diest D4 unit is present as a ca. 15m-thick deposit having a weathered origin, as indicated by the presence of Fe-vermiculite and kaolinite-expandable minerals. This unit was however not found in the southern part, such as in outcrops in Olen, Heist or the Hageland area where the Diest D1 unit forms the top of the Formation. The analyses of the Diest Formation occurrence in the Hageland reveal no strong arguments todistinguish it from the Diest D1 unit in the Campine based on the investigated mineralogical, clay mineralogical and sediment petrological parameters. The top Flemish hill deposits, traditionally attributed to the Diest Formation, are kaolinite- and illite-rich and are thus mineralogically significantly different from the Diest Fm deposits in the Hageland area. At the base of the Kasterlee Formation, a transition zone is found. Relatively high amounts of Fe-vermiculite, siderite, plagioclase, chlorite, pelletal glauconite, typical for the top Diest Formation, gradually transition into typical Kasterlee Fm sediment properties which are pelletal glauconitelt;5%, fine-grained and well-sorted size distribution, a glauconite-smectite dominated clay mineralogy, higher muscovite contents and only traces or even the complete absencenbsp;of chlorite, siderite, plagioclase and Fe-vermiculite. This transition zone marks the gradually decreasing influence of reworked Diest material at the base of the Kasterlee Formation. This transition zone has a thickness of 2m but up to 7m was found in the Rees borehole where it comprises the entire Kasterlee Formation. In the Dessel-Mol area, the transition zone iscovered by a sand facies which is frequently intercalated with clay laminae which disappear towards the top of the Formation. The top of the Kasterlee Fm and the boundary with the Pliocene Mol Fm is interpreted whenever the glauconite-smectite-dominated clay mineralogy of the Kasterlee Formation drastically changes to a kaolinite-dominated clay mineralogy of the Mol Fm. Muscovite contents can be significantly lower in the Mol Formation, which at its base is characterized by a relatively clay-rich zone. In the Poederlee Formation, different types of clay mineralogical assemblages were found. At the base, reworked Kasterlee materialwas observed in Lichtaart. New, smectite-rich Poederlee sediment was found in outcropping Poederlee deposits. In the Fe-sandstone facies of thePoederlee Formation, Fe-vermiculite and kaolinite-expandable indicate intensive weathering. This weathering also affected pelletal glauconite, of which the mineralogical composition consists of not only glauconite-smectite but also of Fe-vermiculite. It can be concluded that clay minerals in the investigated Neogene deposits origin from several sources: 1)nbsp;nbsp; Marine detrital clay is mainly transported from the northern North Sea and typically results in smectite-rich clay assemblages during the Miocene (e.g. Berchem Fm, marine Bolderberg Fm) and also the Pliocene (Poederlee Fm). 2)nbsp;nbsp; Clay-sized glauconite-smectite has no detrital origin but instead is locally derived from pelletal glauconite abrasion or even complete disintegration upon energetic transport. Clay-sized glauconite production can be the dominant clay supplier whenever detrital, marine- or land-derived, clay supply is insignificant, such as in the Diest D1 sand unit. 3)nbsp;nbsp; Continentally-derived clays were encountered in the Opgrimbie facies of the BolderbergFm, the Mol Fm and in the top Flemish hill sand deposits. The clay composition of all of the former deposits consists dominantly of kaolinite and illite most likely originating from the Ardennes-Rhenish massif in the south to southeast. This specific clay mineral assemblage is consequently also discharged by the Rhine delta in the east of the Campine basin. 4)nbsp;nbsp; It seems typical from the Neogene deposits that substantial amounts of the clay has a reworked origin, such as the Deurne and Dessel Member of the Diest Fm and the basal deposits of the Kasterlee and Poederlee Formations. Glauconite-smectite in the MolFormation is also considered as reworked. Intensive weathering of deposits also affects the clay mineralogy. Fe-vermiculite and kaolinite-expandable minerals were found in the Diest D4 unit, in the reworked part of the Kasterlee Formation and in the Poederlee Formation. Although in this research already a large amount of boreholes and samples were investigated, additional research on samples at strategically chosen locationsis required to solve some remaining issues. For instance, a better insight on the geographical distribution of the different defined Diest litho-units will yield further interpretations on the clay origin of the Diest clay-rich D2-D3 and weathered D4 units and the influence of the Rhinedelta in the eastern part of the Campine basin. Such a continued research should therefore also focus on the Diest Formation occurrence in the Netherlands, included in to the broad “Breda Formation”. Also for the Mol-Kasterlee-Diest stratigraphic differentiation, this research acts as a reconnaissance study for which a set of standard, mainly clay mineralogical, criteria were postulated to unambiguously interpret stratigraphic boundaries. The third part of this research concerns the provenance of recent mud deposits at the Belgian Continental Shelf. The geographical distribution of the typical BCS clay composition extends to the south untill Calais, to the north at least until the Rhine river mouth and also in the Scheldt estuary. It was also demonstrated that the typical BCS clay composition is present in early-Holocene tidal deposits of the coastal plain but it was also traced back in Weichsel (MIS-5d), Eemian (MIS-5e) and Saalian (MIS-7) deposits of dominantly fluvial origin. Analysis and recalculation of the present-day clay mineralogy of the different tributary rivers of the Scheldt system indicates that the Scheldt river system is the main clay source for the BCS muds. It has been proven that all other potential sources have a distinctly different clay mineralogy, which leaves only the Scheldt river system as provenance source. The present-day BCS clay compositionwas first introduced in the coastal plain when the paleo-Scheldt river system came into existence and discharged for the first time in westwarddirection, occupying the Flemish Valley. Most likely, this occurred around 400.000 years BP, during the Elsterian (~MIS12), after a proglacial breakthrough in the North Sea. Since this time , sediment transported by the river system was held nearby the coast during warm periods of high sea level. Depending on local hydrodynamics, the mudscould be deposited like in the U6 mudplate or eroded during periods of increased storm activity. During the latest glacial, most deposits are eroded and later sporadically reworked in coastal plain or shelf deposits, such as the mudplate U6 deposits. During the Holocene, the Scheldt changed its course and eventually discharged into the Westerschelde. It is believed that presently, the Scheldt river system does not activelydischarge fluvial mud into the North Sea, because of anthropogenic influence, but massively did before.nbsp;nbsp;nrpages: 292status: publishe

Natural clay-sized glauconite in the Neogene deposits of the Campine Basin (Belgium)

Natural clay-sized glauconite has the same mineralogical composition as sand-sized glauconite pellets but occurs in <2mm clay fractions. This particular glauconite habit has been described previously from soil environments resulting from pelletal weathering but is rarely reported in higher-energy sedimentary environments. In the present study, clay-sized glauconite was identified as a common constituent in transgressive Neogene glauconite pellet-rich deposits of the southern North Sea in Belgium. X-ray diffraction results revealed that the characteristics of the clay-sized glauconite are very similar to the associated glauconite pellets in sand deposits. Both glauconite types consisted of two glauconite-smectite R1 phases with generally small percentages of expandable layers (<30%) with d 060 values ranging between 1.513 Å and 1.519 Å. Clay-sized glauconite was not neoformed but formed by the disintegration of sand-sized glauconite pellets which were abraded or broken up during short-distance transport within the sedimentary basin or over the hinterland. Even in an environment where authigenic glauconite pellets occur, minimal transport over transgressive surfaces is sufficient to produce clay-sized glauconite.Furthermore, clay-sized glauconite can be eroded from marine deposits and subsequently resedimented in estuarine deposits. Clay-sized glauconite is, therefore, a proxy for the transport intensity of pelletal glauconite in energetic depositional environments and, moreover, indicates reworking in such deposits which lack pelletal glauconite.status: publishe

In situ synchrotron X-ray powder diffraction study of the early age hydration of cements blended with zeolitite and quartzite fi nes and water-reducing agent

A comparison was made between the early-age hydration of cements blended with micronized zeolitite and quartzite powders. The Portland cement replacement in the mixes was 30%, and the effect of introducing a superplasticiser to lower the required water to solid ratio was assessed. The cement pastes were hydrated at 40 °C and monitored in situ by time-resolved synchrotron X-ray powder diffraction combined with Rietveld quantitative phase analysis. The quantitative evolution of phase weight fractions showed that the addition of the zeolite tuff accelerated the hydration rate of the main C 3S cement component. Blending with the quartzite powder of similar fineness did not affect the C3S hydration rate. Reduction of the water to solid ratio by introduction of the superplasticiser had a retarding effect on the hydration of the zeolitite-blended cement over the early hydra- tion period up to 3 days. The AFt or ettringite reaction products, formed promptly after the addition of water to the mixtures, underwent a crystal structural modification over the induction period up to 4 to 6 hours of reaction. The con- tinuous contraction of the c-cell parameter and expansion of the a-cell parameter towards the ideal values for AFt or ettringite reflects the structural adaptation of the AFt to the changing availability of sulphate over the course of the first hours of hydration. The observed structural changes were less pronounced in the zeolitite blended cement. This is related to the dilution of the overall sulphate content in the blended cement and highlights the need to control and optimise sulphate additions in blended cements.publisher: Elsevier articletitle: In situ synchrotron X-ray powder diffraction study of the early age hydration of cements blended with zeolitite and quartzite fines and water-reducing agent journaltitle: Applied Clay Science articlelink: http://dx.doi.org/10.1016/j.clay.2012.12.002 content_type: article copyright: Copyright © 2012 Elsevier B.V. All rights reserved.status: publishe

Multi-scale analysis on the influence of moisture on the mechanical behavior of ferruginous sandstone

Moisture is known to decrease the mechanical properties of brittle construction materials. The present study focuses on the influence of moisture on the mechanical behavior of ferruginous sandstone in order to understand and quantify this effect. The investigated Diestian and Brusselian ferruginous sandstone have frequently been applied in monumental constructions and many of these monuments presently suffer from material degradation and, in some cases, stability concerns. Experimental analysis is performed on different levels, from micro to macro behavior, in order to obtain a more detailed picture of the acting processes. Therefore, a methodology is proposed which combines established as well as advanced experimental techniques, involving non-destructive testing for pre-classification of the sandstone's quality, mineralogical analysis and investigation of mechanical properties under dry and saturated conditions. It was observed that the decrease of mechanical properties, such as strength and stiffness, is more pronounced for lower-quality ferruginous sandstone. It was also found that water adsorption by the sandstone during acoustic emission-controlled creep tests shifts the specimen's behavior from meta-stable creep damage to accelerated failure. These observations were linked to the results of the mineralogical study, in which the consolidation degree and clay content were analyzed and to the results of the microfocus computed tomography which visualized the fracture progress on a micro scale. © 2013 Elsevier Ltd. All rights reserved.publisher: Elsevier articletitle: Multi-scale analysis on the influence of moisture on the mechanical behavior of ferruginous sandstone journaltitle: Construction and Building Materials articlelink: http://dx.doi.org/10.1016/j.conbuildmat.2013.12.024 content_type: article copyright: Copyright © 2013 Elsevier Ltd. All rights reserved.status: publishe