Diest Formation Research Articles

Cone Penetration Test characterization of middle and upper Miocene lithostratigraphic units near Antwerp International Airport

Recently published multidisciplinary studies discussed the glauconiferous sand units of the Berchem and Diest formations in large temporary outcrops near the Antwerp International Airport, east of the City of Antwerp, northern Belgium. At this location, the upper Miocene Diest Formation was subdivided into an upper Deurne Member and a lower, recently introduced, Borsbeek Member. In the current study, Cone Penetration Tests performed near the outcrops were used to geotechnically characterize the exposed units for regional correlations. For the Kiel and Antwerpen members of the middle Miocene Berchem Formation, the geotechnical expressions are nearly identical to those recently described further west in the City of Antwerp area. Contrary to the latter area, however, the upper part of the Antwerpen Member is missing, due to erosion below the Borsbeek Member. This erosion reached up to the level of a regionally occurring, compact shell bed in the middle of the Antwerpen Member, which may have protected the underlying sand from further erosion. Throughout the study area, the Borsbeek and Deurne members each show a consistent geotechnical facies, allowing for them to be distinguished on electric CPTs and thus for more reliable predictions of their areas of occurrence.

First fossil record of Mustelus aff. punctulatus Risso, 1826: new evidence for a smooth-hound shark population in the Late Miocene North Sea Basin

Mustelus is a problematic genus in palaeoichthyology. Due to the scarcity of fossil teeth, relative homogeneity in tooth morphology and the lack of published extant dentitions, the early history of smooth-hound sharks remains poorly understood. Recently, two teeth were collected in the Tortonian Deurne Member (Diest Formation) near Antwerp (Belgium). Surprisingly, a detailed SEM-based comparison with the extant North-Eastern Atlantic species (Mustelus mustelus, Mustelus asterias, Mustelus punctulatus) allowed assigning the fossil teeth to Mustelus aff. punctulatus. Today, this species is largely restricted to the Mediterranean and lies at the very base of the placental Mustelus clade evolution. Until now, this species remained unrecognized in the existing fossil record. By (re)evaluating isolated teeth from other upper Miocene localities in the southern North Sea Basin, the existence of a widely distributed population of Mustelus aff. punctulatus for the late Serravallian and the Tortonian can now be postulated. Thereafter, the species disappeared from the North Sea. Until today, no single record of Mustelus punctulatus is known from the Mediterranean predating the Messinian Salinity Crisis. Therefore, it is hypothesized that the current populations have their origin in southward migration from northern, Atlantic populations, and this probably after the “Zanclean Flooding”.

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 redefined Deurne Member at the top.

Reinterpretation of the Neogene sediments of the Bree Uplift, NE Belgium

The present geological map of the Flemish Region shows a small lens-shaped isolated outcrop of the Miocene Bolderberg, Diest and Kasterlee Formations, surrounded by younger formations, in an area that coincides with the tectonic Bree Uplift segment, on the southwestern border of the Roer Valley Graben in NE Limburg. The fault, bordering the segment at its SW side, had been interpreted to be tectonically active throughout the Neogene. Now, it is argued that an erroneous lithostratigraphic interpretation of the outcropping strata supported that view. Field observations of some of the outcrops and sampled drill holes show that the sediments do not belong to an Opitter member of the Bolderberg Formation, a Gruitrode Mill member of the Diest Formation and a Dorperberg member of the Kasterlee Formation, but most probably to the lower, latest Miocene or early Pliocene part of the Mol Formation and an unknown Pliocene marginal marine deposit not unlike and at about the stratigraphic position of the Poederlee Formation. That glauconiferous sand deposit, which has always been interpreted as consisting of two successive sedimentary cycles, is now accommodated in a single cycle, using the sedimentary model of deposition in a confined, backbarrier tidal basin subject to marine sand input and local stages of flow constriction and intraformational incision. Like already proposed by Rossa (1986) and Demyttenaere (1989), reprocessed seismic sections show only minor movements along the southwestern fault of the Bree Uplift since the Paleocene, and no inverse tectonic movements at all since the Middle Miocene.

Observations on the Pliocene sediments exposed at Antwerp International Airport (northern Belgium) constrain the stratigraphic position of the Broechem fauna

Detailed observations at a large temporary outcrop south of Antwerp International Airport (northern Belgium) reveal the complexity of a thin interval of fossil-rich Pliocene sediments found on top of the upper Miocene Diest Formation. Based on the lithological characteristics and mollusc faunas, several units were tentatively attributed to the Kattendijk Formation and the Luchtbal and Oorderen Members of the Lillo Formation. Concretions containing characteristic preserved molluscs dominated by large paired bivalves and that are informally known as the Broechem nodules were observed in situ between the Kattendijk Formation and Lillo Formation, and in reworked position in the base of the latter, indicating a late Early Pliocene age. The role of extensive reworking in the formation of Pliocene units is shown and implications for stratigraphic framework of Pliocene deposits from northern Belgium are discussed.

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 are 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.

Quantitative clay mineralogy as a tool for lithostratigraphy of Neogene Formations in Belgium: a reconnaissance study

Although the main stratigraphic frame of the Neogene in North Belgium is well established still several issues remain. This is in particular the case at the boundaries of lithostratigraphic units and where lateral facies have developed. Not only are more biostratigraphic data needed but also the commonly used geophysical well logging needs a better information on the precise influence of the variable mineralogy in the sediments. In particular glauconite, muscovite and clay mineralogy need a detailed analysis. Such an analysis is carried out on the Antwerp Member of the Berchem Formation, the Diest Formation, the Kasterlee Formation and the Mol Formation with particular emphasis on the boundary intervals between these units. Clay minerals, glauconite, feldspars and muscovite are analyzed. Interstratified glauconite/smectite appears to be common in the low abundant dispersed clay fraction of sand rich in glauconite pellets. Marine units generally consist of detrital smectite-rich assemblages while kaolinite becomes more abundant in units under more continental influence. The presence of Fe-rich vermiculite in a clayey top facies of the Diest Formation indicates the influx of soil material containing weathered glauconite. It is common to find that the basal sediments of a new unit contain the mineralogical heritage of the underlying unit. The clay mineral content has helped to differentiate between units, to locate the boundaries between units and to understand the reworking that occurred at the base of new stratigraphic units. The mineralogical information can also be used to interpret the natural radioactivity and resistivity signals in the borehole logs.

The architecture of the Kattendijk Formation and the implications on the early Pliocene depositional evolution of the southern margin of the North Sea Basin

An east-west correlation profile through the upper Neogene succession north of Antwerp, based on cone penetration tests, reveals the architecture of the lower Pliocene Kattendijk Formation. It shows a basal incision of the Kattendijk Formation down to 20 m in Miocene sands and locally even Lower Oligocene clays. The incision is part of a much larger gully system in the region at the base of the Kattendijk Formation. The strongest gully incision is observed along the western profile, and coincides with increases in the thickness of the Kattendijk Formation from its typical four to six meters thickness in the east towards a maximum of 15 m in the west. Correlations show that this additional thickness represents a separate sequence of the Kattendijk Formation that first filled the deepest part of the gully prior to being transgressed and covered by the second sequence deposited in a larger gully system. Both sequences of the Kattendijk Formation have basal transgressive layers, and are lithologically identical. Initial, deep incision at the base of the Kattendijk Formation might have been the result of the constriction of early Pliocene tidal currents that invaded and expanded fluvial or estuarine gullies that had developed during the latest Miocene sea-level low. A similar mechanism had been proposed for the development of late Miocene gully system at the base of the Diest Formation further southeast in northern Belgium. As the wider area was transgressed and covered by the second sequence of the Kattendijk Formation, flow constriction ended, currents weakened and gully incisions were reduced in size.

Dinoflagellate cyst stratigraphy and palaeoenvironment of the marginal marine Middle and Upper Miocene of the eastern Campine area, northern Belgium (southern North Sea Basin)

AbstractA stratigraphical and palaeoenvironmental analysis with organic‐walled palynomorphs of the Bolderberg and Diest formations provides new insights in the depositional history during Miocene times at the southern border of the North Sea Basin. The Neogene transgression invaded Belgium from a north–northwestern direction and fully marine sediments were deposited in the northern part of Belgium. The age and the palaeoenvironment of the deposits at the very border of the southern North Sea Basin remained till a few decades ago incomplete. The recovered dinoflagellate cysts, acritarchs and green algae from the Bolderberg Formation in the Wijshagen Borehole indicate a marginal marine depositional environment during late Burdigalian and Langhian times in the eastern Campine area, in contrast to the deeper marine conditions prevailing to the north–northwest. The relative dating of the Bolderberg Formation confirms that maximum flooding occurred during Langhian to early Serravallian times. Deposition apparently took place during the Middle Miocene Climatic Optimum, and ended when the climatic deterioration set in at around 14 Ma. A hiatus spanning ca. 2 Ma separates the Middle Miocene Bolderberg Formation from the Upper Miocene Diest Formation in the eastern Campine area at the border of the North Sea Basin. Copyright © 2007 John Wiley & Sons, Ltd.

The Upper Miocene of the southern North Sea Basin (northern Belgium): a palaeoenvironmental and stratigraphical reconstruction using dinoflagellate cysts

Organic-walled palynomorph assemblages from the Kasterlee Formation in northern Belgium provide new insights into the Late Miocene depositional history and palaeoenvironments of the southernmost North Sea Basin. Ranges of key dinoflagellate cysts constrain the unit between 7.5 and 5.32 Ma, that is, a latest Tortonian to Messinian age. The palynomorph assemblage is characterized, amongst others, by Geonettia clineae, an opportunistic species that thrives in mesotrophic, coastal embayments with a low sediment influx. This environmental setting is corroborated by the notable presence of Gramocysta verricula, a species with preference for shallow marine environments. The occurrence of species of the fresh water green alga Pediastrum indicates manifest river discharge in a near-shore environment or embayment. The coastal depositional environment mirrored by the palynomorphs of the Kasterlee Formation succeeds the distinct transgressive and fully marine environments of the underlying Diest Formation in the Campine area. The results from the palynological study, combined with lithological and geophysical data, show that both Upper Miocene formations are two distinct depositional cycles separated by an erosional or regressive phase. The upper boundary of the Kasterlee Formation is correlated with the Me2 sequence boundary at 5.73 Ma. The Kasterlee Formation is herein formally moved from the Lower Pliocene series to the Upper Miocene series. The coastal environment, probably characterized by a shoaling phase, recorded at the border of the southern North Sea Basin, matches the global record of regressive phases in Messinian sedimentary sequences, which are linked to cooling and increasing global ice volume.

Dinoflagellate cyst biostratigraphy of the Upper Miocene Deurne Sands (Diest Formation) of northern Belgium, southern North Sea Basin

AbstractDiverse and well‐preserved palynomorph assemblages recovered from the Deurne Sands, a local member of the Upper Miocene Diest Formation near Antwerp, allow the recognition of dinoflagellate cyst biozones defined in the North Atlantic realm (East Coast, USA) and the North Sea region (Nieder Ochtenhausen well, northern Germany). Based on the dinoflagellate cyst assemblages and the calcareous microfossils, the deposition of the Deurne Sands took place at some time during middle to late Tortonian (Late Miocene). These sands can be correlated biostratigraphically with the Dessel Sands in the Campine area of northern Belgium. This correlation demonstrates the existence of two separate and contemporary depositional areas in northern Belgium during early Late Miocene times. Copyright © 2002 John Wiley & Sons, Ltd.

New species of organic-walled dinoflagellates and acritarchs from the Upper Miocene Diest Formation, northern Belgium (southern North Sea Basin)

A palynological investigation of the shallow marine Diest Formation (Upper Miocene) in northern Belgium has revealed the presence of five previously undescribed dinoflagellate cyst species and one acritarch. A formal description and a preliminary assessment of the stratigraphical ranges of following species is given: Bitectatodinium? arborichiarum Louwye, sp. nov., Operculodinium antwerpensis Louwye, sp. nov., Batiacasphaera deheinzelinii Louwye, sp. nov., Cerebrocysta lagae Louwye, sp. nov., Barssidinium taxandrianum Louwye, sp. nov. and Palaeostomocystis globosa Louwye, sp. nov.

Dinoflagellate cyst stratigraphy and depositional history of Miocene and Lower Pliocene formations in northern Belgium (southern North Sea Basin)

The occurrence of organic-walled dinoflagellate cysts (dinocysts) in the Diest Formation, a largely decalcified succession with a poor fossil content, and in the adjacent strata of Lower Miocene and Lower Pliocene formations, allowed a biostratigraphic evaluation of these deposits and an assessment of the hiatus between the lithostratigraphic units. The Diest Formation was deposited during Tortonian – Messinian times. Dinocyst biozones defined in the North Sea region and the U.S.A. East Coast are recognised within the Diest Formation, although environmental factors seem to have influenced the presence of some key zonal species in the shallow-marine deposits of northern Belgium. The two members of the Diest Formation studied, i.e., the Dessel Sands and the Diest Sands, appear to be strongly diachronous. The depocentre was located in the Campine area during the early Tortonian and shifted to the area north of Antwerp during late Tortonian to Messinian times. The age assessment provides a correlation of the sequence boundaries of Haq et al. (1987) at the top of the Diest Formation with SB 5.5.

Dinoflagellate cysts of the shallow marine Neogene succession in the Kalmthout well, northern Belgium

The dinoflagellate cyst associations from the Neogene succession in the Kalmthout well allow a correlation with biozonations and key dinocyst events from the North Sea area and the eastcoast of the USA. The recovered cyst assemblages suggest that an Early Miocene (late Aquitanian – early Burdigalian) age can be attributed to the Berchem Formation, while the Diest Formation is of Late Miocene (late Tortonian – Messinian) age. The age of the Kattendijk Formation remains unclear. The Lillo Formation in the Kalmthout well is of Pliocene age and possibly not younger than early Late Pliocene.