Biostratigraphy and ecostratigraphy of Late Cretaceous deposits in the Kunrade area (South-Limburg, SE Netherlands)

The Late Cretaceous deposits in the Kunrade area in South-Limburg (SE Netherlands) differ from the classic outcrops around Maastricht in their lithofacies and fossil content. On the basis of biostratigraphic and ecostratigraphic data from 24 sections (2 boreholes and 22 outcrops), an ecostratigraphic subdivision into five ecozones is proposed. This ecozonation is correlated with sections at Valkenburg a/d Geul (Thermae Borehole), Maastricht (Kastanjelaan Borehole), Hoepertingen and Diet-Heur

Event-induced changes in Late Cretaceous to Early Paleocene ostracode assemblages of the SE Netherlands and NE Belgium

Late Cretaceous to Early Paleocene ostracode assemblages in the SE Netherlands and contiguous areas of Belgium underwent several event-induced changes in their qualitative and quantitative composition. The first change took place between the Early and Late Campanian and is marked by the appearance of several new taxa, many of which belong to Cytherelloidea and Bythoceratinae. The event causing this obvious diversification may have been either a deepening of the sea or a warm-up of the marine environment. The second important change during the mid-Late Maastrichtian seems related to the relaxation of regional inversion tectonics and a concomitant massive invasion of Tethyan elements. Finally, the third event at the Maastrichtian-Danian (Cretaceous-Tertiary) boundary is distinguished by a practically complete species turnover and the disappearance of eighty percent of the Late Maastrichtian ostracode genera from the area. However, at least some fifty percent of these genera survived elsewhere in the northern Tethys. This illustrates that the drastic change in the ostracode faunas of the SE Netherlands was caused by changes in the regional environment of NW Europe and not by a massive, global extinction event

Microfossils and depositional environment of late Dinantian carbonates at Heibaart (Northern Belgium)

The core intervals of five boreholes in the Dinantian carbonates of the Heibaart area in northern Belgium have been investigated on their microfossil contents and lithofacies. The foraminifers suggest an early Warnantian age. No conodonts have been recovered. Twenty-eight species of ostracodes are described, two of them being new : Bairdia robinsoni nov. sp. and Rectobairdia conili nov. sp. The carbonates consist of bioclastic wackestones, bioclastic-peloid grainstones and algal bindstones. The depositional environment varied from an open marine shelf lagoon in the earliest Warnantian (Cf 6a zone) to very shallow lagoons with a restricted water circulation in the Cf 6a - ß zone. The extreme large size of the ostracode species recovered from the Cf 6a - ß zone is not characteristic of the very shallow lagoon environment. Extremely large ostracodes have also been recognized in other carbonate facies of Dinantian age

Late Cretaceous sea level rise and inversion: their influence on the depositional environment between Aachen and Antwerp

Pluridisciplinary investigations on Upper Cretaceous (Santonian to Maastrichtian) in the Aachen-Antwerp area (NE Belgium, SE Netherlands and Aachen area of Federal Republic of Germany) have revealed the rather complex sedimentary history of the same. Correlations between different lithologies are based on bioclasts, foraminifera, ostracodes, belemnites and petrophysical borehole logs. Deposition was controlled by continuous sea level rise during the Santonian to late Upper Maastrichtian and by tectonic movements (inversion of subsidence since the Lower Campanian, relaxation of the inversion since the middle Upper Maastrichtian, differential warping of blocks to the south of the Rur Valley area notaby during the Upper Campanian to early Upper Maastrichtian).A major change in the fossil assemblages at the onset of the middle Upper Maastrichtian is noticed in the appearance of mediterranean elements, in a dramatic change in the quantitative composition of bioclast assemblages, and in a rather abrupt and pronounced diversification of most fossil groups. This change matches the beginning relaxation of the inversion in the Rur Valley area and it is interpreted as one of several regional, tectonically induced ecostratigraphical events

Repeated Tethyan influences in the Early Campanian to Middle Late Maastrichtian successions of Folx-Les-Caves and Orp-Le-Petit

A preliminary study of the macrofossils (belemnites in particular), benthic forams and ostracodes in the Late Cretaceous chalk deposits at Folx-les-Caves and Orp-le-Petit (eastern Brabant Massif, Belgium) suggests that the sequence at Folx-les-Caves is of early Campanian (post lingua/quadrata Zone) age. The «craie blanche» and the «tuffeau jaunâtre» at Orp-le-Petit were deposited during the late Campanian and middle late Maastrichtian, respectively.The sedimentation of these chalks under shallow to very shallow subtidal conditions was temporarily interrupted by periods of emergence (conglomerate at Folx-les-Caves; hardground at Orp-le-Petit).The fossil assemblages of the early Campanian and middle late Maastrichtian comprise several distinctive Tethyan elements amongst macrofauna, forams and ostracodes which are rare in or absent from the late Campanian to early late Maastrichtian in Belgium and the SE Netherlands. Possible causes of these repeated Tethyan incursions are discussed

The Hautes Fagnes area (NE Belgium) as a Monadnock during the Late Cretaceous

Morphologically, the Hautes Fagnes area (NE Belgium) is at present a regional high, rising some 100-150 m above the Ardennes plateau, which is slightly inclined to the NW (1°). Recently, a number of residual Late Cretaceous deposits in this area have been sampled in an attempt to reconstruct the gradual Campanian-Maastrichtian transgression onto the area, which acted as a monadnock during this period. Each succession starts with a basal conglomerate, which becomes progressively younger towards the summit of the Hautes Fagnes, indicating the step by step inundation of the area. The deposits have been analysed for bioclast assemblages, fish remains and phosphatised macrofauna, as well as for various microfossil groups, such as forams, ostracodes and sponge spicules. These allow a brief discussion of the paleoenvironment and age of these completely decalcified strata