Geologie En Mijnbouw 

About: Geologie En Mijnbouw is an academic journal published by Cambridge University Press. The journal publishes majorly in the area(s): Holocene & Pleistocene. It has an ISSN identifier of 0016-7746. It is also open access. Over the lifetime, 822 publications have been published receiving 18368 citations. The journal is also known as: Netherlands journal of geosciences & Geologie en mijnbouw.

Cretaceous oceanic anoxic events: causes and consequences

Abstract: Organic carbon-rich sediments are globally developed in pelagic sedimentary sequences of Aptian-Albian and Cenomanian-Turonian age. They formed in a variety of paleo-bathymetric settings including oceanic plateaus and basins, continental margins and shelf seas. The widespread nature of these deposits suggests that they were not strictly controlled by local basin geometry but were a product of ″Oceanic Anoxic Events″ . Interpretation of these events as the result of the interplay of two major geologic and climatic factors is given. The Late Cretaceous transgression which increased the area and volume of shallow epicontinental and marginal seas and was accompanied by an increase in the production of organic carbon; and the existence of an equable global climate which reduced the supply of cold oxygenated bottom water to the world ocean. This combination of climatic and hypsographic conditions favoured the formation of an expanded oxygen-minimum layer and where this intersected the sediment-water interface, organic carbon-rich deposits could be formed, these being records of ″Oceanic Anoxic Events″ .

Biostratigraphy of Cretaceous calcareous nannoplankton

Abstract: The stratigraphical distribution of selected species of calcareous nannoplankton from sections of Cretaceous deposits in Tunisia, France, The Netherlands, West Germany, Great Britain, Denmark, Turkey, Oman and New Jersey was studied. A number of Late Cretaceous lineages was recognised, on which a proposal for a revised zonation is based. Twenty-six zones are distinguished for the Cretaceous interval. First-order correlations between zones and Cretaceous stage-s(ratotypes are discussed, briefly. The Upper Cretaceous part of the proposed zonation has also been correlated with planktonic foraminiferal zones. One new genus and two new species' are described.

The eastern Mediterranean climate at times of sapropel formation: a review

Abstract: Sapropel formation in the eastern Mediterranean coincided closely with minima in the precession index. Such minima occur approximately every 21000 years. At such times perihelion falls within Northern Hemisphere summer. Minima in the precession index are characterized by intensified Indian Ocean (summer) SW monsoonal circulation, which enhanced discharge of the river Nile into the eastern Mediterranean. However, by compiling paleoclimatological data from the literature, the influence of the monsoon is shown to have reached only as far as the southern Sinai Desert. Therefore, it does not account for contemporary humid phases in the northern borderlands of the eastern Mediterranean, which seem to have been characterized mainly by increased summer precipitation. We argue that increased (summer) precipitation along the northern borderlands of the eastern Mediterranean, at times of sapropel formation, was probably due to increased activity of Mediterranean (summer) depressions. Forming predominantly in the western Mediterranean and tracking eastwards, such depressions tend to lower the excess of evaporation from the eastern Mediterranean relative to that from the western basin. Picking up additional moisture along their eastward path, such depressions also redistribute freshwater within the complex eastern Mediterranean water balance. The increase in runoff and the related flux of nutrients and continental organic matter that resulted from the increased precipitation on the northern borderlands of the eastern Mediterranean, at times of sapropel formation, presumably provided a substantial addition to that which entered the eastern Mediterranean via the Nile.

The Holocene evolution of the barrier and the back-barrier basins of Belgium and the Netherlands as a function of late Weichselian morphology, relative sea-level rise and sediment supply

Abstract: Flooding of the southern part of the North Sea occurred between 9000 and 8000 BP, when the rate of relative sea-level rise was on the order of 0.7 cm per year for the Dover Strait Region and 1.6 cm per year for the area north of the Frisian Islands, forcing the shoreline to recede rapidly. When relative sea-level rise decelerated after 7000 BP for the Belgian coast and 6000 BP for the central Netherlands coast, sediment supply by the tidal currents balanced the creation of accommodation space in the estuaries and other back-barrier basins. Consequently, the barrier started to stabilize, and the tidal basins and their inlets silted up. Between 5500 and 4500 BP, the Belgian coastal plain changed into a freshwater marsh with peat accumulation, and the same happened 500-1000 years later in the western provinces of the Netherlands. The E-W running barrier/back-barrier system of the Frisian Islands in the northern Netherlands stayed open until today, however, because of lower sediment supply. The period between 4000 and 2000 BP was relatively quiet due to the strong deceleration of the rate of sea-level rise; peat cushions developed behind the barriers, which were straightened by erosion of the headlands. Major and often catastrophic flooding occurred in the Middle Ages, when the estuaries in the southwestern part of the Netherlands formed. About 226 (± 15%) x 109 m3 sediment, mostly sand, is stored in the barriers and back-barrier basins of the Netherlands, 70% of which was deposited prior to 5000 BP. About 10% of the stored sediment is estimated to be of alluvial origin. Most of the sediment is derived by the erosion of the Pleistocene basement during recession of the barriers, but tide-induced cross-shore transport from the North Sea forms an additional source for the barriers and back-barriers of the west-facing coast of the Netherlands.

A sporomorph ecogroup model for the Northwest European Jurassic - Lower Cretaceousi: concepts and framework

Abstract: Based on recent vegetation distribution and an integration of macropalaeobotanical and palynological information, a palaeocommunity model is explored that may permit detailed interpretations of quantitative sporomorph distribution patterns in the Jurassic and Early Cretaceous of NW-Europe in terms of changes in palaeoenvironment (sea-level, climate). The conceptual model is based on the recognition of Sporomorph Ecogroups (SEGs) that reflect broad co-existing plant communities, viz. upland, lowland, river, pioneer, coastal, and tidally-influenced SEGs. In successive palynological assemblages, shifts in the relative abundance of SEGs are thought to be indicators of sea-level changes. Climatic changes may be recognised through significant shifts within the quantitative composition of individual SEGs.