Devonian

Only a small number of wells has been drilled deep enough to reach the Devonian and/or Lower Carboniferous in the Netherlands. These wells are located on the northern flank of the London-Brabant Massif and on the Mid North Sea High.
The available knowledge only permits a lithostratigraphical subdivision which is partly informal. Additional data on the Devonian series were gathered from released British offshore wells. Discussions with Mr. D. Cameron of the British Geological Survey and Mr. M. Dusar of the Belgian Geological Survey have proved very informative. Various lithostratigraphic units from the UK side have been adopted for the Netherlands.
General information on the biozonation of the Upper Devonian can be found in Bless (1986) .

Geological history
After the Caledonian orogeny, the Devonian palaeogeo-graphy in northwestern Europe consisted of an Old Red Sandstone continent in the North Sea area, the Nether-lands and North-West Germany, and a marine trough south of this vast land mass (Rhenohercynian Basin; Ziegler (1990) . A17-01 (see pdf) reached the plutonic Caledonian basement on the Elbow Spit High, consisting there of an altered biotite monzo-granite with a minimum radiometric age of 346 ± 7 Ma Frost (1981) . Well O18-01 (drilled by Placid International Oil, Ltd.; not yet released) reached final depth in dark, turbiditic claystones and sandy claystones of Late Silurian age.
In the course of the Devonian the sea transgressed from south to north across the eastern part of the London-Brabant Massif area. The sea even extended northwards into the central North Sea area (Givetian carbonates and evaporites in the Auk and Argyll fields) during the Middle Devonian, apparently an epoch of world-wide rise in sea level Ziegler (1990) .
During the Late Devonian, the sea retreated from the North Sea area. Subsequently fluvial sands and claystones, mainly in a red-bed facies were deposited (Old Red Group). Locally, in the area of the Elbow Spit High, acid volcanism occurred (Rhyolite Member). Marine conditions persisted in the eastern part of the London-Brabant Massif area, resulting in the deposition of claystones (Bollen claystone). During a period of falling sea level at the close of the Devonian, a general break in deposition occurred. However, locally, regressive clastics and carbonates (e.g. the Bosscheveld formation) were deposited and preserved. Further south and east, sandstones (e.g. the Condroz Sandstone) were deposited by longshore currents during the late Famennian in the sea that bord-ered the Old Red continent and the (partially) emergent London-Brabant Massif Paproth (1986)
Regional correlation Regional lithostratigraphic correlation chart of the Devonian and Carboniferous for the Netherlands and neighbouring countries Regional lithostratigraphic correlation chart of the Devonian and Carboniferous for the Netherlands and neighbouring countries
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Chrono-stratigraphy Devonian litho-chronostratigraphic chart Devonian litho-chronostratigraphic chart
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References See References Devonian and Lower Carboniferous

Van Adrichem Boogaert, H.A. & Kouwe, W.F.P., 1993-1997. [Stratigraphic unit]. In: Stratigraphic Nomenclature of the Netherlands.
Retrieved [Datum] from [url].