Sedimentologie en stratigrafie van enkele pleistocene afzettingen in de Belgische kustvlakte
De Moor, G.; De Breuck, W. (1973). Sedimentologie en stratigrafie van enkele pleistocene afzettingen in de Belgische kustvlakte. Natuurwet. Tijdschr. 55(1-3): 3-96 In: Natuurwetenschappelijk Tijdschrift. L. Walschot/Natuur- en Geneeskundige Vennootschap: Gent. ISSN 0770-1748, more |  |
| Keywords | Coastal zone
Earth sciences > Geology > Sedimentology
Earth sciences > Geology > Stratigraphy
Geological time > Phanerozoic > Geological time > Cenozoic > Quaternary > Pleistocene
ANE, Belgium, Belgian Coast [Marine Regions]
Marine/Coastal |
| Abstract | The lithological homogeneous units of the Quaternary , which have been exposed in an excavation at Meetkerke (51°13'32" N, 3°09'43" E) near the limit of the coastal area, have been described in detail. The primary and secundary sedimentary structures have been carefully examined. The genetical and paleoclimatological interpretation of the lithological features and the interfaces has led to distinguish four lithostratigraphic units. These units do not always present a uniform lithotype but sometimes form a complex of syngenetical and synsedimentary facies. The chronostratigraphical interpretation is based upon paleoclimate indications, the hypsography of the marine deposits, and radiocarbon datings. The lowest unit, the formation of Meetkerke, is a tidal-flat deposit with sandy, loamy and clayey facies. The tabular sedimentation indicates a discontinuous transgressive trend. The aggradation has been interrupted by desiccation phases. The deposits contain zones with bivalves in living position and zones which have been intensely bioturbated. The overlying formation of Stalhille is formed by shell bearing sandy deposits of a beach barrier along a coast with a strong residual westward current. The fossils are partly penebiocoenotical, but for the largest part reworked from the underlying, even Tertiary strata. The formation of the Lage Moere is not very well developed at Meetkerke covering the preceding formation only locally. It is formed by sandy material which has been hydrocryostatically expulsed from a mollisol in the formation of Stalhille. The uppermost formation of Sint-Andries is composed of fine sands of niveoeolian and niveofluvial origin. During the Middle Holocene the Soil of Varsenare developed on its surface. The Subboreal peat of Nieuwmunster has been removed. The stratigraphic column shows an important gap between the formation of Stalhille and that of Sint-Andries. The formations of Meetkerke and Stalhille have been deposited during a period in which the sea stood at a high level. The presence of cryoturbations suggests a pre-Holocene, interstadial or interglacial, age. Since there is no sufficient evidence for an intra-Weichselian sea level that reached the present zero, the fossil content, the hypsography, and the paleoclimatic succession point to an Eemian age for both formations. Since this area has not been affected by tectonic movements the sea has reached the level of + 1 m Z.0. The geochronological interpretation does not agree with some of the radiocarbon datings on marine shells in living position of these formations. In the upper part the shells indicate an age of 21000 to 17000 BP., which is probably caused by contamination. The shells of the lower part on the contrary show ages which do not contradict the preceding interpretation. The formations of the Lage Moere and Sint-Andries are Weichselian periglacial deposits. There is no direct evidence for a more detailed stratigraphical identification although same indications exist for assuming a Late Weichselian age for the formation of Sint-Andries. The erosion surface of the Tertiary substratum cuts across the interface between Ypresian sand (Yd) and the base clay of the Paniselian (P1m). |
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