Papers I've Read
From river valley to estuary: the evolution of the Rhine mouth in the early to middle Holocene (western Netherlands, Rhine-Meuse delta)
From river valley to estuary: the evolution of the Rhine mouth in the early to middle Holocene (western Netherlands, Rhine-Meuse delta)
Co-authored with K.M. Cohen, G.Hoffmann, A.J.F. van der Spek and E.Stouthamer, published in Netherlands Journal of Geosciences - Geologie en Mijnbouw 88 (1): 13-53
The aim of this paper is to reconstruct the evolution of the early to middle Holocene Rhine-Meuse river mouths in the western Netherlands and to
understand the observed spatial and temporal changes in facies. This is achieved by constructing three delta wide cross-sections using a newly
accumulated database with thousands of core descriptions and cone penetration test results, together with a large set of pollen/diatom analyses
and OSL/14C-dates. Most of the studied deposits accumulated in the fluvial-to-marine transition zone, a highly complex area due to the interaction
of terrestrial and marine processes. Understanding how the facies change within this zone, is necessary to make correct palaeogeographic
interpretations.
We find a well preserved early to middle Holocene coastal prism resting on lowstand valley floors. Aggradation started after 9 ka cal BP as a
result of rapid sea-level rise. Around 8 ka most parts of the study area were permanently flooded and under tidal influence. After 8 ka a bay-head
delta was formed near Delft, meaning that little sand could reach the North Sea. Several subsequent avulsions resulted in a shift from the
constantly retreating Rhine river mouth to the north. When after 6.5 ka the most northerly river course was formed (Oude Rijn), the central part
of the palaeovalley was quickly transgressed and transformed into a large tidal basin. Shortly before 6 ka retrogradation of the coastline halted
and tidal inlets began to close, marking the end of the early-middle Holocene transgression.
This paper describes the transition from a fluvial valley to an estuary in unprecedented detail and enables more precise palaeo-reconstructions,
evaluation of relative importance of fluvial and coastal processes in rapid transgressed river mouths, and more accurate sediment-budget
calculations. The described and well illustrated (changes in) facies are coupled to lithogenetic units. This will aid detailed
Like (4)Het Rijnmondgebied in het Vroeg Holoceen: inzichten uit een diepe put bij Blijdorp (Rotterdam)
Het Rijnmondgebied in het Vroeg Holoceen: inzichten uit een diepe put bij Blijdorp (Rotterdam)
Cohen, K.M., Hijma, M.P. (2008) Grondboor & Hamer 62(3/4) 64-71 (in Dutch; Special issue on the Geology of the Netherlands' coast. Translate title: Rhine mouth area in the Early Holocene: insights from a deep pit near Blijdorp (Rotterdam))
(Abstract in English)
A 21-m deep construction pit in Rotterdam allowed an opportunity to inspect the base of the the Holocene sequence in the Netherlands. The deposits showed a drowning fluvial and inland-dune landscape: fast sea-level rise changed that landscape into an estuarine sedimentary environment. This transition occured between 9 and 8 duizend years ago, was gradual but includes two events, about 8,400 years and 8000 yeasrs ago. These events are tentatively attributed to accellerated sea-level rise respectively run-out of the Storegga-tsunami (known to have occured from elsewhere in the world), if not extreme storm surges (leaving major impact in the southern North Sea only).
(Abstract in Dutch)
Een 21 m diepe bouwput in Rotterdam bood de gelegenheid de basis van het Holocene pakket te bekijken. De afzettingen lieten een verdrinkend rivier- en duinlandschap zien als gevolg van snelle zeespiegelstijging en een overgang naar estuariene condities. Deze overgang vond plaats tussen 9 en 8 duizend jaar geleden en verliep geleidelijk met twee versnellingen: één rond 8,400 jaar geleden als gevolg van een zeespiegelsprongetje en één rond 8,000 jaar geleden, mogelijk als gevolg van een zware storm of de uitrollende Storegga-tsunami.