Institution
Geological Survey of Denmark and Greenland
Facility•Copenhagen, Denmark•
About: Geological Survey of Denmark and Greenland is a facility organization based out in Copenhagen, Denmark. It is known for research contribution in the topics: Greenland ice sheet & Ice sheet. The organization has 844 authors who have published 3152 publications receiving 104706 citations. The organization is also known as: Danmarks og Grønlands Geologiske Undersøgelse.
Topics: Greenland ice sheet, Ice sheet, Holocene, Glacier, Groundwater
Papers published on a yearly basis
Papers
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TL;DR: The Danish Mariager Fjord is normally anoxic but for two weeks in 1997, the water column became anoxic to the surface for a distance of 20 km as discussed by the authors.
77 citations
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TL;DR: In this article, the effect of layer silicate addition is most pronounced for palygorskite and smectite having the largest surface area and negative charges on the particle surfaces.
Abstract: Pozzolanic submicron-sized silica fume and the non-pozzolanic micron- and nano-sized layer silicates (clay minerals) kaolinite, smectite and palygorskite have been used as additives in Portland cement pastes and mortars. These layer silicates have different particle shape (needles and plates), surface charge, and size (micron and nano). The structure of the resulting cement pastes and mortars has been investigated by atomic force microscopy (AFM), helium porosimetry, nitrogen adsorption (specific surface area and porosity), low-temperature calorimetry (LTC) and thermal analysis. The main result is that the cement paste structure and porosity can be engineered by addition of selected layer silicates having specific particle shapes and surface properties (e.g., charge and specific surface area). This seems to be due to the growth of calcium-silicate-hydrates (C–S–H) on the clay particle surfaces, and the nano-structure of the C–S–H depends on type of layer silicate. The effect of layer silicate addition is most pronounced for palygorskite and smectite having the largest surface area and negative charges on the particle surfaces. The cement pastes containing palygorskite and bentonite have, in comparison to the pure cement paste and the paste containing kaolinite, a more open pore structure consisting of fine pores. Silica fume paste contains a significant amount of closed pores. As a secondary result, it is demonstrated that both the degree and duration of sample drying strongly modifies the structure of the cementitious materials under investigation.
77 citations
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TL;DR: The results indicate that the perception that arsenic, phosphate and other species compete for the same surface sites of iron oxides in sediments with properties similar to those of, for example a synthetic goethite, probably is not correct.
77 citations
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TL;DR: Jensen et al. as discussed by the authors used a sequence-based chrono-and biostratigraphy approach to estimate the transgression level of the Baltic Ice Lake in the southwestern Baltic.
Abstract: Jensen, J. B., Bennike, O., Witkowski, A., Lemke, W. & Kuijpers, A. 1997 (September): The Baltic Ice Lake in the southwestern Baltic: sequence-, chrono- and biostratigraphy. Boreas, Vol. 26, pp. 217–236. Oslo. ISSN 0300–9483.
This multidisciplinary study focuses on late-glacial deposits in the Mecklenburg Bay -Arkona Basin area. The sequence stratigraphical method has been used on shallow seismic and lithological data, in combination with biostratigraphical work and radiocarbon dating. Glacial-till deposits underlie sediments from two Baltic Ice Lake phases. Varved clay deposits from the initial phase cover the deepest parts of the basins. A prograding delta is observed at the western margin of the Arkona Basin, prograding from the Darss Sill area. The delta system is possibly related to a highstand dated at 12.8 ka. A maximum transgression level around 20 m below present sea level (b.s.l.) is inferred, followed by a drop in water level and formation of lowstand features. The final ice lake phase is characterized by a new transgression. The transgression maximum as observed in the Mecklenburg Bay is represented by transgressive and highstand deltaic deposits. These also indicate a maximum shore level of 20 m b.s.l. The deltaic sediments that contain macroscopic plant remains and diatoms have yielded Younger Dryas ages. Mapping of the late-glacial morphology of the Darss Sill area reveals a threshold at 23 to 24 m b.s.l. This means that the Baltic Ice Lake highstand phases inundated the Darss Sill, which implies that the westernmost extension of the Baltic Ice Lake reached as far as Kiel Bay. Forced regressive coastal deposits at the western margin of the Arkona Basin mark a lowstand level of around 40 m b.s.l. caused by the final drainage of the Baltic Ice Lake. The lowstand deposits predate lacustrine deposits from the Ancylus Lake, which date to approximately 9.6 ka BP.
77 citations
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TL;DR: A forced gradient tracer experiment indicated a rapid transport of a solute tracer, chloride, through a 13m thick fractured till-silty sand lens system to an underlying sandy aquifer in Ringe, Denmark as discussed by the authors.
77 citations
Authors
Showing all 903 results
Name | H-index | Papers | Citations |
---|---|---|---|
Charles P. Gerba | 102 | 692 | 35871 |
Jørgen E. Olesen | 79 | 495 | 25160 |
Søren J. Sørensen | 71 | 383 | 21259 |
Jason E. Box | 62 | 191 | 12146 |
Bo Elberling | 56 | 245 | 11059 |
Jan Heinemeier | 52 | 181 | 8696 |
Poul Løgstrup Bjerg | 52 | 244 | 9590 |
Paul F. Green | 50 | 200 | 13049 |
Philipp Mayer | 50 | 190 | 7867 |
Jens Christian Refsgaard | 48 | 194 | 10917 |
Ole Bennike | 45 | 216 | 6703 |
N. John Anderson | 45 | 102 | 5633 |
Richard H. W. Bradshaw | 44 | 122 | 8066 |
Carsten S. Jacobsen | 44 | 142 | 5525 |
Antoon Kuijpers | 44 | 132 | 5146 |