A note on the computation of Meissl’s smoothing coefficients βℓ

This note gives a new, short and non-recursive formula for Meissl’s smoothing coefficients β_?.     

Seed-like hydroptilid larval cases (Insecta: Trichoptera) from Holocene freshwater deposits

The seed-like larval cases of hydroptilid caddis flies may be mistaken for plant remains in subfossil studies. However, being correctly identified, they may be important for the interpretation of former freshwater environments. Two such subfossil caddis fly remains from Holocene lake sediments and river deposits are described morphologically and their palaeoecological significance interpreted.     

Spatial patterns of frequent floods in Switzerland

This study investigates the spatial dependence of high and extreme streamflows in Switzerland across different scales. First, using 56 runoff time series from Swiss rivers, we determined the average length of high-streamflow events for different levels of extremeness. Second, a dependence measure that expressed the probability that streamflow peaks would meet or exceed streamflow peaks at a conditioning site was used to describe and map the spatial extent of joint streamflow-peak occurrences across Switzerland. Third, we analysed the spatial patterns of jointly occurring high streamflows using cluster analysis to identify groups that react similarly in terms of flood frequency at different sites. The results indicate that, on a coarse scale, high and extreme streamflows are asymptotically independent in the main Swiss basins. Additionally, mesoscale tributaries in the main basins show distinct flood regions across river systems.     

Holocene sedimentary and environmental development of Aarhus Bay,Denmark – a multi-proxy study

Holocene sedimentation patterns and environmental development in Aarhus Bay, Denmark, were reconstructed based on proxy analyses of two sediment cores (M1 and M5). Together, the two cores offer an opportunity to examine the history of the area during the past c. 10 000 years. The investigation consisted of acoustic mapping and multi-proxy analyses of the sediment cores including macrofossils, sediment physical properties, sediment accumulation rates, grain size, and X-ray fluorescence elemental counts. Radiocarbon dating of the two sediment successions revealed that they cover the periods c. 10 000–3700 cal. a BP (M1) and c. 4400 cal. a BP to the present (M5). The data from the M1 site indicate the presence of a near-shore lake environment between c. 10 000 and 9000 cal. a BP. The first intrusion of marine water into the area is dated to c. 9000 cal. a BP. In the following c. 1300 years, brackish-water conditions prevailed in the area characterized by a mixture of taxa from marine, limnic and terrestrial habitats, reflecting a shallow estuarine environment. Around 7700 cal. a BP full marine conditions were established, accompanied by a marked increase in sedimentation rates. The changes to full marine conditions and higher sedimentation rates are probably due to a significant sea-level rise leading to flooding of former land areas and intensified erosion. A subsequent distinct decrease in sedimentation rates around 6350 cal. a BP is presumably linked to a previously documented sea-level drop about this time. Continuous sedimentation ceased around 3700 cal. a BP in the central part of the bay, most probably due to a major sea-level lowering involving widespread erosion. In the eastern and deeper part of the bay, sedimentation continued until today. Fully marine conditions prevailed there for at least the last 4400 years.     

Fluorine in Twenty-Two International Reference Rock Samples and a Compilation of Fluorine Values for the USGS Reference Samples

Fluorine in 22 international reference samples has been determined with an ion selective electrode following fusion with a Na₂bCO₃-ZnO mixture. To eliminate the effect of fluorine complexes in the solutions, the results presented are means of fluoride determinations from a standard calibration curve and from the method of standard addition. Together with these new determinations an updated compilation of USGS-I reference samples is presented.     

Geological indications for Palaeogene uplift in the eastern North Sea Basin

The timing and effect of the Cenozoic uplift of Scandinavia has been investigated using a multi-disciplinary approach involving sedimentological, seismic and biostratigraphic data from the Danish and the adjacent Norwegian parts of the North Sea Basin. It is concluded that significant uplift took place periodically throughout the Palaeogene possibly marking an earlier onset of the so-called “Neogene uplift” of Scandinavia. This conclusion is based on a number of sedimentological observations, including smectite content, grain-size variations, kaolinite thermal stabilities and T_max values supported by seismic reflection geometries and biostratigraphic data. These data indicate several phases of re-working of Palaeogene and older sediments situated further to the east and northeast during the middle to late Eocene and during the middle to late Oligocene. The tectonic patterns were similar during the late Paleocene and the Oligocene with some inversion taking place, whereas no inversion has been observed during the Eocene. Main provenance areas were to the north and northeast during the Paleocene and Oligocene, whereas the Eocene sediments originate mainly from the British Isles to the west. It is proposed that Palaeogene uplift of Scandinavia was associated with regional tectonic movements along crustal zones of weakness, which were reactivated as they accommodated strain induced by the Alpine Orogeny and the opening of the North Atlantic.