Eemian and Weichselian stratigraphy in South Sweden

The stratigraphy of Pleistocene sequences within three main areas of the province of Skane, South Sweden, is discussed. The traditional stratigraphy is revised. New lithostratigraphic units are deficned and named according to international stratigraphic terminology. Lithostratigraphical correaltions are based on sedimentological development and palaeoenvironmental changes. Organic beds are correlated with the Eemain interglacial and some of the Early and Middle Weichselian interstadials. The chronostratigraphic key site, Stenberget, is described in greater detail. Stratrigraphy and palaeoenvironment are summarized in a scheme indicating that South Sweden was glaciated only during the period 21,000–13,000 B.P.     

The subdivision of the Quaternary of Norden: a discussion

The proposal for Quaternary stratigraphy of Norden published 1974 by Mangerud, Andersen, Berglund & Donner was discussed at a Nordie meeting 1978. On the basis of this discussion some recommendations are proposed here which deviate slightly from the 1974 proposal: (1) the term Flandrian should not be used in Norden until it is properly defined in the type area, (2) the Middle/Late Weichselian boundary should provisionally be defined as 25,000 ¹⁴C years B. P. In addition it was stated that there is an urgent need for complete subdivision of the Weichselian into a continuous chronozone sequence.     

Late Weichselian and Holocene environments of lake Endletvatn, Andφya, northern Norway: as evidenced primarily by chemostratigraphical data

A 6.5 m long sediment succession (18.5-2.2 ka BP) from the northern sub-basin of lake Endletvatn was analysed lithologically, palynologically and chemically. The chemical analyses were performed at about 10 cm depth intervals for the following parameters: total organic C, N, P, Fe, Mn, Mg, Na, K, Ca and S, in addition to water content, dry density, and pH. Two main lithostratigraphical units can be distinguished, which also differ substantially in chemical characters. Five chemostratigraphical main units were distinguished. The two lowermost units 1-2 (18.5-12.9 ka BP) correspond to the lower lithostratigraphical main unit and are characterized by minerogenous sediments with low C and N, and high Fe, Mg and K. P is low, partly because of a scarcity of P in parent rocks. Chemostratigraphical unit 3 (12.9-9.6 ka BP) is characterized by increasing C and N and a high N/P ratio (10-20) culminating in the early part of the Younger Dryas, indicating abundant N available for bio-production. The Fe, Mg, and K content is still high, but decreasing, indicating decreasing glacial and kryogenic erosion and allogenic deposition until c. 10.5 ka BP. A hiatus represented by a sand layer covers most of the time-span 10.5-9.6 ka BP. Chemostratigraphical unit 4 (9.6-5.3 ka BP) represents the Holocene thermal optimum in three subunits. In the time interval 9.6-9.1 ka BP, Fe, Mg and K decrease to a minimum and P shows a pronounced increase. The megathermal period c. 8200-5300 BP, is characterized by maxima of C, N and P and a minimum of Fe. The katathermal period after 5.3 ka BP is characterized primarily by increased Fe precipitation, increasing Fe/Mn ratio, and P, C and N at a constantly lower level than during the megathermal. A stable C/N ratio of about 10, of the sediment interval younger than 12.9 ka BP characterizes the sediments as transitional between gyttja and dy. The Holocene lake type varied between weakly oligohumic and mesohumic. Stagnant bottom waters (reducing conditions) occur in the periods 12.9-11.5 ka BP and c. 7.5-5.3 ka BP. The climatic development and other environmental implications of the joint chrono-, chemo-, litho- and biostratigraphical data set are discussed.     

Evaluation of Air Pollution Trend Using GIS and RS Applications in South West of Iran

In this paper, remote sensing and GIS have been used to assess the status of NO₂ at the south west of Iran. 221 data about concentration of NO₂ was extracted from Ozone Monitoring Instrument. Ordinary kriging and inverse distance weighting interpolation methods was used to interpolate data. Results showed that ordinary kriging method using cross-validation have had less error. North east of the study area has the highest concentration of NO₂ (329 molecule/cm²) and the concentration of NO₂ decreases from north east to South west of the study area. On the other hand, data trend results showed that the data seems to exhibit a fairly strong trend in the east west direction and a weaker one in the north–south direction.     

Late Quaternary history of northern Russia and adjacent shelves — a synopsis

This synopsis highlights some of the main results presented in this issue of Boreas. The collection of papers deals with ice sheet reconstruction in space and time, isostatic and eustatic response to deglaciation, land to shelf sediment interaction, and Eemian and Holocene environmental variations. The most significant new results are that the last glacial maximum of the Kara Sea and Barents Sea ice sheets were both much smaller and much older than in most previous hypotheses. This puts new constraints on, for example, climate and ice sheet linkages, ice sheet interactions (Scandinavian-Barents Sea-Kara Sea), and land-ocean riverine input through time.     

Estimation of the maximum credible hazard in Kuala Lumpur and Singapore due to gigantic Sumatran megathrust earthquakes: based on a comparative study on attenuation laws

Natural Hazards - This paper has classified nine attenuation laws derived for subduction interface earthquakes through a comparative study based on the peak ground accelerations (PGAs) recorded in...     

Palynodebris analysis of a shallow core from the Barents Sea

A quantitative study of palynomorphs and palynodebris in a shallow core from the central part of Bjørnøyrenna, western Barents Sea, is presented. The core could be subdivided into a lower part characterized by a complete dominance of reworked plant debris of Mesozoic age and an upper part with considerable input of first cycle algal debris and dinoflagellate cysts. Two hypotheses are suggested to explain this radical change in palynodebris composition. Either it represents a transition from a situation with permanent ice to normal marine conditions, or the absence of first cycle plant debris in the lower part of the core is caused by a masking of this component due to extremely high input of glacially eroded material from the bordering shallow parts of the Barents Sea. The present study shows that palynodebris analysis may contribute important information to the study of composition and depositional environment of Quaternary marine sediments in the area.     

The Late Quaternary Skagerrak and its depositional environment

The Skagerrak is a key region for our understanding of the Late Quaternary history of the East North Sea, of the entire Baltic basin and of the adjacent Scandinavian land areas. The depositional history of the postglacial Skagerrak began after the ice margin withdrew from Jutland to close to the modern Norwegian coast around 14 ka B.P. to 13 ka B.P. The Skagerrak was immediately filled by marine waters from the Norwegian Sea, but retained a fjord-like shape until approximately 10.2 ka B.P., when a connection opened across central Sweden to the Baltic Ice Lake. This seaway closed around 9 ka B.P., but a new seaway to the Baltic basin opened subsequently (probably close to 8.5 ka B.P.) through the Danish Belts. At about 10 ka B.P. the Skagerrak 'fjord' also started to change shape due to the flooding of the large former land area under the modern North Sea. Paleo-geography and -bathymetry of these changes can now be quantified in great detail. The young Quaternary sediments of the Skagerrak consist of fine-grained clays with minor amounts of silty and sandy material and are mostly of terrigenous origin, whereas biogenic components in general make up only a minor proportion of the bulk sediment. Prior to 10 ka B.P. a major portion of these deposits originated from the Fennoscandian regions N and E of the Skagerrak, while ice-rafting contributed coarse terrigenous components to the usually fine-grained sediments and while it was filled by brackish surface and cold polar bottom waters. At approximately 10 ka B.P., more temperate waters started to fill the Skagerrak and a good portion of the sediment seems to have originated from areas to the South. The Norwegian Coastal Current can only be documented for the past 7 ka; subtle changes of the pelagic and benthic environments could also be documented for later intervals.