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Pupienis, D., Buynevich I.V., Jarmalavičius, D., Žilinskas, G., and Fedorovič, J., 2013. Regional distribution of Heavy-mineral concentrations along the Curonian Spit coast of Lithuania Heavy-mineral concentrations (HMCs) in coastal sands serve as important indicators of hydrometeorological and sedimentological conditions. Along the southeast Baltic Sea coast, quartz- and feldspar-rich sands contain variable amounts (1-8%) of heavy minerals, such as garnet, rutile, zircon, magnetite, ilmenite, hornblende, and other accessory minerals. Their concentrations are found along the Baltic Sea coast of the Curonian Spit, a 98-km-long barrier divided between the Russian Federation (47 km) in the south and the Republic of Lithuania (51 km) in the north. The open sea beach sites range from 25 to 80 m in width and are backed by 5-16 m height foredunes. To examine the patterns in HMC distribution, a total of 303 surface sand samples were collected from the middle of the beach, foredune toe, and stoss slope at 500 m intervals along the entire length of the Lithuanian section. To characterize the relative concentrations of heavy minerals (especially ferrimagnetic), a Bartington MS3 field scanning sensor was used for rapid and effective measurements of low-field volume magnetic susceptibility (MS). Along the Baltic Sea beach, in-situ MS values of κ< 50 μSI of background quartz-rich sands contrast with κ > 150 μSI in surface HMCs. On the beach, MS averages 38 μSI, whereas on the foredune toe and stoss slope they decrease to 33 and 26 μSI respectively. Furthermore, alongshore variations in beach HMC characteristics follow a cyclic pattern with a wavelength of approximately 10 km. This pattern is likely related to wave runup during major storms, whereas on the foredune toe and stoss slope, HMCs reflect the secondary reworking by aeolian processes. Along the sectors with higher MS, coastal erosion processes dominate (Pervalka-Nida), whereas low values generally correspond to regions of sand accumulation (Kopgalis-Pervalka). Therefore, surficial HMCs have the potential for characterizing long-term patterns of regional distribution of hydrodynamic energy along drift-aligned sandy coasts. [ABSTRACT FROM AUTHOR]

Long-term sea level rise is commonly considered to enhance coastal erosion, the rate of which is often evaluated using the Bruun Rule. We make an attempt to assess the recent coastal dynamics of the Curonian Spit in terms of the shoreline displacement rate on the basis of a comparison of maps from different years and coastal monitoring data. The obtained results are compared with those calculated according to the Bruun Rule. It was found that only individual-year average changes over the entire spit are linked to sea level variations, whereas long-term trends of shoreline dynamics are uncorrelated with the sea level increase. Although the sea level has increased in the study area, coastal recession has been observed since 1910 in the southern part of the Lithuanian sector of the Curonian Spit and accretion in the northern part, while the central part has been stable. [ABSTRACT FROM AUTHOR]

The 98-km-long Curonian Spit is fronted by beaches mainly composed of quartz sand with minor high-density fractions. In this study heavy-mineral concentration (HMC) trends and grain-size statistical parameters were used to assess their role as indicators of natural processes, human activities, and patterns of longshore transport. A total of 92 surface sand samples were collected at 1 km intervals from the middle of the beach along the Baltic Sea shoreline of the spit between Klaipėda strait in Lithuania and Zelenogradsk in Russia. HMC contribution was assessed in the laboratory using bulk low-field magnetic susceptibility (MS) as a proxy for ferrimagnetic and paramagnetic mineral content. Quartz-dominated (background) sand is generally characterized by low MS values of κ < 50 μSI, whereas higher values κ > 150 μSI are typical for heavy-mineral-rich sand. The greatest MS values along the middle of the beach occur in the southern part of the spit and are 40 times higher than in the northern sector. This pattern suggests the existence of a longshore particle flux with HMC distribution having the potential as a useful tracer of longshore sediment transport. Local anomalously high MS excursions are associated with contribution of iron-rich materials from adjacent man-made structures. Therefore, temporally constrained HMC distribution along the middle of the beach reflects the cumulative effect of antecedent geologic framework, longshore sediment transfer, erosional and accretionary processes, wave and wind climate, and local coastal protective structures. [ABSTRACT FROM AUTHOR]