naa a22 4500 510765122 CHVBK 20180411083154.0 cr unu---uuuuu 180411e20130501xx s 000 0 eng 10.1134/S0001437013030041 doi (NATIONALLICENCE)springer-10.1134/S0001437013030041 Age and growth rates of ferromanganese concretions from the gulf of Finland derived from 210Pb measurements [Elektronische Daten] [A. Grigoriev, V. Zhamoida, K. Gruzdov, R. Krymsky] The formation of ferromanganese concretions on continental shelves is a widespread recent biogeochemical process, which is particularly intense in the Baltic Sea. The proposed new technique for dating ferromanganese concretions is based on the equilibrium 210Pb, which is produced immediately within them due to the decay of 226Ra, which is intensely sorbed by concretions from the seawater. This method is principally different from the traditional dating of bottom sediments using nonequilibrium 210Pb, which represents a decay product of atmospheric Ra. A mathematical tool for the calculation of the concretion ages is proposed. The latter is used for calculating the ages and growth rates of ferromanganese concretions belonging to two morphological varieties. The age and average growth rates of spheroidal concretions are estimated to be 670-850 years and 0.014 mm/year, respectively. The central part of a pancake-shaped concretion is dated back to 2500-3800 years, and its calculated respective horizontal and vertical growth rates are approximately 0.028 and 0.004 mm/year. Pleiades Publishing, Ltd., 2013 Grigoriev A. Karpinsky All-Russian Research Institute of Geology (VSEGEI), pr. Srednii 74, 199106, St. Petersburg, Russia aut Zhamoida V. Karpinsky All-Russian Research Institute of Geology (VSEGEI), pr. Srednii 74, 199106, St. Petersburg, Russia aut Gruzdov K. Karpinsky All-Russian Research Institute of Geology (VSEGEI), pr. Srednii 74, 199106, St. Petersburg, Russia aut Krymsky R. Karpinsky All-Russian Research Institute of Geology (VSEGEI), pr. Srednii 74, 199106, St. Petersburg, Russia aut Oceanology SP MAIK Nauka/Interperiodica 53/3(2013-05-01), 345-351 0001-4370 53:3<345 2013 53 11491 https://doi.org/10.1134/S0001437013030041 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1134/S0001437013030041 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Grigoriev A. Karpinsky All-Russian Research Institute of Geology (VSEGEI), pr. Srednii 74, 199106, St. Petersburg, Russia aut NATIONALLICENCE 700 1- Zhamoida V. Karpinsky All-Russian Research Institute of Geology (VSEGEI), pr. Srednii 74, 199106, St. Petersburg, Russia aut NATIONALLICENCE 700 1- Gruzdov K. Karpinsky All-Russian Research Institute of Geology (VSEGEI), pr. Srednii 74, 199106, St. Petersburg, Russia aut NATIONALLICENCE 700 1- Krymsky R. Karpinsky All-Russian Research Institute of Geology (VSEGEI), pr. Srednii 74, 199106, St. Petersburg, Russia aut NATIONALLICENCE 773 0- Oceanology SP MAIK Nauka/Interperiodica 53/3(2013-05-01), 345-351 0001-4370 53:3<345 2013 53 11491 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer