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It is difficult to obtain fossil data from the 10% of Earth's terrestrial surface that is covered by thick glaciers and ice sheets, and hence, knowledge of the paleoenvironments of these regions has remained limited. We show that DNA and amino acids from buried organisms can be recovered from the basal sections of deep ice cores, enabling reconstructions of(More)
[1] Ice cores drilled from glaciers around the world generally contain horizons with elevated levels of beta radioactivity including 36 Cl and 3 H associated with atmospheric thermonuclear bomb testing in the 1950s and 1960s. Ice cores collected in 2006 from Naimona'nyi Glacier in the Himalaya (Tibet) lack these distinctive marker horizons suggesting no net(More)
Soil profiles from Bavaria in southern Germany and from Chile were analysed for (129)I by accelerator mass spectrometry (AMS), for (127)I by inductively coupled plasma mass spectrometry (ICP-MS), and for (137)Cs by gamma-spectrometry. The mean deposition density of (137)Cs in soils from Bavaria was (41×1.5(±1)) kBq m(-2) (geometric mean and geometric(More)
A first international (36)Cl interlaboratory comparison has been initiated. Evaluation of the final results of the eight participating accelerator mass spectrometry (AMS) laboratories on three synthetic AgCl samples with (36)Cl/Cl ratios at the 10(-11), 10(-12), and 10(-13) level shows no difference in the sense of simple statistical significance. However,(More)
Two long-lived halogen radionuclides (36 Cl, T 1/2 = 301 kyr, and 129 I, T 1/2 = 15.7 Myr) have been studied by means of Accelerator Mass Spectrometry (AMS) at the Uppsala Tandem Laboratory. The 36 Cl measurements in natural samples using a medium-sized tandem accelerator (∼1 MeV/amu) have been considered. A gas-filled magnetic spectrometer (GFM) was(More)
Activation measurements of materials exposed to nuclear bomb explosions are widely used to reconstruct the neutron flux for retrospective dosimetry. In this study the applicability of coral CaCO3 as a biogenic neutron fluence dosimeter is tested. The long-lived radioisotopes (41)Ca, (14)C and (10)Be, which had been produced in nuclear bomb explosions, are(More)