Cosmogenous

In the marine environment, the numerous radionuclides can be classified into three broad categories based on their production or origin (1) those derived from the weathering of continental rocks, the primordial radionuclides, (2) those formed from cosmic radiation, the cosmogenic radionuclides, and (3) those artificially introduced into nature, the anthropogenic or transient radionuclides and tracers. The primordial radionuclides (e.g. Th, and U) were... 

Cosmogenic radionuclides are formed in the upper atmosphere by the interaction of cosmic rays, primarily from the sun, with elements present in the atmosphere (e.g. 0, and " Ar). Their half-lives range from months to... 

Cosmogenic radionuclides are produced in the upper atmosphere by spallation reactions of cosmic rays with atmospheric elements. The most common... 

An alternative method for inferring accumulation rate relies on assuming that the rain of cosmogenic nuclides such as °Be onto the ice sheet surface is known. Then high accumulation rate dilutes the cosmogenic nuclide so its concentration as measured in the ice core is inversely proportional to accumulation rate. 

The geochemistry of marine sediments is a major source of information about the past environment. Of the many measurements that provide such information, those of the U-series nuclides are unusual in that they inform us about the rate and timescales of processes. Oceanic processes such as sedimentation, productivity, and circulation, typically occur on timescales too short to be assessed using parent-daughter isotope systems such as Rb-Sr or Sm-Nd. So the only radioactive clocks that we can turn to are those provided by cosmogenic nuclides (principally or the U-series nuclides. This makes the U-series nuclides powerful allies in the quest to understand the past ocean-climate system and has led to their widespread application over the last decade. 

Fludd, Robert. The cosmogenic experiments of Robert Fludd a translation with introduction and commentary by D. Graham Burnett... 

Pb-210 and the Cosmogenic Radionuclides. We noted earlier that our measurements of Pb-214 were really measurements of Po-214 decay, that is, the production of Pb-210. The mean AMAD of these measurements was about 0.16 um, with the AMAD of Pb-210 predicted to be 0.18 um after recoil. However, the summer AMAD of Pb-210, after aging in the atmosphere for about a week (Moore et al., 1980), was closer to 0.4 um, indicating that Pb-210 s AMAD approximately doubles during its lifetime in the atmosphere. The limited measurements reported here suggest that the AMAD of Pb-210 is smaller in winter than summer, possibly reflecting differences in aerosol growth rates. The summer measurements were also not different from simultaneous SoJ measurements. 

The cosmogenic radionuclides, particularly Be-7, are associated with slightly smaller aerosols than sulfate, both in winter and summer. The reasons for this difference may be either (1) faster growth rates of secondary aerosols in plumes... 

H.E. Suess, Secular variations of cosmogenic 14 C on earth their discovery and interpretation, Radiocarbon 28, 259 265 (1986). 

In the DBD region, two peaks appear, one below the (3(3-Ov Q value and one above. They are due respectively to the 60Co sum line (2505.5 keV) and the 208T1 line (2615 keV). The first is ascribed to a 60Co contamination of the copper structures due to cosmogenic... 

Cosmogenic Radionuclides in the 105-107 Year Region Results and Prospects for High-Energy Ion Counting...J. R. Arnold. 

Cosmogenic Nuclides Isotopes of elements produced by the action of... 

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