Cosmogenic isotopes production rates

Bhandari N, Bonino G, Cirri Castagnoli G (1994) The 11-year solar cycle variation of cosmogenic isotope production rates in chondrites. Meteoritics 29 443-444... 

Note After Bierman (1994), Gosse and Phillips (2001), and Lai (1988). See Gosse and Phillips (2001) for details about radionuclide decay constants and production rate uncertainties. Isotopes in italics are those that have been used routinely in cosmogenic nuclide studies. Stable isotopes will resolve paleoaltimetry for Cenozoic and older rocks. High-latitude, sea-level rates from empirical studies only. Production mostly via neutron spallation unless noted. Recent debate on die half-life of 10Be has focused on whether this number is off by >10%. 

Kouwenberg LLR, Kiirschner WM, McElwain JC (2007) Stomatal frequency change over altitudinal gradients prospects for paleoaltimetry. Rev Mineral Geochem 66 215-242 Lai D (1988) In situ-produced cosmogenic isotopes in terrestrial rocks. Ann Rev Earth Planet Sci 16 355-388 Lai D (1991) Cosmic ray labeling of erosion surfaces in situ nuclide production rates and erosion models. Earth Planet Sci Lett 104 424-439... 

Voshage H. and Hintenberger H. (1963) The cosmic-ray exposure ages of iron meteorites as derived from the isotopic composition of potassium and the production rates of cosmogenic nuclides in the past. In Radioactive Dating, International Atomic Energy Agency, Vienna, pp. 367-379. 

Masarik J, Nishiizumi K, Reedy RC (2001) Production rates of cosmogenic He, Ne, and Ne in ordinary chondrites and the lunar surface. Meteoritics Planet Sci 36 643-650 McCoy TJ, Keil K, Clayton RN, Mayeda TK, Bogard DD, Garrison DH, Wieler R (1997) A petrologic and isotopic study of lodranites evidence for early formation as partial melt residues from heterogeneous precursors. Geochim Cosmochim Acta 61 623-637... 

Terrestrial Cosmogenic isotopes and their Production Rates... 

The production rates of several cosmogenic isotopes in the earth s atmosphere are given in Table 2, along with their estimated global inventories. Some of the cosmogenic isotopes are also produced directly, in situ, in the upper layers of the oceans. The source strengths of cosmic ray-produced nuclei in the oceans, due to their production in the atmosphere, and direct production in the ocean water, are given in... 

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. 

All three isotopes of Ne are produced at almost equal rates by cosmogenic particles at the Earth s surface. As Ne is the least abundant isotope, cosmogenic production of Ne is more likely to be a significant portion of the crustal Ne budget than for Nc or Ne. Similarly, Ar is the least abundant isotope of Ar as well as the most rapidly produced (for typical crustal compositions), therefore the effects of cosmogenic Ar accumulation on the crustal noble gas budget will be examined. 

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