Cosmic ray exposure ages of iron meteorites, complex irradiation and the constancy of cosmic ray flux in the past

Technical Report · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6534587

Marti, K; Lavielle, B; Regnier, S

While previous calculations of potassium ages assumed a constant cosmic ray flux and a single stage (no change in size) exposure of iron meteorites, present calculations relaxed these constancy assumptions and the results reveal multistage irradiations for some 25% of the meteorites studied, implying multiple breakup in space. The distribution of exposure ages suggests several major collisions (based on chemical composition and structure), although the calibration of age scales is not yet complete. It is concluded that shielding-corrected (corrections which depend on size and position of sample) production rates are consistent for the age bracket of 300 to 900 years. These production rates differ in a systematic way from those calculated for present day fluxes of cosmic rays (such as obtained for the last few million years).

• Research Organization: Bordeaux-1 Univ., 33 (France)
• OSTI ID: 6534587
• Report Number(s): N-84-21455
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALI METALS
CHEMICAL COMPOSITION
COSMIC RADIATION
ELEMENTS
IONIZING RADIATIONS
IRON METEORITES
IRRADIATION
METALS
METEORITES
NUCLEAR REACTIONS
PALEONTOLOGY
POTASSIUM
RADIATIONS
TIME MEASUREMENT