Chlorine-36 is produced in rocks at the earth's surface almost entirely by cosmic-ray-induced reactions. PHILLIPS, 1994, 36-Cl surface exposure determinations of eruption ages for quaternary lava flows of the Zuni-Bandera volcanic field: New Mexico Geology, v. These include spallation of 39-K and 40-Ca, and thermal neutron activation of 35-Cl.

Cosmogenic nuclides are rare nuclides that form in surface rocks because of bombardment by high-energy cosmic rays[3].

The chlorine-36 method (Phillips et al., 1986) is based on the fact that 36-Cl is dominantly produced by cosmogenic reactions near the earth's surface, primarily in the upper 1 m.

of an exposed rock, as compared to a very small amount of production in the deeper subsurface.

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Hot tip: Video ads won’t appear to registered users who are logged in. Title: Cosmogenic Dating 1Cosmogenic Dating 2Introduction l A group of isotopic methods of age determination based on accumulation of certain nuclides, which are produced only in the top few meters of the crust.