 
Summary: A Statistical Test of the Two Reservoir Model for Helium Isotopes
Don L. Anderson
California Institute of Technology
Pasadena, CA 91125 U.S.A.
TEL: 626.395.6901
FAX: 626.564.0715
Email: dla@gps.caltech.edu
18 June 2001
Earth and Planetary Science Letters
Page 2 18 June 2001
A Statistical Test of the Two Reservoir Model for Helium Isotopes
Abstract
A common hypothesis is that helium isotopes in mantlederived materials represent two
distinct populations, the midocean ridge (MORB) reservoir and the oceanic island (OIB)
reservoir. We ask the question "Can we disprove the null hypothesis that OIB and MORB
samples are drawn from the same population distribution function?" The answer is no, meaning
that the datasets could be drawn from the same population. Previous studies have reached the
opposite conclusion by comparing extreme values in one population with the mean value, or
range, of the other population after the extreme values are removed. The variance of the 3
He/4
