Epsilon values for individual rocks at the present day

The magnitude of the present-day Ej gj values reflects the degree of time integrated depletion in Nd relative to CHUR as expressed by the factor (see below). 

Epsilon values Epsilon values may be calculated from Sr/ Sr ratios in exactly the same way 

0 and 3.0 Ga are the lines which join the 0, 1.0, 2.0 and 3.0 Ga points on each growth curve. The 0 Ga isochron is known as the geochron. (c) A single-stage lead isochron for 

Calculating the Points on an Sm-Nd isochron typically plot far away from the origin. In order to uncertainties in obtain a greater degree of accuracy in determining the initial ratio, some 

This value may then be compared with CHUR to calculate the epsilon value using the equation 

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