Geosciences programming

The epsilon Nd (${ϵ}_{Nd}$) is a widely used parameter to understand the processes of rock forming, i.e. petrogenetic processes from both geochemical and geochronological approach. By definition, ${ϵ}_{Nd}$ is the difference of ${}^{143}Nd{/}^{144}Nd$ of rock sample and ‘chondritic uniform reservoir’ at the time in the past T. For a rock of age T, ${ϵ}_{Nd}\left(T\right)$ is the ‘initial’ value of ${ϵ}_{Nd}$; the value at the time of crystallization of the rock, and ${ϵ}_{Nd}\left(0\right)$ is the measured value (dePaolo, 1981). We use the same form as in (dePaolo, 1981) as we will the author’s propose of ${ϵ}_{Nd}$ curve, therefore, the value of ${ϵ}_{Nd}$ is :

$${ϵ}_{Nd}\left(T\right)={10}^4\left[\frac{{(}^{143}Nd{/}^{144}Nd{)}_{rock}\left(T\right)}{{(}^{143}Nd{/}^{144}Nd{)}_{CHUR}\left(T\right)}-1\right]$$