UserCalc: A Web-based uranium series calculator for magma migration problems

Abstract

Measured departures from secular equilibrium in the uranium series decay chains provide important constraints on the rates of recent mantle and crustal processes. Nevertheless, the inferences drawn from these observations depend upon the models used to interpret them. While several useful models for U series exist, they are not all equally easy to use, and it is often the ease of use, rather than the utility of the model, that determines which models are applied. The purpose of this paper is to level the playing field by making some of the more general U series transport models accessible to a wider community through the UserCalc Web site available from Lamont-Doherty Earth Observatory at www.ldeo.columbia.edu/∼mspieg/UserCalc/. These models calculate the effects of both melting and melt transport on two U series chains (238U→230Th→226Ra and 235U→231Pa) and allow the user to input their own petrological insight and data to explore the behavior of this model. The purpose of the site is to provide a tool that can spur additional collaborations between geophysicists and geochemists as well as drive more rapid exploration/evolution of U series models.