ApTimer: a calculator of the timescale of F-Cl-OH diffusion in apatite

Instruction:

This calculator is developed for estimating the timescale of multicomponent (F-Cl-OH) diffusion in apatite, and it can be applied to natural apatite that is zoned of F/Cl/OH. The calculated diffusion times can be related to magmatic processes such as magma ascent.

Detailed experimental and computation methods as well as the model applications can be found in the paper below:
Li, W., Chakraborty, S., Nagashima, K, & Costa, F (2020a). Multicomponent diffusion of F, Cl, OH in apatite with application to magma ascent rates. Earth and Planetary Science Letters. 550, 116545. (DOI:10.1016/j.epsl.2020.116545)

Input:

Measured diffusion profile: Please use the provided data template (.csv) to organise your data, and upload the csv file using the green button below.

Parameters for diffusion modelling:

Temperature (oC):
Angle between traverse and the c-axis of apatite:
DCl:     m2/s
DF:     m2/s
DOH:     m2/s

Initial & boundary conditions:

Initial conditions Left boundary Right boundary
XCl
XF
XOH

Distance & time steps: dx and dt have to be ≤ 1

Distance step, dx: µm
Time step, dt: hours
Iteration:
You can change the input and run the model again!

Model fits:

Best-fit time and uncertainty: