Description Usage Arguments Note Author(s) References Examples
"dluskora1" is a useful function to simulate diffusion-limited REE uptake by a growing eclogite garnet. This is another version of the program given by Skora et al. (2006). With this function, we can calculate theoretical REE profiles of a given garnet by setting various parameters which control the growth process of the garnet.
1 | dluskora1(fac1, Q, syR, c_ave, D_0, R, T_1, T_2, K_d, Mr, Mt, fg, ft, garsize)
|
fac1 |
This parameter equals D_0/A [cm]. A is the garnet growth coefficient (r = A t^(fg)). The meanings of D_0 and fg are shown below. This corresponds to the parameter "u" in Fukushima et al. (2021). |
Q |
The activation energy of REE diffusion around the garnet [J/mol] |
syR |
The radius of the system of which the garnet is located at the center [cm] |
c_ave |
The initial concentration of REE in the system [ppm] |
D_0 |
The pre-exponential factor of the REE diffusion coefficient around the garnet [cm^2/year] |
R |
The universal gas constant [m^2 kg s^(-2) K^(-1) mol^(-1)] |
T_1, T_2 |
This function can simulate a situation where the temperature around the system increased and you can set the initial and final temperatures. T_1 is the initial temperature [degree Celsius] and T_2 is the final temperature [degree Celsius]. |
K_d |
The partition coefficient > 1 (REE concentration of garnet over REE concentration of the matrix) |
Mr, Mt |
The numbers of spatial (radial) and time meshes, respectively |
fg |
The exponent of the garnet's growth law. If you set fg as 1, the garnet will grow with the linear growth rate law: r = A t. |
ft |
The exponent of the temperature-increase law. If you set ft as 1, the temperature will increase with the linier increase rate law: T = B t. |
garsize |
The final radius of the garnet [cm] |
>K_d and A do not depend on temperature in this function. Temperature increase affects only the REE diffusion coefficient around the garnet.
>Diffusion in the garnet is ignored.
>This program is based on a Crank-Nicholson scheme (Crank 1975).
>This function returns "mass_gain_percent" with the REE profile plot. Please check whether its absolute value is very small(~e-4). Your result is not appropriate when the value is too big.
Ryo Fukushima
Crank J (1975) The mathematics of diffusion. Oxford University Press, p414
Fukushima R, Tsujimori T, Aoki S, Aoki K (2021) Trace-element zoning patterns in porphyroblastic garnets in low-T eclogites: Parameter optimization of the diffusion-limited REE-uptake model. Isl Arc 30:e12394
Skora S, Baumgartner LP, Mahlen NJ, Johnson CM, Pilet S, Hellebrand E (2006) Diffusion-limited REE uptake by eclogite garnets and its consequences for Lu–Hf and Sm–Nd geochronology. Contrib Mineral Petrol 152:703-720
1 2 3 |
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.