# Experimental Investigation of Lithium Partitioning among Plagioclase, Rhyolitic Melt, and H2O Vapor

Maylis Dupont de Dinechin, Caroline Martel, Hélène Balcone-Boissard, Monika Rusiecka, Rémi Champallier, Etienne Deloule

► To cite this version:

Maylis Dupont de Dinechin, Caroline Martel, Hélène Balcone-Boissard, Monika Rusiecka, Rémi Champallier, et al. Experimental Investigation of Lithium Partitioning among Plagioclase, Rhyolitic Melt, and H2O Vapor. EGU General Assembly 2024, Apr 2024, Vienne (AUT), France. 2024, 10.5194/egusphere-egu24-14481. [hal-04600373](https://hal.science/hal-04600373)

HAL Id: hal-04600373

https://hal.science/hal-04600373

Submitted on 6 Jun 2024

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# Experimental determination of lithium partition coefficients between plagioclase, rhyolitic melt, and H2O vapor

Maylis DUPONT DE DINECHIN,

Caroline MARTEL, Hélène BALCONE-BOISSARD and Monika RUSIECKA

Volcanic products contain minerals and elements that open windows onto underground volcanic processes.

Lithium is one of these trace elements. Lithium is a rare element on Earth, best known for its use in industry, healthcare, ceramics and battery applications.

But what about its usefulness in volcanology?

In volcanology, the objective is to better understand volcanic hazards in space and time. So we're looking for tracers and chronometers that can better constrain volcanic processes.

3 Li

6.94 g/mol

## Li abundance in volcanic rocks

<figure><img src="image_2.png" /><figcaption>Li is a rare element in the cosmos, but it is concentrated in certain rocks (pegmatites) and phases (brines). It is also hidden in magmatic rocks at low concentrations</figcaption></figure>

## Li partition between phases

Partition coefficients were obtained over a wide range of temperatures and pressures.

<figure><img src="image_3.png" /><figcaption>Partition coefficients were obtained over a wide range of temperatures and pressures.</figcaption></figure>

## Li mobility

Intracrystalline diffusion is caused by a chemical gradient between zones of a crystal of different composition, witnessing variable growth conditions.]This gradient balances with time via the diffusion of certain elements that serve as tracers to constrain the time of the magmatic process at the origin of this compositional gradient

Lithium is an element littlebut very mobile: a chronometer for rapid processes

Diffusion rates (D) vary according to the minerals or glasses.

<figure><img src="image_4.png" /></figure>

?

How does Li behave when magma rises ?

How is lithium distributed during magma ascent between the liquid, mineral and gaseous phases?

How can we study it?

## In situ crystallization experiments of plagioclase microlites

<figure><img src="image_5.png" /></figure>

## Experimental approach

<figure><img src="image_6.png" /><figcaption>Experiments about partition coefficients of Li between plagioclases, melt and fluid phase.</figcaption></figure>

Method:
Nucleation and growth
of microlites of plagioclases

<figure><img src="image_7.png" /><figcaption>Initial rhyolitic materials, water saturated and doped in Li (2000ppm, 1000ppm and 500ppm)</figcaption></figure>

<figure><img src="image_8.png" /></figure>

## Conclusion

In situ crystallization experiments of plagioclase microlites give more informations about the distribution of Li in magmatic systems. These experiments provide a better understanding of Li's behavior under different conditions. We can observe which parameters influence Li and what effect it has on the system.

**Li is small but powerfull.**

As the third element on the periodic table, lithium's characteristics make it an interesting elements to study, helping us to better understand pre, syn-eruptive processes (ascent rate, degassing).
<figure><img src="image_2.png" /></figure>

# Experimental determination of lithium partition coefficients between plagioclase, rhyolitic melt, and H2O vapor

Maylis DUPONT DE DINECHIN,

Caroline MARTEL, Hélène BALCONE-BOISSARD and Monika RUSIECKA

Volcanic products contain minerals and elements that open windows onto underground volcanic processes.

Lithium is one of these trace elements. Lithium is a rare element on Earth, best known for its use in industry, healthcare, ceramics and battery applications.

But what about its usefulness in volcanology?

In volcanology, the objective is to better understand volcanic hazards in space and time. So we're looking for tracers and chronometers that can better constrain volcanic processes.

3
Li

6.94 g/mol

## Li abundance in volcanic rocks

<figure><img src="image_3.png" /><figcaption>Li is a rare element in the cosmos, but it is concentrated in certain rocks (pegmatites) and phases (brines). It is also hidden in magmatic rocks at low concentrations</figcaption></figure>

## Li partition between phases

<figure><img src="image_4.png" /><figcaption>Partition coefficients were obtained over a wide range of temperatures and pressures.</figcaption></figure>

## Li mobility

Intracrystalline diffusion is caused by a chemical gradient between zones of a crystal of different composition, witnessing variable growth conditions.]This gradient balances with time via the diffusion of certain elements that serve as tracers to constrain the time of the magmatic process at the origin of this compositional gradient

Lithium is an element littlebut very mobile:
a chronometer for rapid processes

<figure><img src="image_5.png" /></figure>

?

How does Li behave when magma rises ?

How is lithium distributed during magma ascent between the liquid, mineral and gaseous phases?

How can we study it?

## Experimental approach

<figure><img src="image_6.png" /><figcaption>Experiments about partition coefficients of Li between plagioclases, melt and fluid phase.</figcaption></figure>

Method:
Nucleation and growth
of microlites of plagioclases

<figure><img src="image_7.png" /><figcaption>Initial rhyolitic materials, water saturated and doped in Li (2000ppm, 1000ppm and 500ppm)</figcaption></figure>

<figure><img src="image_8.png" /></figure>

## Conclusion

In situ crystallization experiments of plagioclase microlites give more informations about the distribution of Li in magmatic systems. These experiments provide a better understanding of Li's behavior under different conditions. We can observe which parameters influence Li and what effect it has on the system.

Li is small but powerfull.

As the third element on the periodic table, lithium's characteristics make it an interesting elements to study, helping us to better understand pre, syn-eruptive processes (ascent rate, degassing).

## Work in progress

From Dupont de Dinechin et al. (in progress)

<figure><img src="image_9.png" /></figure>

<figure><img src="image_10.png" /></figure>

?

Kd dependent of An ?

<figure><img src="image_11.png" /></figure>

<figure><img src="image_12.png" /></figure>

<figure><img src="image_13.png" /></figure>

<figure><img src="image_14.png" /></figure>

Effect on An content ?

<figure><img src="image_15.png" /></figure>

Effect on solubility ?

<figure><img src="image_16.png" /></figure>

## Futur work

Continue work on Li partition coefficients by making the system more complex: system with brine
Integrate ab initio calculation to study the integration of Li in a crystalline mesh.
Better constrain its use in volcanology by verifying what Li more precisely time

?

For more information, please contact
maylis.dupont_de_dienchin@sorbonne-universite.fr

<figure><img src="image_17.png" /></figure>
<figure><img src="image_9.png" /></figure>
<figure><img src="image_18.png" /></figure>