Pressure estimations indicate that crystallization started at ~7 kbar and progressed up to surface levels.
Losantos, E. , Cebriá, J. M., Morán-Zenteno, D. J., Martiny, B. M., López-Ruiz, J. 2014, 'Condiciones de cristalización y diferenciación de las lavas del volcán El Metate (CampoVolcánico de Michoacán-Guanajuato, México)', Estudios Geologicoshttp://estudiosgeol.revistas.csic.es/index.php/estudiosgeol/article/view/914/988. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
These material pressures can reach hundreds of kbar and often exceed the material strengths by several orders of magnitude.
Key Christopher T., Schumacher Shane C., Alexander C. Scott 2015, 'Evaluation of a strain based failure criterion for the multi-constituent compositemodel under shock loading', EPJ Web of Conferenceshttp://dx.doi.org/10.1051/epjconf/20159404001. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Crystallization process of quartz diorites and trondhjemites occurred under isobaric conditions with 1.5-2.0 kbar and a slow cooling.
Sergei V. Pribavkin, Irina A. Gottman, Anatolii V. Korovko 2018, 'Petrology of Yaluninogorsk granitoid massive (Alapaevsk-Sukhoi Log porphyry copperzone, Middle Urals)', Литосфераhttps://test.lithosphere.ru/jour/article/view/136. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)