Characterization of microstructures and perlitic textures may be carried out by combining volcanological and glass technical concepts, with supporting evidence from image analysis. These methods enable investigation of the mechanisms of protracted fracture formation, propagation, and characterization of fracture networks in silica-rich volcanic glass. Here we present analyses of rhyolitic lava and ignimbrites from different locations and geological ages. Our results allow characterization of the relationship between primary sublinear quench fractures and secondary rounded perlitic fractures, which together form a three-dimensional fracture network. Completely hydrated samples from the pre-Cenozoic show no variations in volatile fluid content within fractured glass but do show differential depletion in alkali contents, suggesting significant fluid-mediated alteration. In contrast, younger samples are incompletely hydrated and may demonstrate a connection between alkali mobility and rock hydration. Formation of primary fractures and a first generation of secondary fractures is caused by thermal shock close to the glass transition temperature. Formation and propagation of subsequent fracture generations is related to intrinsic stresses induced by the continued hydration of volcanic glass. We find that the pore space in rhyolitic rocks is not only influenced by fracture porosity or initial vitric porosity but may increase or decrease during post-emplacement, low-temperature alteration processes.

微观结构和珍珠岩纹理的表征可以通过结合火山学和玻璃技术概念以及图像分析的支持证据来进行。这些方法能够研究富硅火山玻璃中持久裂缝形成、扩展的机制以及裂缝网络的表征。在这里，我们对来自不同地点和地质年代的流纹质熔岩和熔结岩进行了分析。我们的结果可以表征初级亚线性淬火断裂和次级圆形珠光体断裂之间的关系，它们一起形成三维断裂网络。来自前新生代的完全水合样品显示碎裂玻璃内的挥发性流体含量没有变化，但确实显示出碱含量的不同消耗，提示显着的液体介导的改变。相比之下，较年轻的样品不完全水合，可能表明碱迁移率和岩石水合之间存在联系。一次断裂和第一代二次断裂的形成是由接近玻璃化转变温度的热冲击引起的。随后裂缝的形成和扩展与火山玻璃持续水合作用引起的内在应力有关。我们发现流纹岩中的孔隙空间不仅受到裂缝孔隙度或初始玻璃孔隙度的影响，而且在侵位后的低温蚀变过程中可能会增加或减少。一次断裂和第一代二次断裂的形成是由接近玻璃化转变温度的热冲击引起的。随后裂缝的形成和扩展与火山玻璃持续水合作用引起的内在应力有关。我们发现流纹岩中的孔隙空间不仅受到裂缝孔隙度或初始玻璃孔隙度的影响，而且在侵位后的低温蚀变过程中可能会增加或减少。一次断裂和第一代二次断裂的形成是由接近玻璃化转变温度的热冲击引起的。随后裂缝的形成和扩展与火山玻璃持续水合作用引起的内在应力有关。我们发现流纹岩中的孔隙空间不仅受到裂缝孔隙度或初始玻璃孔隙度的影响，而且在侵位后的低温蚀变过程中可能会增加或减少。