Silicic calderas globally tend to record a cyclic magmatic, structural, and eruptive evolutionary progression. Some calderas are polycyclic, involving multiple catastrophic collapses in the same approximate location. Here we discuss five examples from well-studied, geologically-young and active magmatic systems: The Kos-Nisyros Volcanic Complex (Greece), Long Valley (USA), Campi Flegrei (Southern Italy), Rabaul (Papua New Guinea), and Okataina (New Zealand) in order to gain insights on the inner workings of caldera systems during the build up to and recovery from large explosive eruptions. We show that the sub-caldera magmatic system evolves through a series of processes, here collectively termed “caldera cycle”, that are common to monocyclic and polycyclic calderas. In the case of polycyclic calderas, they accompany the transition from one caldera-forming eruption to the next. The caldera cycle comprises (1) the period of pre-collapse activity (incubation, maturation, widespread presence of a magmatic volatile phase), (2) the catastrophic caldera-forming (CCF) eruption, and (3) post-collapse recovery (resurgence, renewed eruptions, subsequent maturation) or the possible cessation of the cycle. The incubation phase corresponds to a period of thermal maturation of the crust, during which eruptions are frequent and of small volume due to the limited capability of reservoirs to grow. During the maturation phase, magma reservoirs gradually grow, coalesce, homogenize, magmas differentiate, and eruption frequency decreases. The system transitions into the fermentation phase once an exsolved magmatic volatile phase is continuously present in the reservoir, thereby increasing the compressibility of the magma and instigating a period of runaway growth of the reservoir. A CCF eruption at the end of the fermentation phase could be the concatenated result of multiple magmatic processes (including magma recharge, volatile exsolution, and crystal mush remelting) pressurizing the reservoir, while external factors (e.g., tectonic processes) can also play a role. Postcaldera eruptions, subvolcanic intrusions, and hydrothermal activity typically continue, even if the magma supply wanes. If, however, magma supply at depth remains substantial, the system may recover, initially erupting the remobilized remains of the CCF reservoir and/or new recharging magmas until a shallow reservoir starts to grow and mature again. Placing other calderas worldwide within this framework would enable to test the robustness of the proposed framework, deepen the understanding of what controls the duration of a cycle and its individual phases, and refine the petrologic, geophysical, and unrest symptoms that are characteristic of the state of a system.

全球范围内的硅质破火山口倾向于记录周期性的岩浆，结构和喷发性的演化过程。一些破火山口是多环的，在相同的近似位置上涉及多个灾难性的崩溃。在这里，我们讨论来自经过充分研究，地质年轻且活跃的岩浆系统的五个示例：科斯－尼西罗斯火山群（希腊），长谷（美国），坎皮·弗莱格雷（意大利南部），拉包尔（巴布亚新几内亚）和奥卡塔那（新西兰），以便深入了解火山口系统在大型爆炸爆发的建立和恢复过程中的内部运作情况。我们表明，破火山口岩浆系统是通过一系列过程演化而成的，这里统称为“破火山口循环”，这是单环和多环破火山口所共有的。就多环火山口而言 它们伴随着从一个破火山口的爆发到下一个破火山口的转变。破火山口循环包括（1）塌陷前活动的时期（潜伏期，成熟，岩浆挥发相的广泛存在），（2）灾难性破火山口形成（CCF）爆发和（3）塌陷后恢复（死灰复燃，再次爆发，随后的成熟）或周期的终止。潜伏期对应于地壳的热成熟期，在此期间，由于储层的生长能力有限，喷发频繁且体积小。在成熟阶段，岩浆储层逐渐生长，合并，均质，岩浆分化，喷发频率降低。一旦溶解的岩浆挥发相连续存在于储层中，系统便转变为发酵阶段，从而增加了岩浆的可压缩性并促使储层失控生长。发酵阶段结束时的CCF喷发可能是多种岩浆作用（包括岩浆充注，挥发性溶出和晶体糊状重熔）对储层加压的结果，而外部因素（例如构造作用）也可能起一定作用。 。即使岩浆供应减少，火山后火山喷发，火山下侵入和热液活动通常也会继续。但是，如果深处的岩浆供应仍然充足，则系统可能会恢复，最初喷出的是CCF储集层和/或新的充注岩浆，然后才恢复原状，直到浅层储集层开始生长并再次成熟。在此框架内将全球其他火山口放置在该框架内将能够测试所提议框架的稳健性，加深对控制周期持续时间及其各个阶段的因素的了解，并改善该州所特有的岩石学，地球物理和动荡症状一个系统。