Abstract We present a detailed stratigraphy of the Coranzuli caldera-forming deposits. This caldera, located in the Altiplano-Puna Volcanic Complex (Central Andes), generated four ignimbrite deposits with similar field characteristics and facies that differ from each other in, above all, the nature of the lithic fragments they contain. Three different lithofacies (fine-grained cross-stratified facies, massive lithic breccia facies and massive ignimbrite facies) are found in all the ignimbrite deposits, which occasionally also contain a lenticular lithic-rich facies and/or a pumice-rich facies. These field characteristics and, in particular, local deposit thicknesses were used to develop a theoretical model of the dynamics and emplacement mode of the Coranzuli pyroclastic flows. Our results show that these ignimbrites were emplaced by dense pyroclastic density currents subjected to high accumulation rates and velocities, thereby indicating rapid en masse emplacement that was also influenced by local paleotopography as deduced from facies analysis.

中文翻译：

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Coranzulí ignimbrites (Central Andes) 的特征和侵位机制

摘要 我们提供了 Coranzuli 火山口形成矿床的详细地层。这个火山口位于 Altiplano-Puna 火山复合体（安第斯山脉中部），产生了四个具有相似场特征和相的熔凝岩沉积物，尤其是它们包含的岩屑碎片的性质不同。在所有的凝灰岩矿床中都发现了三种不同的岩相（细粒交错层理相、块状岩屑角砾岩相和块状凝灰岩相），偶尔还含有透镜状富岩相和/或富浮石相。这些油田特征，特别是局部沉积物厚度，被用来开发 Coranzuli 火山碎屑流的动力学和侵位模式的理论模型。