Abstract Establishing the factors that control the pathways of magma ascent is an important issue in the study of monogenic mafic volcanism since it provides information about the relationship between the source of the ascending magma and the regional and local tectonic frameworks. We have quantitatively analyzed the spatial distribution of the volcanic centers in the monogenic volcanic fields (MVFs) of the Southern Puna using Nearest-Neighbor Analysis to assess the degree of randomness between individual centers. We also performed alignment analysis which highlights the structural weaknesses that magmas use to ascend. We integrate these novel data with published structural, petrologic, and geophysical data to propose a source-to-surface model which explains the spatial distribution of monogenic mafic centers of the Southern Puna. We find that MVFs display two distinct spatial patterns related to different magmatic production rates. Specifically, in those areas where the magmatic production is long-lasting and relatively high, the magma exerts strain rates suffciently high to reactivate pre-exisiting discontinuities with random orientations with respect to the current local stress conditions. As a result the volcanic centers are arranged with a clustered spatial distribution. We define these as MVFs controlled by magmatism or high flux fields (MVFs-M). On the other hand, low magmatic production rates tend to produce areas where mafic centers display a Poisson distribution, because strain rates are only sufficient to reactivate pre-existing discontinuities that are nearly parallel to the maximum compressive stress. This latter group is defined as MVFs controlled by tectonism or low flux fields (MVFs-T). Available petrological and geophysical data indicate that both groups are fed by a complex lower crustal MASH zone where magma production is associated with lithospheric foundering and subduction-related mantle melting. Spatial distribution of the MVFs in the Southern Puna are also affected by the development of upper crustal magma storage zones.

中文翻译：

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阿根廷普纳南部镁铁质单源火山作用的定量空间分布分析：对岩浆生产速率和上升过程中的结构控制的影响

摘要 确定控制岩浆上升路径的因素是单核基性火山作用研究中的一个重要问题，因为它提供了有关上升岩浆来源与区域和局部构造框架之间关系的信息。我们使用最近邻分析法定量分析了南普纳单核火山区 (MVF) 中火山中心的空间分布，以评估各个中心之间的随机性程度。我们还进行了排列分析，突出了岩浆用于上升的结构弱点。我们将这些新数据与已发表的结构、岩石学和地球物理数据相结合，提出了一个源到地表模型，该模型解释了普纳南部单核基性岩中心的空间分布。我们发现 MVF 显示出与不同岩浆生产速率相关的两种不同的空间模式。具体而言，在那些岩浆生产持续时间较长且相对较高的地区，岩浆施加足够高的应变率以重新激活预先存在的不连续性，并且相对于当前的局部应力条件具有随机方向。因此，火山中心排列成簇状的空间分布。我们将这些定义为由岩浆作用或高通量场 (MVFs-M) 控制的 MVF。另一方面，低岩浆生产速率往往会产生基性岩中心显示泊松分布的区域，因为应变速率仅足以重新激活几乎平行于最大压应力的预先存在的不连续性。后一组被定义为受构造运动或低通量场 (MVFs-T) 控制的 MVF。现有的岩石学和地球物理数据表明，这两个群体都受到复杂的下地壳 MASH 带的馈送，其中岩浆产生与岩石圈沉没和俯冲相关的地幔熔化有关。上地壳岩浆储存带的发育也影响了普纳南部MVFs的空间分布。