Global systematics of arc volcano position
Global systematics of arc volcano position
复制标题
全球弧火山位置系统学
作者：
P. England;R. Katz
源自Grove， T. et al. 459 694-697 (2009)10.1038/nature08044；在俯冲带之上的火山弧位置的全球系统被广泛认为是发生在深部的熔融过程的线索，而火山弧的位置通常用俯冲板块顶部附近的含水流体的释放来解释（例如，参见文献3-6）。Grove等人得出结论，弧火山的位置是由地幔中熔融控制的，温度高于饱和水的上地幔固相，低于矿物绿泥石的稳定性上限，特别是弧锋位于地幔中这种熔融区域的最浅点的正上方。在这里，我们表明这个结论是不正确的，因为Grove等人计算出的弧位置是错误的，这是由于他们的数值模型的空间分辨率不足，而且因为他们在预测和观测系统之间发现的一致性源于计算出的弧位置和板倾角之间的虚假相关性。从他们的实验中得出的一个更有意义的结论是，绿泥石稳定性的极限（参考文献7中的图1b）不能解释在急剧定位的弧锋下的板块深度的全球系统。
Arising from Grove, T. et al. 459 694–697 (2009)10.1038/nature08044; Grove et al. replyGlobal systematics in the location of volcanic arcs above subduction zones are widely considered to be a clue to the melting processes that occur at depth, and the locations of the arcs have often been explained in terms of the release of hydrous fluids near the top of the subducting slab (see, for example, refs 3–6). Grove et al. conclude that arc volcano location is controlled by melting in the mantle at temperatures above the water-saturated upper-mantle solidus and below the upper limit of stability of the mineral chlorite and in particular, that the arc fronts lie directly above the shallowest point of such melt regions in the mantle. Here we show that this conclusion is incorrect because the calculated arc locations of Grove et al. are in error owing to the inadequate spatial resolution of their numerical models, and because the agreement that they find between predicted and observed systematics arises from a spurious correlation between calculated arc location and slab dip. A more informative conclusion to draw from their experiments is that the limits of chlorite stability (figure 1b of ref. 7) cannot explain the global systematics in the depth to the slab beneath the sharply localized arc fronts.