New criteria for systematic mapping and reliability assessment of monogenetic volcanic vent alignments and elongate volcanic vents for crustal stress analyses
New criteria for systematic mapping and reliability assessment of monogenetic volcanic vent alignments and elongate volcanic vents for crustal stress analyses
复制标题
用于地壳应力分析的单成因火山喷口排列和细长火山喷口的系统制图和可靠性评估的新标准
DOI：
10.1016/j.tecto.2009.08.025
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发表时间：
2010
期刊：
影响因子：
2.9
通讯作者：
T. Wilson
中科院分区：
文献类型：
--
作者：
T. Paulsen;T. Wilson
单生火山喷口排列的线性排列是地球和其他行星火山区应力/应变数据的重要来源。然而，目前还没有用于绘制喷口对准或评估对准可靠性的标准方法，这对于根据喷口对准确定稳健的应力基准至关重要。在这里，我们定义了一种系统的方法，通过绘制喷口的位置和形状来定义单生喷口对齐。喷口向椭圆形的伸长与控制对齐的地下裂隙的走向直接相关。因此，细长的喷口对于确定可靠的区域喷口对齐至关重要，也提供了一种评估应力方向的独立手段。我们的通风口对齐可靠性评估系统(A&>；B&>；C&>D)基于通风口的数量、通风口中心点与最佳配合线的标准偏差、细长通风口的数量和类型、椭圆形通风口与最佳配合线的长轴的标准偏差，以及在对齐缺少细长通风口的情况下，根据通风口间距。我们量化了来自多成因火山和台地火山田的明确的裂隙供给喷口排列的形态计量参数，以建立可靠性评估的适当阈值。在这种新方法中，对喷口位置和形状的联合分析优化了定位图的绘制过程和将纳入应力分析的定位的可靠性评估。我们为从可靠性评估的通风口对齐和细长通风口获得的应力数据提供质量评级方案。我们通过分析平台火山场(亚利桑那州的旧金山火山场)和多成因火山(南极洲的莫宁山)侧翼的火山场，展示了这种新的测绘和评估方法的实用性。
Linear arrays of monogenetic volcanic vent alignments represent an important source of stress/strain data from volcanic regions of the Earth and other planets. Currently, however, there is no standard methodology for mapping vent alignments or for assessing alignment reliability, which are essential to defining a robust stress datum from vent alignments. Here we define a systematic method for defining monogenetic vent alignments by mapping the locations and shapes of vents. Elongation of vents into elliptical shapes is directly related to the trend of subsurface fissures that control alignments. Elongated vents therefore are critical for defining reliable regional vent alignments, and also provide an independent means for assessing stress directions. Our reliability assessment system (A>B>C>D) for vent alignments is based on the number of vents, the standard deviation of vent center points from a best-fit line, the numbers and types of elongate vents, the standard deviation of long axes of elliptical vents from a best-fit line, and, in cases where alignments lack elongate vents, by vent spacing distances. We quantified morphometric parameters of well-defined fissure-fed vent alignments from polygenetic volcanoes and platform volcanic fields to establish appropriate threshold values for reliability assessments. In this new method, the combined analysis of vent locations and shapes optimizes the process of alignment mapping and the assessment of the reliability of alignments to be incorporated in stress analyses. We provide quality-ranking schemes for stress data derived from reliability-assessed vent alignments and from elongate vents. We demonstrate the utility of this new mapping and assessment methodology by analyzing monogenetic cinder cone fields within a platform volcanic field (the San Francisco volcanic field in Arizona) and within a volcanic field on the flank of a polygenetic volcano (Mount Morning in Antarctica).