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在华盛顿州沿图特尔河北支的圣海伦斯山火山泥石流沉积中测量了11个点的碎屑产状,施密特网表明,碎屑组构呈现出弱的单峰型.本文用特征值方法将火山泥石流的碎屑组构与曾报导过的冰川底碛和较小型泥石流组构作了定量对比,计算出特征向量V_1(最大集中轴)和V_3(最小集中轴即长轴所在择优平面的极点)以及它们各自的强度S_1和S_3.S_1和S_3值与冰川底碛的相比要弱,但与小型泥石流的相似.尽管如此,火山泥石流组构还是能够从特征向量V_1和V_3的定向上与小型泥石流组构区别开来.第一,统计表明火山泥石流的V_1s明显地向上游倾斜,而小型泥石流的V_1s却没有优选倾斜方向;第二,火山泥石流的V_1与局部水流流向方位角的平均绝对差值比小型泥石流的要大得多,表明火山泥石流组构主要趋向于横向定向,特别是那些碎屑支撑的样品;第三,火山泥石流组构V_1的平均倾角明显大于小型泥石流中的V_1的平均倾角;第四,火山泥石流组构中V_3的平均倾角明显小于小型泥石流中V_3的平均倾角,这表明泥石流沉积中碎屑的长轴所在择优平面明显陡倾,特别是那些基质支撑的样品.火山泥石流组构也能从V_1和V_3的平均方位角上与冰川底碛区分开来.本文提出的碎屑组构与以前提出的假设相比,对于显示泥石流沉积学的特性可能是更有用的性质.
Eleven points of debris formation were measured in the volcanic debris flow deposition in the St Helens Mountains in the northern branch of the Tout River in Washington State and the Schmidt network shows that the detrital fabric exhibits a weak unimodal pattern. The value method quantitatively compares the detrital structures of the volcanic debris flow with those of the reported glacial bottom moraine and the smaller debris flow, and calculates the eigenvectors V_1 (maximum concentration axis) and V_3 (the minimum concentration axis, ie, the predominance of the long axis Plane poles) and their respective intensities, S_1 and S_3.S_1 and S_3 values are weaker than the glacial bottom moraine but similar to those of the small debris flows, although volcanic debris flow configurations can still be characterized from the eigenvectors V_1 and V_3 The results show that the V_1s of volcanic debris flows obviously incline to the upper reaches, while the V_1s of small debris flows do not have the preferred inclination direction. Second, V_1 of volcanic debris flow and azimuth of local water flow Is larger than that of small debris flow, indicating that the volcanic debris flow tectonics mainly tends to be oriented in the horizontal direction, especially those samples supported by debris. Thirdly, the average inclination angle of volcanic debris flow structure V_1 The average inclination angle of V_3 in volcanic debris flow is obviously smaller than the average inclination angle of V_3 in small debris flow, which indicates that the preferred plane of major axis of debris in sediment flow is obviously steep, Especially those that are supported by the matrix.The volcanic debris flow structure can also be distinguished from the glacial bottom moraine from the mean azimuths of V_1 and V_3.The detrital fabric proposed in this paper is much better than the previously proposed hypotheses The characteristics of learning may be more useful properties.