26 27 Azimuthal variations in receiver function conversions can image lithospheric structural 28 contrasts and anisotropic fabrics that together compose tectonic grain. We apply this 29 method to data from EarthScope Transportable Array in Alaska and additional stations 30 across the northern Cordillera. The best-resolved quantities are the strike and depth of 31 dipping fabric contrasts or interfaces. We find a strong geographic gradient in such 32 anomalies, with large amplitudes extending inboard from the present-day subduction 33 margin, the Aleutian arc, and an influence of flat-slab subduction of the Yakutat 34 microplate north of the Denali fault. An E-W band across interior Alaska shows low 35 amplitude crustal anomalies. Anomaly amplitudes correlate with structural intensity 36 (density of aligned geological elements), but are highest in areas of strong Cenozoic 37 deformation, raising the question of an influence of current stress state. Imaged 38 subsurface strikes show alignment with surface structures. We see concentric strikes 39 around arc volcanoes implying dipping magmatic structures and fabric into the middle 40 crust. Regions with present-day weaker deformation show lower anomaly amplitudes 41 but structurally aligned strikes, suggesting pre-Cenozoic fabrics may have been 42 overprinted or otherwise modified. We observe general coherence of the signal across 43 the brittle-plastic transition. Imaged crustal fabrics are aligned with major faults and 44 shear zones, while intra-fault blocks show imaged strikes both parallel to and at high 45 angles to major block-bounding faults. High-angle strikes are subparallel to 46 neotectonic deformation, seismicity, fault lineaments, and prominent metallogenic 47 belts, possibly due to overprinting and(or) coevolution with fault-parallel fabrics. We 48 suggest that the underlying tectonic grain in the northern Cordillera is broadly 49 distributed rather than strongly localized. Receiver functions thus reveal key 50 information about the nature and continuity of tectonic fabrics at depth and can 51 provide unique insights into the deformation history and distribution of regional 52 strain in complex orogenic belts. 53 54 55

中文翻译：

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使用可移动阵列接收器功能对北科迪勒拉造山带的构造颗粒进行成像

26 27 接收函数转换中的方位角变化可以成像岩石圈结构 28 对比和各向异性结构，它们共同构成了构造颗粒。我们将此 29 方法应用于来自阿拉斯加的 EarthScope 可移动阵列和横跨北科迪勒拉的其他站点 30 的数据。分辨率最高的数量是 31 种浸渍织物对比或界面的撞击和深度。我们在这 32 个异常中发现了强烈的地理梯度，从今天的俯冲 33 边缘、阿留申弧向内延伸的大振幅，以及德纳利断层以北的雅库塔特 34 微板块的平板俯冲的影响。横跨阿拉斯加内陆的 EW 波段显示出 35 振幅的低地壳异常。异常幅度与结构强度 36（对齐地质元素的密度）相关，但在新生代 37 变形强烈的地区最高，提出了当前应力状态影响的问题。成像的 38 次地下撞击显示与地表结构对齐。我们看到弧形火山周围的同心撞击 39，这意味着岩浆结构和结构浸入了 40 中部地壳。目前变形较弱的区域显示出较低的异常振幅 41 但结构上对齐的罢工，表明新生代前的织物可能已被 42 套印或以其他方式修改。我们观察到信号在 43 脆塑性转变中的总体一致性。成像的地壳结构与主要断层和 44 个剪切带对齐，而断层内块显示成像的走向与主要块边界断层平行和成 45 度角。大角度走向与 46 次新构造变形次平行，地震活动、断层线和突出的成矿 47 带，可能是由于叠印和（或）与断层平行结构的共同演化。我们 48 认为北科迪勒拉的下伏构造颗粒是广泛分布的，而不是强烈局部化的 49。因此，接收器函数揭示了有关深度构造结构的性质和连续性的 50 项关键信息，并且可以 51 提供对复杂造山带中区域 52 应变的变形历史和分布的独特见解。53 54 55 因此，接收器函数揭示了有关深度构造结构的性质和连续性的 50 项关键信息，并且可以 51 提供对复杂造山带中区域 52 应变的变形历史和分布的独特见解。53 54 55 因此，接收器函数揭示了有关深度构造结构的性质和连续性的 50 项关键信息，并且可以 51 提供对复杂造山带中区域 52 应变的变形历史和分布的独特见解。53 54 55