Shallowly dipping (<30°) low‐angle normal faults (LANFs) have been documented globally; however, examples of active LANFs in continental settings are limited. The western margin of the Panamint Range in eastern California is defined by a LANF that dips west beneath Panamint Valley and has evidence of Quaternary motion. In addition, high‐angle dextral‐oblique normal faults displace middle to late Quaternary alluvial fans near the range front. To image shallow (<1 km depth), crosscutting relationships between the low‐ and high‐angle faults along the range front, we acquired two high‐resolution P wave seismic reflection profiles. The northern, 4.6‐km‐long profile crosses the 2‐km‐wide Wildrose graben and the southern, 0.8‐km‐long profile extends onto the Panamint Valley playa, ~7.5 km S of Ballarat, CA. The profile across the Wildrose graben reveals a robust, low‐angle reflector interpreted to represent the LANF separating Plio‐Pleistocene alluvial fanglomerate and Proterozoic metasedimentary deposits. High‐angle faults interpreted in the seismic profile correspond to fault scarps on Quaternary alluvial fan surfaces. Interpretation of the reflection data suggests that the high‐angle faults vertically displace the LANF up to 80 m within the Wildrose graben. Similarly, the profile south of Ballarat reveals a low‐angle reflector, which appears both rotated and displaced up to 260 m by high‐angle faults. These results suggest that near the Panamint range front, the high‐angle faults are the dominant active structures. We conclude that at least at shallow (<1 km) depths, the LANF we imaged is not active today.

中文翻译：

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东加利福尼亚低角度Panamint正断层系统的地震反射成像

全局记录了浅倾角（<30°）的低角度法向断层（LANF）。但是，大陆性活动LANF的示例是有限的。加利福尼亚东部Panamint山脉的西缘由LANF定义，该LANF向西浸入Panamint山谷下方，并具有第四纪运动的证据。此外，大角度右斜斜正断层将中，晚期第四纪冲积扇驱赶到射程前沿附近。为了成像浅（<1 km深度），低角度断层和高角度断层之间沿剖面前沿的横切关系，我们获取了两个高分辨率P波地震反射剖面。北部长4.6公里的剖面与2公里宽的Wildrose grab形交叉，而南部长0.8公里的剖面则延伸至加利福尼亚州巴拉瑞特市南约7.5公里的Panamint谷滩。野玫瑰grab上的剖面显示出一个坚固的低角度反射镜，该反射镜被解释为代表了区分上新世冲积扇状沉积物和元古生代沉积沉积物的LANF。地震剖面中解释的高角度断层对应于第四纪冲积扇面的断层陡峭度。反射数据的解释表明，高角度断层在Wildrose en片内使LANF垂直移动达80 m。同样，巴拉瑞特（Ballarat）以南的剖面显示出一个低角度反射器，该反射器在高角度断层的作用下旋转并位移至260 m。这些结果表明，在Panamint范围前缘附近，高角度断层是主要的活动构造。我们得出的结论是，至少在浅深度（<1 km），我们成像的LANF今天不活跃。