The pseudotachylyte of the Markagunt slide in Utah is the best example of gravity slide frictional melt. A key exposure near Panguitch provides opportunities to investigate the kinematics of frictional melts. Here we analyze the anisotropy of magnetic susceptibility (AMS) in eight oriented samples and show that magnetite dominates the magnetic susceptibility (97.7% in generation veins and 87.6% in injection veins) and most likely also the AMS. These rocks have magnetic susceptibility one order of magnitude greater (∼46,106 • 10⁻⁶ [SI]) than their host rock (∼1850 • 10⁻⁶ [SI]), which shows that magnetite must have formed during the gravity slide. The AMS of these rocks records the laminar flow kinematics of the frictional melt, with a North-South direction and a top-to-South sense of displacement consistent with regional observations. The dominantly planar symmetry of the AMS points to a flow regime dominated by pure shear, towards the end of the gravity slide movement. Our results, obtained on a landslide pseudotachylyte where the emplacement kinematics was already known, fundamentally validate the use and interpretation of AMS in other pseudotachylytes including those formed along seismogenic faults.

犹他州 Markagunt 滑道的假速凝液是重力滑道摩擦熔化的最好例子。Panguitch 附近的一次重要曝光为研究摩擦熔体的运动学提供了机会。在这里，我们分析了八个定向样品中磁化率 (AMS) 的各向异性，并表明磁铁矿在磁化率中占主导地位（在生成脉中为 97.7%，在注入脉中为 87.6%），并且很可能也是 AMS。这些岩石幅度较大的磁化率一个数量级（~46,106•10 ^-6 [SI]），比其围岩（~1850•10 ^-6[SI])，这表明磁铁矿一定是在重力滑动过程中形成的。这些岩石的 AMS 记录了摩擦熔体的层流运动学，具有南北方向和从上到南的位移感，与区域观测结果一致。AMS 的主要平面对称性指向以纯剪切为主的流态，接近重力滑动运动的末端。我们的结果是在已经知道侵位运动学的滑坡拟速带上获得的，从根本上验证了 AMS 在其他拟速带中的使用和解释，包括那些沿发震断层形成的拟速带。