Varying estimates of both present-day strain accumulation and long-term slip rate on the Doruneh left-lateral strike-slip fault, NE Iran, have led to suggestions that it exhibits large along-strike and/or temporal changes in activity. In this study, we make and compare estimates of slip rate measured using both geodesy and geomorphology, and spanning time periods ranging from decadal to 100 ka. To image the present-day accumulation of strain, we process 7 years (2003–2010) of data from six ENVISAT tracks covering the fault, with interferograms produced for 400-km-long strips of data to image the long-wavelength signals associated with interseismic strain accumulation across the locked fault. Our analysis shows that less than 4 mm/yr—and likely only 1–3 mm/yr—of slip accumulates across the fault. Using high-resolution optical satellite imagery, we make reconstructions of displacement across six alluvial fans whose surfaces cross the fault, in four separate river catchments. We determine the ages of these fans using infra-red-stimulated luminescence dating combined with U-series dating of pedogenic carbonates. The six fans vary in age from ∼10– to 100 kyr, and a regression line fitted to four of these yields a slip rate of 2.5 ± 0.3 mm/yr. We conclude that within the uncertainty of our measurements, the slip rate has remained constant over the last ∼100 ka and is representative of the strain accumulation at the present-day. The slip rate that we measure is consistent with the E-W left-lateral Doruneh fault accommodating N-S right-lateral faulting by “bookshelf” faulting, with clockwise rotation about a vertical axis.

中文翻译：

---

伊朗 Doruneh 走滑断层的恒定滑动率，晚更新世、全新世和年代际时间尺度的平均值

对伊朗东北部 Doruneh 左旋走滑断层的当前应变积累和长期滑动速率的不同估计表明，它在活动中表现出较大的沿走向和/或时间变化。在这项研究中，我们制作并比较了使用大地测量学和地貌学测量的滑移率估计值，跨越了从十年到 100 ka 的时间段。为了对当今的应变积累进行成像，我们处理了来自覆盖断层的 6 个 ENVISAT 轨道的 7 年（2003-2010）数据，并为 400 公里长的数据带生成了干涉图，以对与跨锁定断层的地震间应变积累。我们的分析表明，小于 4 毫米/年——可能只有 1-3 毫米/年——的滑移累积穿过断层。使用高分辨率光学卫星图像，我们重建了六个冲积扇的位移，这些冲积扇表面穿过断层，在四个独立的河流集水区。我们使用红外刺激发光测年结合成土碳酸盐的 U 系列测年来确定这些扇的年龄。六个风扇的年龄从 10 到 100 kyr 不等，拟合其中四个的回归线产生 2.5 ± 0.3 毫米/年的滑移率。我们得出结论，在我们测量的不确定性范围内，滑移率在过去的 100 ka 中保持不变，并且代表了当今的应变积累。我们测量的滑动速率与 EW 左侧 Doruneh 断层一致，该断层通过“书架”断层作用适应 NS 右侧断层，绕垂直轴顺时针旋转。