摘要：
Field investigations show that the Seismogenic structure of Atushi MS8×1/4 earthquake occurred on the Tashpushta-Kalatag fault zone on August 22, 1902 in Xinjiang. The total rupture length was about 103 km long, along the general east-northeast-striking, southward thrust faults. The western boundary of surface rupture zone was mainly composed of north-northeast-striking, left-lateral strike-slip faults. The rupture was divided into 6 parts from west to east: Maximum horizontal and average displacement of 9. 1m and 6. 4m were observed along the Kayidaike fault characterized by left-lateral strike-slip faulting;A maximum horizontal and average displacement of 7. 1m and 5. 8 m occurred along the left-lateral strike-slip Sesikesayi fauThe 1902 scarp of the steeply-dipping thrust Tashpushta fault was 0. 5 ～ 3. 0 m in average height, a maximum vertical displacement of6. 4 m, partly consistent with maximum 6. 0 m of left-lateral slip;The coseismic scarp on the steeply-dipping thrust Kalatage fault was 4. 0 m in average height, and 8. 0 m in maximum height;The maximum vertical and average vertical displacement measured along the steeply-dipping thrust Tuogaitage fault was 2. 9 m and 3. 9 m;On the gentle-steeply thrust Kurutika fault the height of the average vertical and maximum vertical displacement was 0. 8 m and 2. 1m.The active tectonics in the southwestern Tianshan Piedmont, including the Tashpushta-Karatag thrust-fold belt and the Tashpushta-Atushi thrust-fold belt, were all camel-like structures belonging to the spreading tectonics in the northeastern margin of Pamir. The main tectonics was the Piedmont compression nappe of Tarim Basin toward the South Tianshan Mountains. Karatag and Atushi, two southward-dipping thrust faults, were the latest thin-skinned structures in the front of Pamir, which were rooted in a slip layer near the bottom of Neogene. The seismic fault on the south wing of the eastern segment of the Tashpushta anticline was exposed along the gypsum layer at the bottom of the Miocene, and the slippage layer of thin-skinned structure in the seismic area was probably composed of the gypsum layer.%野外调查表明1902年8月22日新疆阿图什8×1/4级地震发震构造为塔什普什塔—喀拉塔格断裂带, 总破裂长度约为103 km, 总体呈NEE走向, 以南倾逆断层为主, 西边界以NNE向左旋走滑断层为主.共分为6段, 自西向东包括:喀依代克段以左旋走滑水平运动为主, 平均水平位移量6.4m, 最大水平位移量为9.1 m;色斯克萨依段以左旋走滑水平运动为主, 平均水平位移量5.8 m, 最大水平位移量为7.1 m;塔什普什塔段以高倾角逆冲运动为主, 平均垂直位移量为0.5～3.0 m, 最大垂直位移量为6.4 m, 局部具有左旋走滑水平位移, 最大水平位移量为6.0 m;喀拉塔格段以高倾角逆冲运动为主, 平均垂直位移量为4.0 m, 最大垂直位移量8.0 m;托盖塔格段以高倾角逆冲运动为主, 平均垂直位移量为2.9 m, 最大垂直位移量3.9 m;库如提喀段以缓倾角逆掩运动为主, 平均垂直位移量为0.8 m, 最大垂直位移量2.1 m.西南天山山前活动构造包括塔什普什塔—喀拉塔格逆断层—褶皱带和阿图什逆断层—褶皱带, 均为背驼式构造, 隶属于帕米尔东北缘扩展构造, 主体构造表现为塔里木盆地向南天山山前挤压推覆.喀拉塔格与阿图什这两条南倾的逆断层在深部归根为一条近水平的新近系底部的滑脱层上, 属帕米尔前缘最新薄皮构造.在塔什普什塔背斜东段南翼的地震断层沿中新统底部的石膏层出露, 震区薄皮构造的滑脱层很可能由该石膏层组成.
