## 5 Discussion  
### Activity and Distribution of the Wangjiabian-Houjiawan Fault  
To assess the activity characteristics of the Wangjiabian-Houjiawan Fault (F1-1a), a few fault displacements in the Late Pleistocene were updated from previous studies according to the field investigations and consultation with a member of the \"Active Fault Detection and Seismic Hazard Assessment in Xi\"an City\" project. The updated and the newly discovered fault displacements in the Late Pleistocene are shown in Table 3 by the numbers 22, 34-38 and 43. During the Late Pleistocene, the Wangjiabian-Houjiawan Fault (F1-1a) yielded vertical offsets of 1.5-2 m in the Bailu Loess Tableland and Shenhe Loess Tableland, with no displacement in the Shaoling Loess Tableland. We thus concluded that the Wangjiabian-Houjiawan Fault (F1-1a) is Late Pleistocene active in general, while the activity is relatively weaker in the Shaoling Loess Tableland. Figure 6: Photographs of the profiles in the foundation pit. (**a**–**h**) Photographs of Profiles P1–P8. (**i**,**j**) Photographs of Profiles P9. (**k**–**p**) Photographs of Profiles P10–P16. The profile locations are shown in Figure 5a. The arrows in the photographs point to the paleosol S1. The micro-topographic profile in this area was acquired using GPS RTK data. These data were collected along the shallow seismic reflection survey line (Figure 2b), which reveals that the relief of the surface scarp is close to 35 m. Subsequently, the fault was  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Geomorphic Unit**} & \multirow{2}{*}{**Fault Name**} & \multirow{2}{*}{**Location**} & \multirow{2}{*}{**Number**} & \multicolumn{2}{c}{**Displacement**} & \multirow{2}{*}{**Maximum**} & \multirow{2}{*}{**Average**} \\  & & & & & **and References** & & \\ \hline \multirow{8}{*}{Tongren Leoss Tableland} & \multirow{8}{*}{Majie–Nianwan Fault (F1-1)} & Majie & 1 & 1 [7] & & \\ \cline{3-6}  & & Yangpo & 2 & 1 [2] & & \\ \cline{3-6}  & & Xiaoya & 3 & / [7] & & \\ \cline{3-6}  & & Chezhanggou & 4 & 1.5 [4] & & \\ \cline{3-6}  & & Yuejagou & 5 &? [7] & & \\ \cline{3-6}  & & Xiaogou & 6 & / [7] & & \\ \cline{3-6}  & & Fault (F1-2) & Huijagou & 7 & 1.5 [7] & & \\ \cline{3-6}  & & Wangkezhai & 8 & 0.8 [7] & & \\ \cline{3-6}  & & Lijiangou & 9 & 0.3 [4] & & \\ \cline{3-6}  & & Yangiazhai & 10 & 0.5 [7] & & \\ \cline{3-6}  & & Fangiacun & 11 & / [7] & & \\ \cline{3-6}  & & Zhongdicum-Tangiazhai Fault (F1-2a) & Zhongdicum & 12 & 2 [7] & & \\ \cline{3-6}  & & Renjacun & 13 & / [7] & & \\ \cline{3-6}  & & Xiangyang Company & 14 & 0.4 [7] & & \\ \hline \multirow{8}{*}{Majie–Nianwan Fault (F1-1)} & \multirow{8}{*}{Majie–Nianwan Fault (F1-1  
projected onto the topographic profile, revealing its position ranging from approximately one-third to one-half of the scarp from low to high. Previous studies had identified that the scarp was a result of both faulting and erosion [3; 22]. Late Quaternary Activity Characteristics and Geological Significance of the Lintong-Chang'an Fault Zone  
The displacement data from the Late Pleistocene along the LCFZ were gathered, drawing on both prior and ongoing research efforts (Table 3). In the table, the \"Maximum value\" represents the sum of the maximum fault displacements on each branch fault, while the \"Average value\" represents the sum of the average displacements on each branch fault in the same geomorphic unit. In addition, Figure 7a shows the along-strike variations in fault slip within different geomorphic units referenced by the above data. The overall activity of the LCFZ has been relatively weak since the Late Pleistocene (Table 3 and Figure 7a). Fault outcrops with no displacements in the Late Pleistocene strata can be found in the Bailu Loess Tableland and the Shaoling Loess Tableland. Based on the average fault displacements of 0.92-8.03 m, and the bottom boundary age of 127 ka of the paleosol S1 (Table 1), the average slip rate on the fault zone is estimated to be 0.011-0.075 mm/a since the Late Pleistocene.