# Geometry and Kinematics of the Central Fault Zone, Fula Sag, Central Africa Shear Zone
## 6 Growth Analysis of the Main Faults  
Based on the fault-plane throw analysis of the main faults in the CFZ in our previous analysis, we used the maximum throw subtraction method to quantitatively study the growth process of each fault segment so as to recover fault segmentation growth of the entire fault zone. Fault F\({}_{1}\) is segmented into four segments, including F\({}_{1-1}\), F\({}_{1-2}\), F\({}_{1-3}\), and F\({}_{1-4}\), which have been active since the Darfur period. All four segments were in the isolated growth stage during the Darfur period (the syn-rift phase of the second rifting, Figure 6c), and the synthetic-approaching transfer zones were developed among these fault segments. During the Amal period (the post-rift of the second rifting, Figure 6b), F\({}_{1-1}\) and F\({}_{1-2}\), F\({}_{1-2}\) and F\({}_{1-3}\) started to overlap each other and entered the soft-linkage stage, and the synthetic-overlapping transfer zones were developed among these fault segments; lateral growth narrowed the distance between F\({}_{1-3}\) and F\({}_{1-4}\), but they were still in the isolated growth stage and developed a synthetic-approaching transfer zone. During the Senna-Zeraf period (the third rifting, Figure 6a), four fault segments grew rapidly, with all entering the hard-linkage stage and eventually developing a fully grown, large fault. Figure 6: Relation between fault throw and extension distance of fault F\({}_{1}\). These plots illustrate the growth process of the fault F\({}_{1}\), indicating that the four originally separate fault segments constituting the fault F\({}_{1}\) became active during the Darfur period, entered the soft-linkage stage during the Amal period, and progressed to the hard-linkage stage during the third rifting, eventually forming a fully grown, large fault. Fault F3 is segmented into four fault segments, consisting of F3-1, F3-2, F3-3, and F3-4, all of which have been active since the Darfur period. During the Darfur period (the syn-rift phase of the second rifting, Figure 7c), all four segments were in the isolated growth stage, and the synthetic-approaching transfer zones were developed among these fault segments. During the Amal period (the post-rift of the second rifting, Figure 7b), fault F3-3 and fault F3-4 entered the soft-linkage stage, and the synthetic-overlapping transfer zone was developed between them; fault F3-1 and fault F3-2, and fault F3-2 and fault F3-3 began to connect initially at the top of the Bentiu Formation, indicating that the above two pairs of faults will soon enter the soft-linkage stage. During the Senna-Zeraf period (the third rifting, Figure 7a), four fault segments grew rapidly, with all entering the hard-linkage stage and eventually developing a fully grown, large fault. Fault F2 is segmented into three fault segments, from F2-1, F2-2 to F2-3. Fault F2-2, fault F2-1, and fault F2-3 have been active since the Bentiu period, the Darfur period, and the Amal period, respectively. Fault F2-2 grew active during the Bentiu period (the post-rift phase of the first rifting, Figure 8d), while its activity intensity appeared to be weak with a maximum throw value of merely 10 ms; fault F2-1 became active during the Darfur period (the syn-rift phase of the second rifting, Figure 8c), and was in the middle of an isolated growth, developing a synthetic-approaching transfer zone with fault F2-2. During the Amal period (the post-rift phase of the second rifting, Figure 8b), fault F2-3 became active, and it was then in isolated growth phase with fault F2-2, while at the top of the Bentiu Formation, fault F2-1 and fault F2-2 became connected, marking the beginning of their soft-linkage phase and the development of a synthetic-overlapping transfer zone. These three fault segments saw rapid growth during the Senna-Zeraf period (the third rifting, Figure 8a), with all of them entering the hard-linkage phase, eventually giving rise to a fully grown, large fault. Figure 7: Relation between fault throw and extension distance of fault F3.