Peculiarities of morphology and kinematics of the eastern segment in the Southwestern Indian Ridge between a Melville transform fault and triple junction zone Rodriges

Abstract

The eastern segment of the Southwest Indian Ridge is a unique wedge-shaped structure. The absence of transform faults in this region is explained by young age, anomalously low crustal power, and ultra slow spreading, at which spatial stresses are compensated by local fracture. The plan shows the presence of two fracture systems: one was probably caused by tensile stresses of global order associated with the movement of lithospheric plates, and the other is an evidence of local stretching processes. The clear longitudinal segmentation of the Southwest Indian Ridge was most likely caused by local planned transformanions that occurred during the wedge opening. Compilation of facts obtained during the voyage of the R/V «Akademik Nikolai Strakhov» and literature data allows us to conclude that the opening of the basin most likely follows the scenario of a passive compensatory gap initiated by the global geodynamic restructuring of the structural plan in the Indian Ocean.

Keywords

• wedge-shaped spreading basin
• South-West Indian Ridge
• triple junction Rodrigues