Appraisal of gravity-based lineaments around Central Indian Ridge (CIR) in different geological periods: Evidence of frequent ridge jumps in the southern block of CIR

Abstract

• Application of edge Enhancement to mark the lineaments over the CNIR. • Power spectrum analysis to differentiate long and short lineaments. • Comparison of spreading rate with length of lineaments. • Analysis of lineament orientation and plate movement in different geologic era. • Southern CNIR witnessed frequent ridge jumps for stability of the RTJ . This paper presents an approach for utilizing the balanced edge detection technique in satellite-derived gravity data to study the tectonic movement in past geological periods. The research is initiated by examining the normalized total horizontal derivative (NTHD) edge detection technique based on a moving window. NTHD is found to be effective for both shallow and deep-seated bodies. The noise in the gravity map could be effectively eliminated using a larger window size. The lineaments are marked over the Central Indian Ridge (CIR) using NTHD. Analysis of various geological periods and the lineaments shows that the speed and direction of the tectonic Plate play an essential role in deciding the length and orientation of lineaments formed. The most prominent lineament pattern observed over the CIR is in the NE-SW, ENE-WSW, and NNE-SSW, possibly associated with plate movement during Late Cretaceous to Late Eocene and after the Early Miocene period. In addition, a few lineaments are also found to be oriented in NW-SE, E-W, and N-S. The N-S lineaments might be the consequence of the movement of the Indian Plate in a northward direction for a short time during the Late Eocene and Early Miocene. The E-W lineaments result from the transfer of the Reunion hotspot from the Indian to the African Plate. The high lineament density and circular statistical values indicate left flank of the CIR undergoes rigorous tectonic activity. The high value of circular statistics indicates the chaotic arrangement of lineaments in the southern block of the CIR.