New magnetic anomaly map for the Red Sea reveals transtensional structures associated with rotational rifting

Abstract

AbstractThe Red Sea is a modern analogue for studying continental break-up. Particularly, the Red Sea shows along-strike variability in the architecture, magmatism and associated style of rifting. In order to study these variabilities, continuous geophysical data that cover the entire length of the basin is desired. Our study aims to produce a continuous, reliable and robust magnetic anomaly map for the Red Sea. We present a new magnetic anomaly map for the Red Sea, derived from re-processing of shipborne data, merged and conformed to a recent satellite model, LCS-1. The new magnetic map reveals prominent patterns of magnetic anomalies in sub-perpendicular directions to the Red Sea, with a northward increase in obliquity. We provide further analysis for the magnetic data and associate sets of magnetic trends with transtensional basement structures. Directional analysis suggests a gradual increase in shear component along the Red Sea. The magnetic trends are coaxial with independent indicators of finite and instantaneous strains, and thus implies that these structures and their variability are related to the kinematic framework of the rift. We discuss the consequences of rifting close to the Euler pole, i.e. rotational rifting, and argue that both passive and active forces can explain an increased along-strike transtension, and accordingly the associated variability along the Red Sea.