Focused and diffuse extension in controls of ocean ridge segmentation in analogue models

Abstract

This work aims to provide insights into the initiation and evolution of segments along ocean ridges as they propagate and mature. It is based on the results of analogue modeling performed in a centrifuge with applied acceleration of gravity force. The effect of the varied degree of extension allowed during propagation of analogue ridge results in segments being focused along the ridge axes or widely distributed within the entire axial zone. Three distinct types of segment interaction are documented, controlled by the relative distribution and orientation of interacting segments and leading to the development of linear ridges, overlapping spreading centers, and oblique transform zones. The importance of the initial distribution of segments in the ridge evolution inferred in the models suggests its significance for formation of natural ridges whose mature configurations must be largely inherited from that of spreading centers formed in the early stages of focused or diffuse extension.