Notes from Lecture 5 – Tectonic Settings

Lecture 5 – Tectonic Settings

1. Introduction to Mid-Ocean Ridges and Seafloor Spreading

• Definition: Mid-ocean ridges are critical features in the study of plate tectonics and are recognized as the primary sites for the formation of new oceanic crust.

• Seafloor Spreading: This phenomenon involves the continuous addition of new crustal material to the edges of diverging tectonic plates.

1.1. The Mechanics of Ridge Push

• Ridge Push Mechanism: A significant factor driving the movement of tectonic plates, ridge push occurs as the newly formed oceanic crust glides atop the underlying asthenosphere. This movement is influenced by gravity, causing the plates to slide apart, furthering the divergence at mid-ocean ridges.

1.2. Defining the Ridge Axis

• Ridge Axis: The center line of a mid-ocean ridge, designated as the