Complex sentence: Indirect studies found that the magma chamber is located about underground, which matches the estimated depth of the Cretaceous Period rock in the oceanic lithosphere; this may indicate that the lithosphere acts as a lid on melting by arresting the magma's ascent.
Split into simpler sentences: Indirect studies found that the magma chamber is located about underground, which matches the estimated depth of the Cretaceous Period rock in the oceanic lithosphere. This seeming coincidence may indicate that the lithosphere acts as a lid on melting by arresting the magma's ascent.