MusicTechHelpGuy breaks down Logic 11's Chord Track and how it interacts with Apple Loops that carry region chords.
Drag in a loop like Analog Infinity, and Logic automatically pushes its chord progression up into the Chord Track. That's useful for session players, but not always what you want.
You can view and delete unwanted chord data by opening global tracks (press G) and clicking directly on the chord entries.
To stop the auto-import, select Keep Region Chords in the loop browser before dragging the loop in. The chords stay attached to the region without cluttering the Chord Track.