The Google Ventures website at http://www.googleventures.com/ has interesting functionality -- when you scroll down the page, the upper "masthead" stays fixed to the window but is slowly covered up by the content below.
This is somewhat similar to parallax scrolling, but usually that involves multiple layers moving at varying speeds. In this case only one piece is moving.
Is this an established design pattern that has been named and used elsewhere? The best name my team could think of is "tectonic plates" but I doubt that is common terminology.