I'd first question whether you need global navigation on mobile. I'm often asked to implement global navigation on projects because project leads have a belief that users want to 'hand out' in the application and be able to navigate from one point to any other point.
But in terms of actual usage, that's not now most people interact with most applications--at least on mobile. A hub-and-spoke model of navigation tends to work a lot better. If they want to navigate somewhere else, a tap on 'back' or 'home' to get to the main navigation is typically preferred for a couple of reasons:
- navigating 'back' or 'up' on a mobile device tends to be rather trivial (tap or swipe)
- it frees up valuable real-estate on the task-driven pages--which are typically the primary objective of the user.
- on a lot of mobile apps, people want to come in, finish a task, and be done. They don't need to navigate freely from any one page to another.
Looking at your sample images, I'm not entirely clear what you consider to be the main vs. secondary navigation. They also appear to be wide pages (so not sure I understand the mobile-centric part).
That said, consider the many different ways to present navigation on a mobile device...swipe-to-show-nav-beneath, footer icons, swipe-to-open panels, etc.
Based on your comments, here's one suggestion. This removes the global menu for a 'hub and spoke' model (back) and the activate menu moved to the title bar:
download bmml source – Wireframes created with Balsamiq Mockups