Mobile has very little memory. Lots of DOM elements will cause a slow down. Reduce the DOM elements and styles might help.
I'd first remove all the CSS to see if that speeds it up. box-shadows and border-raduis can use a lot of the processor. Other items might be slowing it down a lot.
Also you can use the timeline in Safari 6.1 or Chrome dev tools to see how many times you are recalculating the styles and repainting the screen. repainting too much will also slow it down a lot.
The really way to get fast scrolling on mobile is to do a lot of custom optimizations for the browser, DOM, network and garbage collector. Check out the code for PerfView to see some of the optimizations (https://github.com/puppybits/BackboneJS-PerfView).