Is there any difference between weathering and erosion?

Weathering is a general term for all effects of weather. Erosion refers to any removal of material, which may be caused by wind borne sand, acid rain, ground water, or several other processes.

Here in the Arizona desert we have a weathering process we call "desert varnish". A rock will turn dark brown on the exposed side, caused by ADDITION of material, not erosion. The occasional rain spatters dust onto the rock and the sun then bakes it. The thickness is regular and can be measured to determine how long the rock has been exposed.
Pictures: www.google.com/search?site=&tbm=isch&source=hp&biw=1021&bih=738&q=desert+varnish
Article: en.wikipedia.org/wiki/Desert_varnish