most moving skins have static in the name, and are found in terrain.dsres. for example, b_t_xxx_rvr_static-simple ; moving lava skin. i also believe some of the skins, if not all, that have "dynamic" in the name, are moving aswell. for example, b_c_edm_ht-dynamic.
also check out skins like: b_t_for01_rvr_static and b_t_for01_rvr_fall-top-static as well as others.