Meanders: by erosion and deposition, middle and lower courses
1) current is faster on outside of bend as channel is deeper so less friction.
2) so more erosion takes place on outside of bend. River cliffs formed.
3) current slower on inside as channel is shallowerso more friction.
4) so eroded material deposited. Slip off slope formed.
Ox-Bow lakes: formed from meanders as they get bigger
1) erosion causes outside bends to get closer..
2) ..until only small bit of land left betwee (neck)
3) river breaks through this land (usually during flood)..
4).. and river flows alog shortest course.