Comprehensive high-resolution sidescan sonar imagery, swath bathymetry, and photographic data from the TAG rift valley (Mid-Atlantic Ridge, 26 ¿N) suggest significant asymmetry in crustal accretion. Discontinuities and asymmetry in structural and volcanic morphology and age distribution about the spreading axis suggest a recent episode of preferential accretion of crust to the east throughout the central 10 km of this spreading segment. Such episodes may contribute to the long-term spreading asymmetry in the area. ¿ American Geophysical Union 1996