Journal of Asian Earth Sciences 29 (2007) 532–544 www.elsevier.com/locate/jaes Acoustical facies analysis at the Ba Lat delta front (Red River Delta, North Vietnam) G.D van den Bergh a a,* , Tj.C.E van Weering a, J.F Boels b, D.M Duc c, M.T Nhuan c Royal Netherlands Institute for Sea Research (NIOZ), P.O Box 59, 1790 AB Den Burg, Texel, The Netherlands b NAM, Scheperstraat 2, 9405 TA Assen, The Netherlands c Ha Noi University of Science, 334 NguyenTrai, Thanh Xuan, Ha Noi, Viet Nam Received June 2003; received in revised form 21 February 2006; accepted March 2006 Abstract A shallow penetrating, high-resolution acoustic study was performed in the Ba Lat delta, the major distributary of the Red River System in Northern Vietnam An acoustic facies map was constructed and the various facies types were validated through analysis of bottom sediments, by a study of gravity cores collected at 22 stations Analysis of the acoustic profiles and gravity cores revealed the presence of an asymmetrical, S to SW prograding prodelta lobe, in accordance with the prevailing longshore currents to the S The southern part of this prodelta is detached from the protruding Ba Lat delta front The prodelta is dominated by muddy sediments with minor thin (