A method of land surveying of subsurface formations in an area of interest with emission of seismic energy by a plurality of vibratory source groups, each vibratory source group comprising a plurality of swept frequency seismic energy sources emitting seismic energy for reception as blended seismic records at a fixed receiver array of seismic energy receivers deployed across a land survey area of interest, comprising the method the steps of: (a) locating the receivers of the array at fixed positions across the length and width of the area of interest; (b) locating the vibratory source groups in different individual sectors at initial vibrator source points along a shot line over the receiver spread spaced from other survey groups by an intergroup spacing distance along the shot line; (c) performing frequency sweeps to emit seismic energy from each seismic energy source in the vibratory source groups, performing a frequency sweep comprising each seismic energy source in individual ones of the vibratory source groups emitting seismic energy, at a different assigned frequency bandwidth from each of the other seismic energy sources in the same vibratory group, at a designated different but partially overlapping sweep length from each of the other sources in the same vibratory source group, and at different start times from the other sources in the same individual one of the vibratory source groups; (d) moving the vibratory source groups across the receiver array to successive ones of assigned vibrator source points; (e) repeating steps (c) and (d) until the vibratory source groups reach the end of their respective intergroup spacing; and (f) forming a blended seismic record at the receivers of the fixed array of the response of subsurface formations to the energy emitted in the frequency sweeps from the concurrently operating vibratory source groups at the successive ones of the assigned vibrator source points over the length of the intergroup spacing. (a) locating the receivers of the array at fixed positions across the length and width of the area of interest; (b) locating the vibratory source groups in different individual sectors at initial vibrator source points along a shot line over the receiver spread spaced from other survey groups by an intergroup spacing distance along the shot line; (c) performing frequency sweeps to emit seismic energy from each seismic energy source in the vibratory source groups, performing a frequency sweep comprising each seismic energy source in individual ones of the vibratory source groups emitting seismic energy, at a different assigned frequency bandwidth from each of the other seismic energy sources in the same vibratory group, at a designated different but partially overlapping sweep length from each of the other sources in the same vibratory source group, and at different start times from the other sources in the same individual one of the vibratory source groups; (d) moving the vibratory source groups across the receiver array to successive ones of assigned vibrator source points; (e) repeating steps (c) and (d) until the vibratory source groups reach the end of their respective intergroup spacing; and (f) forming a blended seismic record at the receivers of the fixed array of the response of subsurface formations to the energy emitted in the frequency sweeps from the concurrently operating vibratory source groups at the successive ones of the assigned vibrator source points over the length of the intergroup spacing.