Abstract: An assembly for initiating a detonating explosive charge, e.g., a surface seismic charge, by low-energy detonating cord (LEDC) has a cord-connector fitted around a percussion-actuated detonator or booster, and a means of piercing a frangible package to enable the assembly to be embedded in the charge. In a preferred assembly, the connector is a plastic tube which fits over the actuation end of a booster shell whose opposite end is notched or serrated. A detonator preferably is fitted in a plastic cord-connecting tube whose end surface is tapered, or which has a pointed extension member, forming a spike. LEDC does not pose the fire hazard encountered with heavier cords in surface seismic operations in wooded or grassy areas.