4000000 counts 100000 KEUFFEL & ESSER CO. 100 IAee Dae ee 7 CYCLES X GO DIVISIONS MADE IN U.S.A, 1600 19 20 Fig. l. 40 60 80 100 120 MEV 140. 160 180 200 Gamma-ray spectrum of sediment from Bravo Crater collected at a water depth of 160 feet, August, 1969.