28 subjected to size and microscopic analysis. Anikouchine found that in general aseper seccions of the cores contain finer mean grain sized material than surface sections. Emery et al. (1954) noted small quantities cf acid insoluble clay material finer than 4 uy in Bikini sediments. Emery et al. (op. cit.) set a two-tiered sediment trap in 34 feet of water near the northwest end of Bikini Island. The top compartment was 22 cm off the lagoon floor and collected .34 mg/cm/day of a sediment finer than Emery observed in any cores. The bottom trap adjacent to the lagoon floor accumulated 2.9 mg/cm/day of sediment with grain size distributions similar to the surrounding bottom sediments (Emery et al.,op. cit. p. 39). The porosity, specific gravity, and chemical composition of bulk and individual Bikini sediment components are reported in Emery et a. (op. cit.). The cent onate compounds of Ca, Mq, and Sr totaled greater than 97% of the inorganic constituents of all sediment samples analyzed. One of the few unclassified descriptions of the effects of atomic testing " the sediments of an atoll] lagoon is found in Glasstone (1950), which ‘-"sies a description of the nature of the effects of the 20 Kt underwater "err tect conducted at Bikini. Following the test, investigation of the " ttttor sho.ed thet the nermal coarse-grained calcareous debris near ‘crt site was converted to "mud" in thickness up to ten feet deep. e- +r @ The area mud was found to have a median diameter of 7.5 microns, with 75% “tte ml! less than 20 microns in diameter, and 25% of the mud was less than ~~ rerer in diameter, This distribution of particle sizes is nearly 1og- " teteoen the 2.5 yw and 20 yp diameter limits measured. An estimated 3.68 ‘~-"< yerds of sediment were “blasted out or plac ed in suspension” by weer cesonation and of this 1.42 x 106 cubic yards did not resettle into Checker : rn es cerression, ‘ Fine mud was found on the lagoon bottom over an area