"cS Micreszopic chservations of the fallozt collected froa the C°hS truck rvas indicated at least two general types of particles, One type reseubled .Surel coral, while the second wes either partially or totally black. The bleck particles were ferrozagnetie to varying degrees and gave positive quali-~ tative tests for fron, The white particles were composed of both calcium carbonate and calcium hydroxide (or oxide), The lydroxide, or oxide, appeared to be uniformly distributed through the volumes of the particles, On the average, the black particles were individually about four tines as radioactive as the white particles, but the former represented only 20 percent by nu wer of the total particles in the size fractions larger than 50 microns, The radioactivity of both types of particles appeared to be unifornly “eee Lnirough the voluries of the particles, : The bulk density of the sauples fron the Total Pallout Coll:ctor at Site Wititk end fron the GENE truck tarpailin ves 2.6 afer, sland soil was found to be 2.70 - 2.75, ~ 35 - ~