not sufficient to accurately estimate Pu inventory separately for mounds. Also, no information was obtained on amounts of Pu below 5 cm in mounds. Profiles to 25-cm depth were taken, but only in desert pavement areas. In October, 1974, a mound study (now given the title Mound Study 1) was conducted near ground zero at C Site in Area 11 on NTS. Profile samples (each with ten 2.5-cm depth increments) in ten blow-sand mounds and ten adjacent desert pavement locations were collected and analyzed for Am using REECo's Ge(Li) system. These data were taken to obtain information on the distribution of Am with depth in mounds versus that in desert pavement. The results of this study have been discussed by Gilbert et al. (1975), Brady (1976), and Essington et al. (1977). This study indicated that for each 2.5-cm depth increment from the surface of the blow-sand and desert pavement profiles, the average Am concentration was higher in the blow-sand mound. Also, the depth at which Am occurred was less in desert pavement than in blow-sand mounds; and mound profiles had a smaller fraction of the total Am in the top 2.5 or 5 cm than did desert pavement profiles. Mound Study 2 On the basis of these results, it was decided to initiate a larger-scale mound study (Mound Study (MS)-2) at two safety-shot sites: the Project 57 site in Area 13 and the Clean Slate 3 site on TTR. Information on the motivation, design, and protocol development of MS-2 is given by White and Dunaway (1976, pp. 33-122). Design aspects and results of statistical analyses of the resulting data are given by Essington et al. (1977) and Gilbert and Essington (1977). The primary objective of MS-2 was to estimate the total amount (inventory) of Pu in blow-sand mounds at the two chosen study sites. This was accomplished by sampling entire mounds (actually "mound tops" and "mound bottoms" were collected separately) except for "diffuse" mounds at Clean Slate 3. These mounds were too large to collect in total. Desert pavement samples adjacent to the sampled mounds were also collected for comparison purposes. FIDLER readings over mounds and desert pavement were also taken. A major finding of MS-2 was that roughly 60 to 65 percent of the total (mound top + mound bottom) mound inventory was estimated to be in mound bottoms even though Pu concentrations on a per gram dry weight basis were roughly twice as large in mound tops as in mound bottoms. At Clean Slate 3, about 70 percent of the total surface inventory (mound + desert pavement down to the 5~cm depth datum) was estimated to be in desert pavement areas. In Area 13, the percentage was about 85 percent. The FIDLER readings over mounds tended to be higher than those taken over adjacent desert pavement. This was also the case for soil concentrations when expressed on a per gram basis. Some data on the change in the Pu to Am ratio in soil over time is also presented by Essington et al. (1977) and Gilbert and Essington (1977). 468