10 
Although manganese nodules are common on the ocean floor, deposits 
of sufficiently high abundance and metallic content to be commercially 
attractive occur in relatively few known places. Commercial interests 
have collected and analyzed a great number of manganese nodules, but 
all publicly known information is based on approximately 600 sam- 
ples.? 1°71 They are found mainly in the Pacific, Atlantic, and Indian 
Oceans. 
180° 
——X DREDGE 
@ CORE 
Ny a 
e- ee 
a Oe ee 
y e REA OF VERY SLOW DEPOSITION 
wo x or ee 
al A 
'p 
on ees ag 
FIGURE 3 
Ferromanganese deposits of the North Pacific are widespread. Limits are a function of increasing rates of deposition toward land and, in the 
south, by rapid accumulation of biogenic carbonate. The highest density of nodules lies between 6 30 N and 20°N. 
= ™\: * = x 
|  [==evpreDce 
@ CORE 
n 4 r a a 4 n r n n 1 + = 
a yoo" 120" 140" 160" 180" 160" 140" 720" 100" 
FIGURE 4 
Most ferromanganese deposits are concentrated along the line of topographic highs which includes the Manihiki Plateau; Line, Cook and 
Society Islands; and the Tuamotu Archipelago. 
Source, Figs. 3 and 4: Horn et al., 1972, op. cit., p. 13. 
® Horn, D. R., M. N. Delach, and B. 'M. Horn. Metal content of ferromanganese deposits 
of the oceans. IDOE Technical Report No. 3, NSF—GX 33616, National Science Foundation, 
Washington, D.C., 1973. 
Horn, D. R., B. M. Horn, and M.-N. Delach. Ocean manganese deposits, metal values 
and mining sites. IDOE Technical Report No. 4, NSF—GX 33616, National Science Founda- 
tion, Washington, D.C,. 1973. 
4 Wrazier, J. Z., and G. Arrhenius. World-wide distribution of ferromanganese nodules 
and element concentration in selected Pacific Ocean nodules. IDOE Technical Report No. 2, 
NSF—GX 34659, National Science Foundation, Washington, D.C., 1972. 
