PHILIPPINE - MARIANA 

 TRANSECT ZONE 



9 aSQP S -ei 

 • Oredges 



Locations of all SEATAR data collected within the Philippine 

 track lines, Deep Sea Drilling Project coring sites, and dredge 



Mariana Transect Zone during the past 15 years. Geophysical 

 locations arc shown. 



Manganese Nodule Program (MANOP) 



IDOE-sponsorcd studies of deep-sea manganese nodules 

 changed focus in 1977 with the initiation of MANOP (the new 

 Manganese Nodule Program) lis predecessoi programs succes- 

 sively compiled unpublished data on distribution and composi- 

 tion of nodules, and surveyed and sampled a number of small 



areas within the hand of coppei and nickel-rich nodules south 

 and east of Hawaii (lie 39). MANOP is concentrating on the 

 paths and mechanisms that carry economical important ele- 

 ments, such as copper and nickel, to the sea Boot and lead to 

 their incorporation in the nodules. Projects are listed in table 14 

 The first approach is to measure all the metal fluxes to a 

 given site on the abyssal sea floor. Sediment traps moored in 

 the water column will record the rate of input from the falling 

 remains of shallow living plants and animals. The rate of supply 

 of dissolved metals from near-bottom waters will be estimated 

 from detailed profiles of chemical analyses of water samples 

 A sophisticated Bottom Lander (fig. 40) will measure the release 



64 



and uptake of dissolved metals at the sea floor. By comparing 

 the Lander values with metal concentrations in pore waters ex- 

 tracted from sediment cores or in situ pore-water samplers, it 

 will be possible to determine what fraction of the metals is de- 

 rived from upward migration through the sediments and what 

 fraction is released by the dissolution or decomposition of par- 

 ticles recently deposited on the sea floor. The fluxes of metals 

 into nodules and sediments will be estimated from radiometri- 

 cally determined rates of accumulation combined with chemical 

 analyses of various components of the solid phases. The com- 

 parison of flux values in areas of metal-rich nodules with values 

 in areas of metal-poor or no nodules will establish whether the 

 supply of metals or the growth mechanism is primarily respon- 

 sible for the development of economically attractive nodules. 

 The second approach is experimental. The Bottom Lander 

 will be used to measure metal-release rates in both enclosed, 

 but undisturbed, nodule-sediment patches and in enclosed adja- 

 cent patches, which will be treated with a mixture of antibiotics 



Figure 39. — Nodule distribution map. 



65 



