Study Of Evaluation Of Co-rich Ferromanganese Crust Resources On Seamounts In Northwest Pacific Ocean

In this paper, delineation of cobalt crust blocks and evaluation of co-rich ferromanganesecrust deposit over seamounts in northwest pacific ocean are studied to conclude different cruststype, its distribution characters and prospecting indicators.The thesis attempts to introduce theevaluation methods applied in land mineral resource to ocean in order to estimate the amount ofseamounts cobalt crust resource in pacific.This paper provides data and theoretical guidance topresent crust ore-finding, ore-delineation and resources assessment.Based on the data such asmultibeam echo sonar system(MBES), deep-sea video recording and geological sampling onfive seamounts from China,the application of echo intensity data of MBES in forecast ofseamount crust distribution is researched,as well as the amount of co-rich crust resources of thestudy area (whole pacific and northwest pacific) is estimated with different methods based ondownloaded public available data. A new method of man-machine interactive mining delineationis put forward.In the pacific(135°E～100°W，65°S～60°N), the area of9,190,000km2outside thecontinental shelf beyond200sea miles occupies63.7%of the total area of145,250,000km2ofPacific ocean. where the area of cobalt crust prospective areas is6,460,175km2accounting for55%which means less than100seamounts can be used for application. Almost all the Marshallseamounts and half of Marcus-Wake Seamounts are located in the200miles of the continentalshelf which is inferred that Magellan seamounts and part of Marcus-Wake seamounts is thesignificant area of cobalt-rich crusts for further study and application.In the thesis it is found that deep-sea video recording interpretation data and cobalt crustsampling data agrees well with the echo intensity grayscale image by the study of two type ofseamount including of one conical seamount and two flat-topped seamounts as sample. Thethesis sums that the unfavorable area where has no crust or few crust can be distinguished by theshaded area of grayscale image, which provides a new method for ocean cobalt crust resourceevaluation delineation of co-rich crust enrichment sections. The calculation method of seamountarea is improved as well. Based on knowledge of forming principle of co-rich ferromanganesecrust and combined with the comprehensive survey data, each seamount is endowed with thecrust thickness according to its height and age of ocean crust and consequent distributed area ofcrusts over seamounts in Pacific is estimated to be5469390km2, the amount of wet co-rich ferromanganese crust resources2043.145～4000.89108t, and amount of dry crust resourceand contents of metal are also calculated.The thesis also takes the northwest pacific（148°E～171°E，9°N～25°N）as the study object, using geological block method the seamountssurface area above5,000m water depth of Marcus-Wake seamounts, Magellan seamounts andMarshall seamounts are estimated to be879,780.7km2totally, the amount of dry co-richferromanganese crust resources99.684108t.With same method the seamounts surface areaabove3000m water depth are estimated to be204,525.9km2, the amount of dry crust resources27.170108t.Combined with the crusts distribution of pacific seamount and the parameter index of minedelineation to meet the ocean cobalt crust mining applications and development needs,the basicprocedure of oceanic seamount cobalt crust mining delineation and resource evaluation isproposed. The thesis puts forward a new method of man-machine interactive mining delineationsimilar to seed fill algorithm based on the model of mining selection which was proposedthrough the International Seabed Authority(ISBA),as well as the crusts distribution of Pacificseamount and the parameter index of mine delineation,and takes Lamont guyot and MagellanGovorov guyot as sample. The methods of delineating the resource perspective area,man-machine interactive mining delineation and calculation of cobalt crust resource amount aredescribed in detail. Compared with crust application mine region obtained with the griddifferential law by Japan and the distribution character of hydrothermal sulfide application mineregion by Russia and France, the man-machine interactive delineation method proposed in thispaper has obvious advantages.