Petrology Of The Substrate And Research On The Relationships Cobalt-rich Crusts With Substrate In The Western Pacific Seamounts

As an important part of the Western Pacific Seamounts area. Petrology of the substrate andresearch on the relationships cobalt-rich crusts in the Western Pacific Seamounts can help us find out the important effect of the characteristic seamounts formation, consequently knowing geochemical characteristic of the substrate in seamounts. Researching the basalts of seamounts and the development of the seamounts formation is very important to the Co-crusts study and ditribution rules.The paper reports the result of a petrological geochemistry study of a few seamounts, These samples are CLD01-1(1),CLD01-2,CLD01-1(3)( 160°44′36″E, 21°44′52″N),deep warter is 2019m and MID21-11(149°36.0349′E, 20°25.8708′N),deep warter is 1996m . Research make know the samples from western Pacific Ocean seamount, are alkalic basalts and basaltic volcanic breccia. The basalt is altered, the minerals assemblages are plagioclase(Ab60.0An39。2Or0.8), K-feldspar(Or100), pyroxene mostly of clinopyroxene, always be explain by hornblende and apatite.Olivine mainly altered become chlorite minerals. Volcanic breccia mostly have drossy of basalt, character of minerals and structure with ares of basalt is similar. Pyroxene of basaltic volcanic breccia is mostly of augite. On the basis of characteristics of the basalt and basaltic volcanic breccia from western Pacific Ocean seamount and the composition changes of the vesicle filling,this paper will discuss relation between the overlying cobalt crust and the seamounts basalt.The bedrocks for cobalt-rich crusts are the alkaline basalt and basaltic volcanic breccia. The alkaline basaltic vesicle filling with S-type and C-type, S-type and C-type vesicle filling does not exist in one vesicle. S-type vesicle filling composition rich in Si, Fe, K, Mg, Al and Co content generally changes between 0.17% and 0.46%. S-type vesicle filling composition is similar to the composition of alkali basalt. S-type vesicle filling source may be the alkali basalt. C-type vesicle filling composition is rich in O, Ca, C and with a small amount of Si, Al, Mg, Fe, K and other elements, which may be related with ocean water material deposition. The deposition process ofthe S-type vesicle filling reflected Si, Al, Fe, Mg, K and other elements is similar to the early trends of the deposition process of cobalt-rich crusts. The source of early deposition of cobalt-rich crusts may have relation to the alkali basalt. The source of early deposition of cobalt-rich crusts may be a result of the joint deposition of alkaline basalts and ocean water.The characteristics of major matallic elements content in crust is not overrun major matallic element in seawater and major matallic element in substrate rocks(value ratio of manganese and ferric in substrate is lower in crust. Value ratio of cobalt with manganese, value ratio of nickel with manganese is higher in crust), it explain element in crust mostly from seawater and part of substrate rocks, so the influence of substrate rocks on the growthe of crusts...