Biogenic Opal Abundance In Pelagic Sediments Determined By Mean Of We-alkaline Process And It Paleooceanography Application

The silicon nature plankton transforms through the biochemistry function the sea water in soluble silicon for the amorphous silicon constitutes respective skeleton, after dies deposits in the seabed forms the silicon deposit, these silicon deposit are the biogenic opals. The contents of deposit opal on the grounds may calculate the speed of opal to pile up, the change of the speed of opal piled up directly to reflect the past superficial water productive forces change.In 1989,Mortlock R.A and Eroelich P.N proposed molybdenum -blue method, and for example straight took over the use of the infrared-dispersion of light luminosity mirror examination indefinite opal with other test methods, the direct calculation method of microfossil and so on conducts the contrast research, the confirmation molybdenum-blue method is one kind of the more fast, the more simple test opal content wet- alkaline process。Since this method has used to determine the opal content in the deposit in past Pliocene ,the determination object opal content may in 3%--100% between, the error be smaller than 3%.Opal contents variety in the sediments of distant ocean had been use in the pelaooceangraphy research。The domestic and foreign partial scholars already took the opal content variety as one of the pelaooceangraphy superficial water productivity index in some ocean research.The variety of opal content is one of the index sign that the pelao- productivity has conviction most in the deep-sea deposition record. This text which used the molybdenum -blue method determination the biogenic opal of the west Pacific Ocean calcareous ooze (MD982182), the North Atlantic Ocean calcareous ooze (IODP 1312), contains the diatom heavy clay (IODP1314) , the northeast Indian Ocean tuffaceous silt sandstone clay (BAR9427) and so on to have the opal content that the representative's marine sediments, combining other environment index signs, to above-mentioned research area of ancient productivity condition with turned into a characteristics to carry on a discussion.Initially establishes each research area glacial - interglacial period opal depositional cycle pattern. The mode of opal content which is high in glacier period, correspondingly lower in interglacial period in the north Atlantic Ocean and the west Pacific Ocean-east Indian Ocean transition area could temporarily decide"the non- living creature broken bits importation dilution mode"; The change has a more close connection with the changed of surface current strong or weak , terrigenous clasticr or volcano eruption thing import in the research area; The mode of opal content which is low in glacier period, correspondingly higher in interglacial period in the West Pacific Ocean warm pond area could temporarily decide"the type of the living things deposits mode", the deposit studying area is main is that carbonas and opal sediments, change behaviour puts up mutual dilution , this grows the trend that eliminates. Matter imports of terrigenous clasticr is very few.