Turbidite is a type of sedimentary rock formed when a river carries or transports pieces of broken rock as it flows. These particles then settle down and are subjected to high temperature and pressures hence forming Turbidite.
The banded iron layers are formed in sea water when oxygen is released by photosynthetic cyano-bacteria. The oxygen then combines with dissolved iron in ocean to form insoluble iron oxides, which precipitated out, forming a thin layer of banded iron formation on ocean floor.