Age Of Manganese Nodules Of The Clarion-Clipperton Province And The Problem Of Nodule Maintenance At The Sediment Surface

The radiolarian complexes were investigated in sediments, in manganese nodules located on the bottom surface mainly on a thin layer of the Quaternary sediments, and in sediment covered by manganese crust. A continuous sequence of radiolarian biostratigraphic zones from the Late Eocene to the Early Miocene (40-17 million years) and a regional hiatus between 17 and 1 million years were revealed. Age intervals of radiolarian complexes in nodules are Tertiary mainly Oligocene. The age of the crust is Quaternary, it accrued on eroded surface of the Late Oligocene clay. Deposits of the end of the Late Oligocene as well as of Miocene and Pliocene were eroded and washed away in the Quaternary by near-bottom currents. Probably the erosion began about 0.9-0.7 million years ago at the beginning of <> when the ocean circulation became more active. The erosion of Tertiary deposits by near-bottom currents could be intensified by an effect of strong earthquakes in tectonically active zones of transform faults and subduction. The seismic vibration effect on the surface sediment layer must disintegrate and stir up sediments which are then carried away by the bottom current. Large-size components of the sediment including manganese nodules form residual deposits. The same vibration effect causes ancient nodules to float up onto the surface of the Quaternary sediments. Thus, this hypothesis suggests one and the same reason for the peculiarities of the Clarion-Clipperton zone, that is, the regional stratigraphic hiatus, the formation of the residual nodule fields, and floating up of ancient nodules to the surface of the Quaternary deposits.