DD Fossils

Manganese nodules, also known as Polymetallic nodules, are rock concretions formed on the deep ocean floor by the gradual build-up of layers of iron and manganese hydroxides around a central core. The nodules can be found in vast quantities, and can contain valuable metals, which has made them of interest to mining companies.

Nodules vary in size from microscopic particles to large specimens measuring more than 20 centimetres across, although most are about the size of a golf ball. The nodule surface texture varies from smooth to rough, but many  frequently have a knobbly appearance. Due to being  buried in the sediment, the bottom of each nodule is rougher than the top.

All of the nodules offered on this page were collected in 1979 by the Glomar Explorer, a ship constructed on the orders of Howard Hughes, and made famous for being used by the CIA in 1974 to recover parts of the sunken Soviet nuclear submarine K-129.

In late 1979, OMCO (Oceans Mineral Company), a consortium of several mining companies and Lockheed Martin, commissioned the ship for experimental mining of manganese nodules from the Clarion Clipperton Fracture Zone (below) located three miles deep in the north-east Pacific Ocean. The nodules were collected by a 2,000 tonne hydraulic platform known as the ‘claw’ that was lowered from the Glomar Explorer to the ocean floor. Upon contact with the sea bed the fingers of the claw would close, scooping up a large volume of material. Various stages of filtering removed much of the sediment and sea-life, resulting in hundreds of tonnes of nodules being collectable in a 12 hour period. Despite this apparent success, the process was deemed to be commercially unviable and all intensive mining of the area ceased. The location from which this nodule was collected has not been revisited since the Glomar Explorer expedition of 1979 and is currently outside the area so far licensed for possible future mining.

• All orders come with a full colour ID card displaying much of the above information