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Size analyses and geochemistry of ferromanganese nodules from the Central Indian Ocean Basin

DRS at CSIR-National Institute of Oceanography

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Title Size analyses and geochemistry of ferromanganese nodules from the Central Indian Ocean Basin
 
Creator Valsangkar, A.B.
Khadge, N.H.
 
Subject Geology and Geophysics
mineralogy
correlation
size
ferromanganese nodules
geochemistry
ISW, Central Indian Ocean
 
Description Ferromanganese nodules collected during the 13th cruise of the M.V. Skandi Surveyor in 1987 cover a very large area, 71 424 km super(2) in the Central Indian Ocean. The area consists of 13 nodule types, which are grouped into six size classes. Morphology indicates that spheroidal and ellipsoidal nodules of rough type (Sr) belonging to classes 1 ( 2 cm) and 2 (2-4 cm) are more abundant. The concentration of Mn, Fe, Cu, Ni, and Co in 84 samples varies inversely with size class and only class 1 and 2 nodules are found to be enriched in Mn, Cu, Ni, and Co. Excellent correlations are observed between Mn with Cu and Ni and Fe with Co, whereas Mn and Fe behave inversely in all the size classes. The estimated growth rates are inversely related to size and suggest that the smaller nodules of classes 1 and 2 grow rapidly because of an additional source of the transitional elements. Mineralogy of 36 different size nodules shows decreasing abundance of todorokite with increase in size. Systematic compositional variation observed between the six nodule classes is related to the morphology, mineralogy, and contribution of biogenic matter. The nodules of classes 1 and 2 have a higher grade ( 2.47% of Cu + Ni + Co) and a higher percentage of abundance relative to the nodules of other classes. The study also implies the importance of selection of size parameter when designing the nodule collector
 
Date 1995-06-24T10:01:50Z
2017-09-30T01:29:59Z
1995-06-24T10:01:50Z
2017-09-30T01:29:59Z
1989
 
Type Journal Article
 
Identifier Marine Mining, vol.8(3); 1989; 325-347
http://drs.nio.org/drs/handle/2264/7288
 
Language en
 
Relation Mar Mining
SCI