SECT. 3] 

 II 



PEIiAGIC SEDIMENTS 



669 



Hydrochloride (Reducible); in 1m HCL (Acid-Soluble) and in the Insoluble 

 Manganese Nodules 



Mo Pb'' Ti'' 



Sc La Y Yb Zr^ Th^ Ba . Sr Nb 



* p. tr. = possible traces. 



c Colorimetric determination. 



The residue also contains the terrigenovis minerals, which are embedded in the nodules 

 in varying amounts (mainly quartz, feldspar [of which the calcic plagioclase is partly 

 dissolved by HCl], pyroxene, hornblende, mica residue and spinels), further authigenic opal, 

 authigenic and terrigenous rutile and anatase (carrying the niobium), and finally the more 

 complete authigenic pseudomorphs of rare-earth zirconium-thorium phosphates after 

 apatite. The residue of Nth Hoi 10 was separated in two density fractions by centrifugation 

 in a Clerici solution with p = 3.0. 



Concentrations are given in parts per million. (Spectrographic analyses by A. Chodos and 

 E. Godijn, California Institute of Technology; colorimetric measurements of Zr, Ti, and Th 

 by J. Korkisch, University of Vienna.) 



