558 CYCLES OF ORGANIC AND INORGANIC SUBSTANCES 



Unfortunately, It Is hard to say what the dissolved aluminum 

 species will be. At somewhat higher acidities, aluminum Is known 

 to form unexpectedly large complexes. For Instance, discrete 

 groups AI13O40H4S'"'" have been found In crystal structures 

 (Johansson, 1960; Johansson et al., 1960), and similar complexes 

 are also likely to exist In solution (G. Bledermann, unpublished). 

 The concentrations of Al In sea water reported earlier range from 

 approximately 10~^-° to 10~^'JVf. According to Sackett and 

 Arrehnlus (1959) the concentration of dissolved Al Is only between 

 10~'-' and 10~'-°ik/". We shall have to leave open the question of 

 whether A\ exists mainly as an aluminum polylon, or as a mono- 

 nuclear species, like AKOH)'*"^ or A1(0H)3. The hydrolysis of 

 aluminum Is under active Investigation in Stockholm, and we may 

 know more In a decade or so. At any rate, this soluble aluminum 

 species must play an Important role In the building up of various 

 silicate minerals. 



Chloride and Main Cations 



Next come seven elements in amounts of the same order of 

 magnitude, between 0.41 and 0.76 mole liter sea water. Let us 

 set aside the Iron for a time, to be added later, and also the carbon. 

 In the form of 0.46 mole CaCOs and 0.09 mole MgCOs. Thus, we 

 add to our equilibrium mixture 0.55 mole HCl, 0.76 mole XaOH, 

 0.41 mole KOH, 0.44 mole MgO, and 0.10 mole CaO. This will 

 lead to a rearrangement of part of the solids. Whereas an excess 

 of quartz still remains, part of the quartz and perhaps all the 

 kaollnite Is rearranged to alumlnosillcates with a charged alumlno- 

 sillcate framework, in which Mg may have replaced some Al 

 and Na+, K+, ]\Ig+"*', and Ca+^ may ha\e entered the holes 

 of the framework. Glauconite is an example of an alumino- 

 slllcate with a layer structure. It is abundant In marine sedi- 

 ments and belongs to the mica group of the clay minerals. For 

 glauconite the average formula Ko.R2Nao.09Cao.06Mgo.40Fe1.t6 

 Alo.s2Si3.650io(OH)2 has been given (Jasmund, 1955, p. 154). An 

 abundant alumlnosilicate with a zeolite structure Is phillipsite, 

 which may be written as (M'Si,M"Al)AlSl20s(H20)3, with 

 M' = Na or K, M" = Ca or Ba. 



Although numerous studies have been made on the ion exchange 



