Conservative behaviour

Elements with conservative behaviour are characterized by vertical profiles (similar to major ion profiles) that indicate essentially constant concentrations with depth. These elements behave like the major ions, having long residence times and being well mixed in seawater. These elements are not major components of seawater, simply because their crustal abundances are very low compared with the major ions resulting in correspondingly low input rates. Elements showing this sort of behaviour form either simple cations or anions (e.g. caesium (Cs+) or bromine (Br-) with low z/r ratios and little interaction with water (see Section 5.2)), or form complex oxyanions (see Section 5.2), for example molybdenum (Mo) and tungsten (W)—which exist in seawater as MoO4- and WOj-respectively (Fig. 6.19). Conservative elements have little interaction with biological cycles.

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